HexWiki - User contributions [en]

Win

2012-11-19T22:17:50Z

Roland Illig: Added an example

The game is won when there's a path between opposite sides of the board. The player owning those sides is the winner.

== Example ==

<hex>
R7 C7 border labels
play
d4 d3 e3 f1 f2 g1 e2 e1 b3 c1
a2 a1 b1 c4 b5 b6 d6 d5 c5 c6
f4 e5 f5 e6 f6 f7 e7 b4 d2 d1
c2 b2 a3 f3 e4

red numbered
b1 a2 a3 b3 c2 d2 e2 e3 e4 f4 f5 f6 e7
</hex>

In this game [[Red]] has built a path between the top and the bottom (which are both red). The path is marked with the numbered stones.

Back to the [[rules]]

[[Category:Definition]]

Wolve

2012-11-17T15:12:49Z

Roland Illig: +cat

Wolve is a Hex program developed based on alpha-beta search at the University of Alberta by [[Philip Henderson]], [[Broderick Arneson]] and [[Ryan Hayward]]. Older versions were also developed by [[Yngvi Björnsson]],
[[Michael Johanson]], [[Morgan Kan]], [[Martin Müller]] and [[Geoff Ryan]].

Wolve is Free Software and released under the terms of the Lesser General Public License.

Wolve won the gold medal at the Computer Olympiad 2008.

* [http://webdocs.cs.ualberta.ca/~hayward/hex/#Wolve Information at Ryan Hayward's page]
* [http://www.grappa.univ-lille3.fr/icga/program.php?id=135 Wolve results at ICGA tournaments]
* [http://sourceforge.net/projects/benzene/ Project page at SourceForge with source code release]
* [http://webdocs.cs.ualberta.ca/~hayward/papers/rptBeijing.pdf Wolve 2008 Wins Hex Tournament (13th Computer Olympiad 2008 Beijing) (PDF)]

[[Category:Computer Hex]]

Switchback

2012-11-17T15:12:17Z

Roland Illig: +cat

A '''switchback''' is a situation in which a [[ladder]] moves back two rows and changes direction. The attacker is still in control after the switchback. Although it is not always ladder escape, it often can be and is usually a strong play.

The situation prior to a switchback generally looks like this (assume the piece on D1 is in some way connected to the top):

<hex>R4 C8 Q1 Vd1, Vc2, Vh1, Hb2, Hd2, Hb4</hex>

Red makes a switchback as follows:

<hex>R4 C8 Q1 Vd1, Vc2, Vh1, Hb2, Hd2, Hb4 N:on Vc3, Hc4, Vd3, Hd4, Ve3, He4, Vg3, Hf3</hex>

Now the ladder continues back to the left:

<hex>R4 C8 Q1 Vd1, Vc2, Vh1, Hb2, Hd2, Hb4, Vc3, Hc4, Vd3, Hd4, Ve3, He4, Vg3, Hf3 Vg3 N:on Vg1, Hf2, Vf1, He2, Ve1</hex>

Note here how red was able to connect back to the D1 piece. This is not always possible, but even if it isn't the switchback can be used to create a long line connected to the edge and four rows back from it, a distinct advantage.

== A Different Situation ==

A different kind of switchback can occur on the third row:

<hex>R5 C8 Q1 Vd1, Vc2, Vh2, Hb2, Hd2, Hb4</hex>

If Blue yields the ladder to the second row, then Red can create a switchback as shown above which would continue back and reconnect. If the ladder stays on the third row then Red creates a switchback as follows:

<hex>R5 C8 Q1 Vd1, Vc2, Vh2, Hb2, Hd2, Hb4 N:on Vc3, Hc4, Vd3, Hd4, Ve3, He4, Vg3</hex>

Red's piece on G3 is connected to the bottom. Play continues:

<hex>R5 C8 Q1 Vd1, Vc2, Vh2, Hb2, Hd2, Hb4, Vc3, Hc4, Vd3, Hd4, Ve3, He4, Vg3 N:on Hf3, Vg1, Hf2, Vf1, He2, Ve1</hex>

[[Category:Definition]]

Swap rule

2012-11-17T15:12:00Z

Roland Illig: +cat

Because the [[first player]] has a considerable advantage if he is allowed to make his first move without restrictions, the '''swap rule''' was devised. It states that one player first makes a move, and then the [[second player]] decides who plays with which colour. The swap rule can be implemented in two ways, as follows. (Assume that the colours are red and blue, with red moving first.)

# The first player places a red piece in any hex on the board. Then the other player can either make a move with the blue pieces, in which case he becomes blue, or he can state that he wants to be red. After this the game continues without any more swapping.
# The first player makes a move with the red pieces. The other player either makes a move with the blue pieces, or makes a [[piece swap]]. This means to remove the red piece from the board, and place a blue piece at the hexagon which is the mirror image of the hexagon in which the red piece was placed, with respect to the board's long diagonal.

In face-to-face play the first option is most practical, since it is easier to change colours of the players that removing and adding pieces on the board. It is also less error-prone. On [[Online playing|game sites]] on the Internet the second version is more common, presumably because the colours are determined at the start of the game, and it is easier to change the board position than the colour designation.

The swap rule is also called the "Pie rule", since it resembles the ''You cut, I choose'' rule when sharing a pie between two children.

When playing with the swap rule, the second player has a winning strategy. However, the second player's advantage is much smaller than the advantage of the first player is when playing without swap.

== The generalized swap rule ==
Instead of placing just one piece, the first player can place any number of red and blue pieces, and state which colour has the next move. The second player then decides who has which colour. This version has the drawback that the first player can prepare in advance a position which he has studied extensively, which the second player doesn't see until the game starts, thereby giving the first player an advantage.

[[Category:Definition]]

Rules

2012-11-17T15:11:38Z

Roland Illig: +cat

== Shape of the board ==
The [[Hex]] [[board]] is composed of [[hexagon]]s, arranged in an ''n × n'' [[Wikipedia:Rhombus|rhombus]], where ''n'' is an integer greater than one. Thus Hex can be played on boards of different sizes, and which size is considered standard varies. [[Piet Hein]] used a board of size 11, while [[John Nash]] settled on size 14. Nowadays people usually use the sizes that are available on [[Online playing|game sites]] on the Internet offering Hex. [http://games.wtanaka.com/hex Games.wtanaka.com] uses sizes 11, 14 and 19; [[Little Golem]] offers the sizes 13 and 19. (See the article [[Board size]] for more.)

It is also possible to play on boards of size ''m × n'' where ''m'' and ''n'' are distinct integers, but in this case a winning strategy is known for the player with shortest distance between his sides.

This is how a typical Hex board looks:

<hex>B:on</hex>

== Playing the game ==
Hex is played by two players, who take turns placing pieces on the board. The players have different colours, say red and blue. (The players themselves are sometimes referred to as [[Red (player)|Red]] and [[Blue (player)|Blue]]) The four [[Edge|edges]] of the board are coloured with the same colours, in such a way that parallel edges have the same colour. Red wins if he can build a continuous chain between the two red edges, and blue wins if he can build such a chain between the blue edges.

Example: the following diagram shows a game after the first three moves.

<hex>
R5 C5 Q1 B:on
N:on c3 b5 d4
</hex>

The next diagram shows the rest of the game.

<hex>
R5 C5 Q1 B:on
Rc3 Bb5 Rd4 N:on c4 d3 d5 c5 c2 d2 d1 e1
</hex>

Red has won this game, since he has built a connection from the top to the bottom.

== The [[swap rule]] ==
The above rules give a strong advantage to the [[first player]]. Because of this, the [[swap rule]] (also called the Pie rule) was introduced. Suppose that Red is to make the first move. Then the first player places a Red piece on the board, in any cell he likes. After that, the second player decides who will play Red and who will play Blue. Then whoever was decided to be blue makes the next move, and the game continues normally (that's how it works at [http://games.wtanaka.com/hex games.wtanaka.com] and [http://www.gamerz.net/pbmserv pbmserv]).

Another possibility to swap (without changing sides of each player) is to make a [[Piece swap|piece swap]]. That is, the second player in his first move may remove the first stone which was placed on field with coordinates (x;y) and place his/her own stone on field (y;x). That's how it works at [[Little Golem]]. These two ways of swapping are effectively the same.

== Beyond the rules ==

For more information on how best to utilize the rules, see [[Strategy]].

[[Category:Definition]]

Red (player)

2012-11-17T15:11:24Z

Roland Illig: +cat

One name for the canonical hex player who plays first. Other names may be vertical player or black player.

[[Category:Definition]]

Philip Henderson

2012-11-17T15:11:05Z

Roland Illig: +cat

Philip Henderson is a computer scientist at the University of Alberta and co-author of [[Wolve]] and [[MoHex]]. He published several papers on [[Computer Hex]] and is doing his PhD thesis on this topic.

* [http://webdocs.cs.ualberta.ca/~ph/ Homepage at U of A]
* [http://www.grappa.univ-lille3.fr/icga/person.php?id=289 Participation at ICGA tournaments]

[[Category:Person]]

Niall vs Daniel Sepczuk - Dec 2011

2012-11-17T15:10:52Z

Roland Illig: +cat

Daniel Sepczuk (blue) vs Niall Cardin (red)
Notes about some moves, I start making notes in response to move 25
All blue moves or pieces are in (), e.g. blues first move was at (F1). Nothing else is in ().

== Game information ==
* Size: 13x13
* Red: [[user:Niall | Niall]]
* Blue: Daniel Sepczuk
* Result: 0-1 (Blue won)
* Comments: Niall
* Location: [[Little Golem]], game [http://www.littlegolem.net/jsp/game/game.jsp?gid=1401976] in championship 28.1.1

Moves 1 to 8 (In fact red played A6 which was swapped to F1, so it's labeled as 9 on littlegolem)
<hex>R13 C13 Q1 B1f1 R2i5 B3i10 R4k10 B5k12 R6l11 B7l12 R8j10 </hex>

Moves 9 to 14
<hex>R13 C13 Q1 Bf1 Ri5 Bi10 Rk10 Bk12 Rl11 Bl12 Rj10 B1h12 R2j12 B3j7 R4c4 B5d3 R6d10 </hex>

Moves 15 to 21
<hex>R13 C13 Q1 Bf1 Ri5 Bi10 Rk10 Bk12 Rl11 Bl12 Rj10 Bh12 Rj12 Bj7 Rc4 Bd3 Rd10 B1d4 R2f5 B3j2 R4b3 B5c5 R6j3 B7k2</hex>

This is the position I (red) am considering when these notes start, move 25:
<hex>R13 C13 Q1 Bf1 Ri5 Bi10 Rk10 Bk12 Rl11 Bl12 Rj10 Bh12 Rj12 Bj7 Rc4 Bd3 Rd10 Bd4 Rf5 Bj2 Rb3 Bc5 Rj3 Bk2 R1k3 B2l2 R3g4 B4f8</hex>
Move 26: Daniel thought that G8 was the way to go, though he says he didn't look for long. I didn't like it after G6 from blue.
- G6
- (E9) G8 (F10) G10 (G9) I8 (I6) H7 - might work for red?
- (E7) G8 (F10)
- (F6) E5?
- (H6) E8 (F6) E5 (E6) F7 (G5) H5 - assert that H5 is connected to the top with C3 and E5
- G8
- (G6)
- G7 (F7) I3 (H6) I6 (H7) I7 (H9) H8 (F9) G9 (F11) - looks good for blue
- E8 (E7) F7 (F6) - blue wins
- H7 (H3) E5 (H4) E8 (E7) - blue wins
- (H6)
- E8 (F6) H5
- (G7) H7 - looks like a win for red
- E8 (F6) G6 (F7) G8 (F10)
- I6 (H7) I7 (H9) H8 (G8) G9 (G10)
- E7 (G6) I3 (D9) - looks good for blue
- G7
- (F10)
- G8 (E12) F9 (E10) E9 (C12) - looks good for blue
- E8 (F6) F7 (H5) I3 (H6) I6 (H7) I7 (H9) H8 (G8) G9 (G10) - looks good for blue
- (G8) E8 (F6) F7 (H5) I3 (H6)
- (F7) G8 (G6) I3 (H6) I6 (
- (E9) G9 <(F10) G10 (F12) H11> (G8) I7 (H8) I8
- (E10) E8 (F6) F7 (H5) I3 (H6) I6 (H7) I7 - red connects
- H7
- (E10) H8
- (H9) - looks like blue wins
- (I9) G10 - red wins
- (H8) G8 (F9) G9 (F11) - seems like red can't get through
- I7 (H9) - good for blue

Variations if I play G8 that I noted in the game. I was worried about this G6 response, threatening H3:
<hex>R13 C13 Q1 Bf1 Ri5 Bi10 Rk10 Bk12 Rl11 Bl12 Rj10 Bh12 Rj12 Bj7 Rc4 Bd3 Rd10 Bd4 Rf5 Bj2 Rb3 Bc5 Rj3 Bk2 Rk3 Bl2 Rg4 Bf8 R1G8 B2G6 </hex>

Red variation 1a
<hex>R13 C13 Q1 Bf1 Ri5 Bi10 Rk10 Bk12 Rl11 Bl12 Rj10 Bh12 Rj12 Bj7 Rc4 Bd3 Rd10 Bd4 Rf5 Bj2 Rb3 Bc5 Rj3 Bk2 Rk3 Bl2 Rg4 Bf8 RG8 BG6 R1G7 B2F7 R3I3 B4H6 R5I6 B6H7 </hex>
Red variation 1b
<hex>R13 C13 Q1 Bf1 Ri5 Bi10 Rk10 Bk12 Rl11 Bl12 Rj10 Bh12 Rj12 Bj7 Rc4 Bd3 Rd10 Bd4 Rf5 Bj2 Rb3 Bc5 Rj3 Bk2 Rk3 Bl2 Rg4 Bf8 RG8 BG6 RG7 BF7 RI3 BH6 RI6 BH7 R1I7 B2H9 R3H8 B4F9 R5G9 B6F11</hex>

Red Variation 2
<hex>R13 C13 Q1 Bf1 Ri5 Bi10 Rk10 Bk12 Rl11 Bl12 Rj10 Bh12 Rj12 Bj7 Rc4 Bd3 Rd10 Bd4 Rf5 Bj2 Rb3 Bc5 Rj3 Bk2 Rk3 Bl2 Rg4 Bf8 RG8 BG6 R1E8 B2E7 R3F7 B4F6</hex>

The move I actually played and blues response:
<hex>R13 C13 Q1 Bf1 Ri5 Bi10 Rk10 Bk12 Rl11 Bl12 Rj10 Bh12 Rj12 Bj7 Rc4 Bd3 Rd10 Bd4 Rf5 Bj2 Rb3 Bc5 Rj3 Bk2 Rk3 Bl2 Rg4 Bf8 R1g6 B2f6</hex>
Move 28:
- I7
- (H9) I8 (I9) K8 (J8) G9 (H7) H8 (I6) K5 (J6) L6 - red wins
- (G9) H9 (G11) F9
- (G8) G10 (F11) F10 (C12) D12 - red wins
- (F10) G8 (C12) F11 - red wins
- (G5) I3 (H6) J6
- G8
- (G5) I3 (H6)
- G7 (H5) - same old ladder towards the bottom that I seem to lose after (C12)
- H5 (G7) - same old la... " "
- (F10) F9 (C12) C10 (B12) F7
- (E11) G10
- (G5) I3 (H6)
- F7
- (G5) I3
- (H6)
- H5 (E8) G8 (G7) - think blue wins, as I didn't get C10
- E7 (D9) - looks like blue wins
- (E8)
- G8 (F10) F9 (C12) C10 (B12)
- E7 (H7) - blue wins
- G8 (G5) H5 (H3) - blue wins. E5 (D4) exchange doesn't help

<hex>R13 C13 Q1 Bf1 Ri5 Bi10 Rk10 Bk12 Rl11 Bl12 Rj10 Bh12 Rj12 Bj7 Rc4 Bd3 Rd10 Bd4 Rf5 Bj2 Rb3 Bc5 Rj3 Bk2 Rk3 Bl2 Rg4 Bf8 Rg6 Bf6 R1i7 B2h9 R3i8 B4j9 R5h10 B6i9 </hex>
Move 34:
- E7
- (E6) F7 (G5) I3 (D9) E9 (E8) G8 - red wins
- (D9) E9 (E8) G8 - red wins
- G8 (F10) F9 (C12) C10 (B12) E9 (E11) - blue wins

<hex>R13 C13 Q1 Bf1 Ri5 Bi10 Rk10 Bk12 Rl11 Bl12 Rj10 Bh12 Rj12 Bj7 Rc4 Bd3 Rd10 Bd4 Rf5 Bj2 Rb3 Bc5 Rj3 Bk2 Rk3 Bl2 Rg4 Bf8 Rg6 Bf6 Ri7 Bh9 Ri8 Bj9 Rh10 Bi9 R1e7 B2e6 R3f7 B4d9 R5e9 B6e8</hex>
Move 40:
- L8
- (K6) J8 (K8) L7 (K7) G9 (H7) H8 (I6) J6 (J5) L4 (K5) M4 - red wins
- (K7) G9 (H7) H8 (I6) J6 (J5) L4 (K5) L5 (K6) M6 - red wins.

Niall: Here is a summary at move 42 , the game has clearly been won by blue.
<hex>R13 C13 Q1 Bf1 Ri5 Bi10 Rk10 Bk12 Rl11 Bl12 Rj10 Bh12 Rj12 Bj7 Rc4 Bd3 Rd10 Bd4 Rf5 Bj2 Rb3 Bc5 Rj3 Bk2 Rk3 Bl2 Rg4 Bf8 Rg6 Bf6 Ri7 Bh9 Ri8 Bj9 Rh10 Bi9 Re7 Be6 Rf7 Bd9 Re9 Be8 R1l8 B2l7</hex>
The key moves are G8 and G9. However:
- G9 (H7) H8 (I6) - blue connects
- G8 (F9) G9 (F11) F10 (E11) E10 (C12) - blue connects
Red cannot threaten the blue connections to the right with C10 or similar, (C5) stones deal with everything.
B10 (C8) exchange doesn't block (C12).

Red can deal with (H3) and (G5) related complications. I3 is a key move for most of these variations.
Also
- (G3) H3 (I1) F2 and red connects.

The game then happens to continue like this, so that red can ask blue where he went wrong :)
<hex>R13 C13 Q1 Bf1 Ri5 Bi10 Rk10 Bk12 Rl11 Bl12 Rj10 Bh12 Rj12 Bj7 Rc4 Bd3 Rd10 Bd4 Rf5 Bj2 Rb3 Bc5 Rj3 Bk2 Rk3 Bl2 Rg4 Bf8 Rg6 Bf6 Ri7 Bh9 Ri8 Bj9 Rh10 Bi9 Re7 Be6 Rf7 Bd9 Re9 Be8 Rl8 Bl7 R1k8 B2j8 R3g8 B4f9</hex>

[[Category:Game record]]

NiallVsWojtex 1252454

2012-11-17T15:10:31Z

Roland Illig: +cat

Some plain text notes to myself about the game:
http://www.littlegolem.net/jsp/game/game.jsp?gid=1252454
**...** means that this sequence comes up again and again.
<...> means that this sequence is an optional exchange

Move 34:
C5 <<J5 H6> (D5) C6 (C3) B5> (D7)
- G3 (E5) E3 (F3) [blue can't afford a ladder to the right, so] G1 (F2) F1 (D2) E2 (D4) - red solidly connects, and wins
- F4 [connected to the left edge] (G5) K3 (H3) I2 (G2 - ladders to F2, then jumps to D2) - red wins
F2
- (D2) C5 (D7)
- (K3) D7 (C5) E1 - red seems to have made things hard for himself
D4 (C3) B6 (F4)
- D7 (C6) D5 (C5), and (C3) blocks blue
E4 (D5) E5 (C3) D2 (E3) F1 (G2) G1
G3 (D7) E4 [problems at D4, but ignore for now] (J5) K6 (G5) K3 (I3) H4 (I4) H5 - blue wins

Move 30:
G3
- (C3) E3 (D2) D5 (G5) C6 (D6)
- (D6)
- E4 (D4) - seems like a red win?
- C5 [if (D4) then D7 is a win for blue] (E4) F2

D6
- (J5)
- K3 (G5) G3 (I3) H4 - looks good for blue, locally? Blue (E4) area ?
- K6 (D7) F4 (E5) E4 (D5) D3 (D2) C3 (G5) K3 (H3) I2 (G2) - red wins!
- (D5 forcing blue to choose?)
- D7 (B7) C5 (C6) E3 (D4) D3 [bad shape] (J5) K3 (G5) J2?
- B7
- C5
-
- (G4) D7 - blue wins
-
- <(B7) C5 (D5) C6> (C3) F2 (D2) B5 (D7)
- E4 [connects to left edge, and H1] **(J5) K6 (G5) K3**
- F4 (E5) D4 (E3) E4 (F3)

F4
- (D6 - connects C4 to the bottom, but C4 isn't at the top yet), however with the J5 exchange so far it looks like red makes it.
- (D5) <E3 (D2)> D6 (B7) C5 [everything very disconnected now!]
- (J5) H5 (G6 I hope!) K3

My basic question is: Before I play E/F4 leading to: **(J5) K6 (G5) K3**, do I gain from forcing anything? Also, which is better out of E4 and F4? F4 looks nicer on the surface. Can I get to F4? I think I can, even after (B7) sequence, but only if red hasn't played (D2).

E4 (J5) K3 (J3) - I need H5 force, hence <K6 (G5)> exchange.
F2 (D2, more efficient than just D2 directly!) <D3 (C3)> D6 (E4) D4 (C5) B7 [forced if <D3 (C3)> played, if not, then should play at this point?] (D7 - forced) D5 - very bad for red I think. Will have a way around this. Probably by forcing at (J5) and playing something like (I3) now
E4/F4, planning to play K3 after red forces with (J5) and then plays (G5)
D5 (B6) <B7 (D6)> F4...

Move 28:
D6 (E7) D8 (E8) G4 **(J5) K6 (G5) K3**
E7 (C8) D6 (D7) F4 (J5) **K6 (G5) K3** (I3) H4 (I4) H5 (G6) J4 - no local win for red...
F5 (E7) - doesn't look promising to me
G6 (F6) - blue fail
D8 (E8) F6 (E7) - bad for blue

Move 24:
F2 - threatens C2, or is it better to play C2? Trouble is that C2 (J5) K6 (E7) red seems quite close to the top.
D8 (C7) - very effective looking for red!
D8 (E8) F6 (E7) E5 (D6) D5 (B6) C6 (B7) C7 (B8) C9 - win for blue
D8 (E8) F6 (E7) E6 (D7) D6 (B7) - bottom ladder works for red. Top left ladder leads to ladder along the top past H1, but with J5 it looks like red has it
D8 (D7) F6 (B9) C6 - blue wins
E5 (E6)
E5 (E6) D8 (E8) E7 (F7) G6 (J5) K6 (F6) G4 - [red now has 2 attacks, he can play both]
top right - (G5) H4 (H5) K3
middle left - C6
middle left - D6
Note: C2 doesn't look very powerful: (B3) B2 (C3) - runs to top right, but with (J5) force red looks good.
E6 (F7) - bad for blue?
Looking bad for blue...
Problem: Red can force at J5 - making H6 very close to the top. So, D9 only has to get to C4, H6 or the top.

[[Category:Game record]]

Move

2012-11-17T15:09:31Z

Roland Illig: +cat

A [[Hex]] move can be one of the following:

* Placing a stone on an empty cell of the board.
* Swapping colors, usually only legal as the second move of a game.
* Swapping pieces, usually only legal as the second move of a game.

== Move numbers ==

Go players are used to give each move its own number (see for example [[Help:Hex|the help page for hex diagrams]]).
Chess players are used to give one number to two consecutive moves (see for example [[Wroclaw_game_01]]).
Here, both variants are used.

== References ==
* http://www.red-bean.com/sgf/hex.html

[[Category:Definition]]

MoHex

2012-11-17T15:09:20Z

Roland Illig: +cat

MoHex is a Hex program based on Monte Carlo tree search developed at the University of Alberta by [[Philip Henderson]], [[Broderick Arneson]] and [[Ryan Hayward]].

MoHex is Free Software and released under the terms of the Lesser General Public License.

MoHex won the gold medal at the Computer Olympiad 2009.

* [http://webdocs.cs.ualberta.ca/~hayward/hex/#MoHex Information at Ryan Hayward's page]
* [http://www.grappa.univ-lille3.fr/icga/program.php?id=555 MoHex results at ICGA tournaments]
* [http://sourceforge.net/projects/benzene/ Project page at SourceForge with source code release]
* [http://webdocs.cs.ualberta.ca/~hayward/papers/rptPamplona.pdf MoHex Wins Hex Tournament (14th Computer Olympiad 2009 Pamplona) (PDF)]

[[Category:Computer Hex]]

Miai

2012-11-17T15:09:03Z

Roland Illig: +cat

'''Miai''' is a Japanese term taken from [[Go]], which is also very useful in [[Hex]]. It means that a player has two different options for achieving a specific goal, usually connecting two groups of pieces.

The most basic example is the [[bridge]] as seen below, where the starred cells are said to be miai; if [[Blue (player)|Blue]] plays at one of them, [[Red (player)|Red]] secures his connection by playing at the other.

<hex>R4 C4 Vb2 Vc3 Sb3 Sc2</hex>

== See also ==

[[Multiple threats]]

== External link ==

* [http://senseis.xmp.net/?Miai Article in Sensei's Library on Miai in Go]

[[Category:Definition]]
[[Category:Strategy]]

Maciej Celuch

2012-11-17T15:08:43Z

Roland Illig: +cat

Maciej Celuch is a Polish Hex player.

He is ranked #1 on [[Little Golem]], and is considered the strongest Hex player in the world by a good margin. He is more than 100 elo ahead of the runner up in 13x13 Hex on Little Golem, and more than 300 elo ahead on 19x19.

Maciej Celuch also plays under the nickname nie_wiesz ("don't know" in Polish) on [[igGameCenter]] and other Hex sites.

[[Category:Person]]

Liberty

2012-11-17T15:07:08Z

Roland Illig: +cat

A '''liberty''' of an [[isolated piece]] or a [[group]] is the number of unoccupied [[Hex (board element)|cells]] [[adjacent]] to it. A piece with few liberties is generally weaker than one with many liberties.

''Do not play an isolated piece with three or fewer liberties.'' Such a move is always a bad move — it is always possible to find a better one.

[[Category:Definition]]

Isolated piece

2012-11-17T15:06:56Z

Roland Illig: +cat

An '''isolated piece''' is a [[piece]] which is neither [[adjacent]] to any [[friendly piece]] nor to a [[friendly edge]].

[[Category:Definition]]

Irrelevant move

2012-11-17T15:06:40Z

Roland Illig: +cat

An '''irrelevant move''' is a move that does not improve the position of the player who makes the move. It is considered as a waste of time and has to be avoided. The most obvious irrelevant move one can play is playing in a [[useless triangle]].

Typically irrelevant moves occur in [[dead cell]]s.

[[Category:Definition]]

HexGui

2012-11-17T15:05:43Z

Roland Illig: +cat

HexGui is a modified version of the application GoGui, for the game Hex. It was created mainly to have a Windows version of the open source engine [[Six]] (originally a KDE-Application by Gábor Melis).

GoGui is a tool for Go programmers and players, to display Go game trees, save them in .sgf format, attach an engine and debug it (analyze mode). Also some smaller non-GUI tools like TwoGtp (test two engines against each other) are included. GoGui is an open source application, written in Java, by Markus Enzenberger.

In HexGui, some features were removed (e.g. "set up" a position), and tools like TwoGtp may be untested, but could quite easily be made working again.

Link: [http://mgame99.mg.funpic.de/hex.php HexGui homepage]

References:
http://gogui.sourceforge.net/,
http://six.retes.hu/

'''Note:''' There is also another program named HexGui and derived from GoGui. This program is the GUI that the authors of [[MoHex|Mohex]] and [[Wolve]] recommend on [http://benzene.sourceforge.net/ their web page]. It is available at http://webdocs.cs.ualberta.ca/~broderic/hex/

[[Category:Computer Hex]]

Coordinates

2012-11-17T15:04:00Z

Roland Illig: +cat

The cells on the Hex board are referred to using '''coordinates''' of a letter and a number, e. g. [[a1]] or c14. The letter usually gives the column, the a-column being at the left side of the board, and the number gives the row, row 1 being at the top side. A1 is an [[acute corner]], having two adjacent cells. It is assumed that the first moving player is vertical, i. e. has to connect the rows 1 and n on an n x n board.

[[Category:Definition]]

Broderick Arneson

2012-11-17T15:03:47Z

Roland Illig: +cat

Broderick Arneson is a software developer at the University of Alberta and co-author of [[Wolve]] and [[MoHex]]. He is co-author of several papers on Computer Hex.

* [http://www.grappa.univ-lille3.fr/icga/person.php?id=288 Participation at ICGA tournaments]

[[Category:Person]]

Blue (player)

2012-11-17T15:02:39Z

Roland Illig: +cat

One name for the canonical hex player who plays second (swaps). Other names may be horizontal player or white player.

[[Category:Definition]]

Wroclaw game 06

2012-11-17T15:00:35Z

Roland Illig: Changed hex markup to "play mode"

'''Red player:''' Marius Halsør 
'''Blue player:''' David Rydh 
'''Date:''' 2005-05-07

{|
| 1. b2 || e6
|-
| 2. h5 || i10
|}

<hex>
R13 C13 Q1 play numbered b2 e6 h5 i10
</hex>

{|
| 3. h10 || i11
|-
| 4. f10 || g7
|}

<hex>
R13 C13 Q1 play b2 e6 h5 i10 numbered h10 i11 f10 g7
</hex>

{|
| 5. f7 || f8
|-
| 6. d9 ||
|}

<hex>
R13 C13 Q1 play b2 e6 h5 i10 h10 i11 f10 g7 numbered f7 f8 d9
</hex>

{|
| 6. ... || e8
|-
| 7. d7 || ''resigns''
|}

<hex>
R13 C13 Q1 play b2 e6 h5 i10 h10 i11 f10 g7 f7 f8 d9 numbered e8 d7
</hex>

[[Category:Wroclaw_games]]

Computer Hex

2012-11-17T14:55:44Z

Roland Illig: Queenbee is not available anymore

This article enumerates diverse ways to exploit [[Hex]] with a computer.

== AI techniques used in Hex ==

*[[Minimax (computer)|Minimax]] and alpha-beta search were used by [[Queenbee]].
*[[UCT]] is used in MoHex.

== Programs with AI ==

There are several computer programs which play Hex.

=== Available programs ===

{| class="wikitable"
|-
! Program !! Platforms !! Remarks
|-
| [[MoHex]] || Linux || As of 2010, the strongest available Hex program. It uses the UCT-Monte Carlo approach and is developed at the University of Alberta by Philip Henderson, Broderick Arneson and Ryan Hayward.
|-
| [[Wolve]] || Linux || Gold medallist of 2008 Computer Olympiads.
|-
| [[Six]] || Linux, Unix, Windows || by Gábor Melis.
|-
| [[Hexy]] || Windows || The second strongest program available. It was the first program to use virtual connections and was champion of the 5th Computer Olympiad in 2000.
|-
| [[Hexy (iPhone)|Hexy]] || iPhone || Despite using the same name, this program has no relation to [[Hexy]]. It was released in November 2008, offers an AI opponent; the AI appears to be a custom design and hasn't been rated.
|-
| [https://itunes.apple.com/app/id423845369 Hexatious] || iPad, iPhone || Released in August 2009, appears to offer a stronger AI than the iPhone Hexy app (in particular, Hexatious easily beats the other iPhone app in head-to-head competition).
|-
| [https://itunes.apple.com/app/id397349481 Hex Nash] || iPad, iPhone || Released February 2011, no AI but supports online asynchronous play and local play.
|-
| [http://www.mattesmedjan.se/hexilla/ Hexilla] || Java || By Jonatan Rydh, released in October 2009.
|}

=== Unavailable programs ===

* Mongoose by [[Yngvi Björnsson]], [[Ryan Hayward]], Mike Johanson, Morgan Kan, and Nathan Po.
* Queenbee by [[Jack van Rijswijck]] finished second that year.

== Non playing programs ==

=== Front End ===
* [[HexGui]] is a graphical user interface designed by "ab", mostly used as a front end to play against Six. It is possible however to play against other programs that can communicate via [[GTP]]. It can be downloaded on "ab"'s web [http://mgame99.mg.funpic.de/havannah.php page].

=== Reviewing and Editing Programs ===

* [http://canyon23.net/jgame/README_hex.html JHex] by Kevin lets you analyse a game, and databases of games.
* [http://www.drking.plus.com/hexagons/hex/khex.html KHex] by David King is a tool for reviewing games. Very well suited for sharing commented games (it exports games in [[Smart Game Format]]!)

== External link==

=== Articles ===

*Anshelevich, Vadim V. [http://home.earthlink.net/~vanshel/VAnshelevich-ARTINT.pdf A hierarchical approach to computer Hex].
*van Rijswijck, Jack. [http://home.fuse.net/swmeyers/y-hex.pdf Search and evaluation in Hex].
*Rasmussen, Rune K. and Maire, Frederic D. and Hayward, Ross F. (2006) [http://eprints.qut.edu.au/5121/1/5121_1.pdf A Move Generating Algorithm for Hex Solvers].
*Rasmussen, Rune K. (2008) [http://eprints.qut.edu.au/18616/1/01Thesis.pdf Algorithmic approaches for playing and solving Shannon games] (PhD Thesis).

== See also ==
[[History of computer Hex]]

The [[ICGA|International Computer Games Association]] also has some [http://www.cs.unimaas.nl/icga/games/hex/ information on Hex]. They organize an annual [[Computer Olympiad]], which also covers Hex.

[[category:Computer Hex]]

Computer Hex

2012-11-17T14:19:38Z

Roland Illig: /* Available programs */ changed to table layout

This article enumerates diverse ways to exploit [[Hex]] with a computer.

== AI techniques used in Hex ==

*[[Minimax (computer)|Minimax]] and alpha-beta search were used by [[Queenbee]].
*[[UCT]] is used in MoHex.

== Programs with AI ==

There are several computer programs which play Hex.

=== Available programs ===

{| class="wikitable"
|-
! Program !! Platforms !! Remarks
|-
| [[MoHex]] || Linux || As of 2010, the strongest available Hex program. It uses the UCT-Monte Carlo approach and is developed at the University of Alberta by Philip Henderson, Broderick Arneson and Ryan Hayward.
|-
| [[Wolve]] || Linux || Gold medallist of 2008 Computer Olympiads.
|-
| [[Six]] || Linux, Unix, Windows || by Gábor Melis.
|-
| [[Hexy]] || Windows || The second strongest program available. It was the first program to use virtual connections and was champion of the 5th Computer Olympiad in 2000.
|-
| [[Hexy (iPhone)|Hexy]] || iPhone || Despite using the same name, this program has no relation to [[Hexy]]. It was released in November 2008, offers an AI opponent; the AI appears to be a custom design and hasn't been rated.
|-
| [https://itunes.apple.com/app/id423845369 Hexatious] || iPad, iPhone || Released in August 2009, appears to offer a stronger AI than the iPhone Hexy app (in particular, Hexatious easily beats the other iPhone app in head-to-head competition).
|-
| [https://itunes.apple.com/app/id397349481 Hex Nash] || iPad, iPhone || Released February 2011, no AI but supports online asynchronous play and local play.
|-
| [http://www.mattesmedjan.se/hexilla/ Hexilla] || Java || By Jonatan Rydh, released in October 2009.
|}

=== Unavailable programs ===

* [[Mongoose]] by [[Yngvi Björnsson]], [[Ryan Hayward]], Mike Johanson, Morgan Kan, and Nathan Po.

== Non playing programs ==

=== Front End ===
* [[HexGui]] is a graphical user interface designed by "ab", mostly used as a front end to play against Six. It is possible however to play against other programs that can communicate via [[GTP]]. It can be downloaded on "ab"'s web [http://mgame99.mg.funpic.de/havannah.php page].

=== Reviewing and Editing Programs ===

* [http://canyon23.net/jgame/README_hex.html JHex] by Kevin lets you analyse a game, and databases of games.
* [http://www.drking.plus.com/hexagons/hex/khex.html KHex] by David King is a tool for reviewing games. Very well suited for sharing commented games (it exports games in [[Smart Game Format]]!)

== External link==

=== Articles ===

*Anshelevich, Vadim V. [http://home.earthlink.net/~vanshel/VAnshelevich-ARTINT.pdf A hierarchical approach to computer Hex].
*van Rijswijck, Jack. [http://home.fuse.net/swmeyers/y-hex.pdf Search and evaluation in Hex].
*Rasmussen, Rune K. and Maire, Frederic D. and Hayward, Ross F. (2006) [http://eprints.qut.edu.au/5121/1/5121_1.pdf A Move Generating Algorithm for Hex Solvers].
*Rasmussen, Rune K. (2008) [http://eprints.qut.edu.au/18616/1/01Thesis.pdf Algorithmic approaches for playing and solving Shannon games] (PhD Thesis).

== See also ==
[[History of computer Hex]]

The [[ICGA|International Computer Games Association]] also has some [http://www.cs.unimaas.nl/icga/games/hex/ information on Hex]. They organize an annual [[Computer Olympiad]], which also covers Hex.

[[category:Computer Hex]]

Basic (strategy guide)

2012-11-12T05:22:36Z

Roland Illig: /* Blocking moves */ changed markup

''Adapted with permission from Glenn C. Rhoads strategy guide.''

== Rules of Hex ==
''(See also the article [[Rules]])''

[[Hex]] is a two player [[Wikipedia:Board_game|board game]] played on an ''n × n'' grid of [[hexagon]]s.

A [[Move|turn]] in Hex consists of placing a [[piece]] of your [[color]] on a hexagon. The [[first player]]'s goal is to form an unbroken [[chain]] of hexes of his color that [[connection|connects]] the top to the bottom while the [[second player]] tries to form an unbroken chain connecting the left and right sides.

[[Swap rule]]: After the initial play only, the second player has the option of either responding with his turn or swapping sides taking the initial play as his first turn.

Without the swap rule, the first player has a strong [[advantage]]. The swap rule equalizes this advantage by forcing the first player to make a move that leads to a roughly equal game. If the first player makes a very strong opening move, the second player will swap sides and start with an advantage. If the first player makes a very weak opening move, the second player won't swap and again will start with an advantage.

== Basic strategy ==

Notation: the [[row]]s of the board are [[coordinates|indexed]] by numbers and the [[column]]s are indexed by letters. Individual hexes are referred to by listing the column index followed by the row index; e.g. hex c2 is the one in column c row 2. Here at [[HexWiki:About|HexWiki]], red pieces belong to the [[vertical (player)|"vertical" player]], and blue pieces belong to the [[horizontal (player)|"horizontal" player]]. An empty 4 × 4 board looks like follows.

<hex>R4 C4 Q1</hex>

=== The two-bridge ===
''(See also the article [[Bridge]])''

The formation consisting of two pieces that are non-adjacent but have two empty neighboring hexes in common is referred to as a [[bridge|two-bridge]]; e.g. the pieces on b2 and c3, and the empty hexes b3 and c2 in the following diagram form a two-bridge.

<hex>R4 C4 Q1 Vb2 Vc3</hex>

The two pieces are almost as strongly connected as a solid chain from b2 to c3. The opponent can attempt to break this connection only by playing a piece at either b3 or c2, and no matter which one the opponent plays, you can play the other and restore the link. For most purposes you can think of the two-bridge pieces as already being connected. By connecting pieces via two-bridges, you can spread across the board twice as fast as by playing adjacent hexes.

{| border="0" cellpadding="2"
| <hex>R7 C7 Q1 Ve1 Ve2 Vd3</hex> || <hex>R7 C7 Q1 Ve2 Vd4 Vc6</hex>
|-
| <center>''Expanding by adjacent moves''</center> || <center>''Expanding by two-chains''</center>
|}

Considered in isolation the pieces in a two-chain are [[strong connection|connected]] but sometimes a two-chain can be broken by playing a piece in the middle of a two-chain that contains some other [[threat]] that must be immediately answered. After the opponent answers the threat, you can then play in the other hex in the two-chain breaking the connection.

Also, playing in the middle of a two-chain can be a good play even when the opponent should and does respond by saving the link. The reason being that the piece played may be useful later.

=== Blocking moves ===

When you have no pieces in the area, it is usually best to start blocking broadly close to at least one of your edges and not too close to the opponent's piece.

If your blocking move has too little influence on both your edges, then the opponent has at least two good zones of the board that are worth trying, one for each side. For example, compare the situation for blue in these two cases.

<hex>R11 C11 labels play numbered f6 e9 g8 f7 h6 h9 c9</hex>

In this case, the blue initial pieces (E9 and F7) have very little influence on both blue's edges and thus don't provide any immediate threat on bottom. Blue has no choice but to play D8, which however is still far from being connected to any blue's edge.

<hex>R11 C11 labels play numbered f6 f8 e8 f7 e7 d3</hex>

This position on the other hand is quite more tricky for red to play correctly than the first. Blue is still too much focused (unavoidably, given the weak position) on bottom but, after having obtained a reasonable influence on the right side, he can now concentrate his efforts on the left side of the board.

If you block too close to the opponent, then he can simply flow around the attempted block. For example, suppose you are trying to stop the vertical player from connecting to the bottom in the following diagram.

<hex>R11 C11 labels red h1 h2 h3 g4 g5 g6</hex>

If you try to block by playing adjacent to the [[leading piece]], say by playing at g7, then the vertical player can simply step around it at f7 (see diagram below). Then the attempted block at say e8, could similarly be met by playing at f8. Obviously, you are not making any progress here.

<hex>R11 C11 labels red h1 h2 h3 g4 g5 g6 blue play numbered g7 f7 e8 f8</hex>

Another try from the original position would be to block at a two-chain distance away at f8 (see diagram below). This is better than the [[adjacent block]] but sometimes the opponent can flow around this too by two-chaining at an angle — e.g. by playing h7 in response to f8. (h7 should be met by either h8 or g9.)

<hex>R11 C11 labels red h1 h2 h3 g4 g5 g6 blue play numbered f8 h7</hex>

Another possibility is to combine the above two ideas by first doing an adjacent block at g7 and then if the vertical player responds with f7, you block at a two-chain distance away at e9. Then your opponent cannot two-chain towards the right because of the initial g7 piece.

<hex>R11 C11 labels red h1 h2 h3 g4 g5 g6 blue play numbered g7 f7 e9</hex>

A good block in the original position is to block at one hex farther back than the two-chain block at either e9 or f9 (sometimes this is referred to as the [[classic block]]). For example suppose H blocks at f9 (see diagram below). Two-chaining to f8 is met by e9. Two-chaining to the lower right (h7) is met by h8 and two-chaining towards the lower-left (e7) is met by d8. By blocking at a distance, you have a move or two before the advancing head reaches the blocking pieces. Note that when the board size is smaller than 11 × 11, then the classic block is much less useful due to the lack of space.

<hex>R11 C11 labels red h1 h2 h3 g4 g5 g6 blue play numbered f9 f8 e9 h7 h8 e7 d8</hex>

Suppose Red opens with G4 and Blue plays E6 yielding the following.

<hex>R10 C10 labels play numbered g4 e6</hex>

Blue's play is what I call an '''indirect block'''; it does not directly block the Red G4 from the bottom rather it threatens to block it on the next move. Red
cannot afford to ignore this threat. If for example Red plays G3, Blue responds
with G5 completely cutting off Red's pieces from the bottom.

<hex>R10 C10 labels play g4 e6 numbered g3 g5</hex>

Instead Red can play towards the bottom with F6 and blue can complete his block
by playing E8 for example.

<hex>R10 C10 labels play g4 e6 numbered f6 e8</hex>

'''Blocking Summation''' 
The most important thing for a beginner to do is to avoid the mistake of repeatedly trying to block by playing adjacent to the head of the chain as shown in the first example. Playing ahead of the chain as in the classic block gives you a move or two to place your pieces before the advancing chain meets your pieces.

== General principles ==

=== A position is only as good as the weakest link ===
''(See also the page [[Weakest link]])''

Thus, with each move you should attempt to either improve your weakest link or make your opponent's weakest link even weaker. A move which does both is a strong move. For example, in the position below the hex f6 is the weakest point in the Red's best connection across the board. It is also the weakest link in the Blue's best connection across the board. Thus, the player whose turn it is to move would be wise to play at f6. In fact, whoever plays next has a forced win after playing f6.

<hex>R11 C11 Q1 Vh2 Vg4 Hb5 Hh5 Hc6 Sf6 Hi6 Ve8 Vd10</hex>

=== Offense equals defense ===
''(See also the page [[Offense equals defense]])''

In Hex, good [[offense]] and good [[defense]] are entirely equivalent. If you complete a connection between your sides, then your opponent is prevented from completing theirs. Conversely, if your opponent is prevented from completing a connection, then you must have completed yours (draws cannot occur in Hex). Furthermore, the only way to complete a connection is to prevent your opponent from making a connection and the only way to prevent your opponent from connecting is to complete your connection. In a very real sense, you don't have to worry about whether you should play offensively or defensively since they are the same. The critical point to remember is that unless you are making a sequence of [[forcing move|forcing plays]], it is generally easier to think in terms of good defense than good offense regardless of whether you are currently winning or losing. This point about thinking defensively should frequently be used with point 3.1 above. Often it is best to look for the connection that your opponent is going to have the toughest time making (point 3.1 above). For example, suppose that my opponent's most difficult connection to complete looks like the connection to the right edge of the board. Then I'll look for good defensive moves that make it even more difficult for my opponent to connect up to the right edge.

=== Momentum ===
''(See also the page [[Momentum]])''

The player who is dictating the play is said to have the '''momentum'''. Alternatively, the momentum is against the player who is being forced to respond to the opponent. The player with the momentum usually has the advantage and this advantage is often decisive. You should generally not hand over the momentum to the opponent unless you have a very good reason for doing so. In well played close matches, the momentum often swings between the two players with each move.

=== Multiple threats per move ===
''(See also the page [[Multiple threats]])''

Whenever possible, a player should make each move achieve at least two different goals or threats. Moves that contain only a single threat are generally not hard to meet. If a move contains multiple threats, the opponent may not be able to stop all the threats with a single move.

=== The center ===

The central region of the board is strategically the most important area. From the center, connections can spread out in many directions giving you more flexibility and options than starting from an edge. Furthermore, centrally played pieces are more nearly equidistant from both of your edges — this is related to point 3.1 about improving your weakest link. The greater distance apart two pieces are, the harder they are to connect up, i.e. their potential link is weaker.

== The opening ==

Without the [[swap rule]], the initial move would be easy. Playing in the [[center hex]] is the strongest opening move. The weakest opening move is to play in one of the acute corners (a1 and the opposite corner) and is one of only two opening moves that are a proven loss (without the swap option). The other is right next to it at b1. Suppose the [[red|vertical player]] moves first. Which opening moves should you swap and which should you not swap? The following is my personal rules for the 10 × 10 board.

=== 10 × 10 swap rules ===

# Don't swap any of Vertical's border row moves except for the obtuse corner.
# Don't swap a2, or b2 (nor the symmetrically equivalents i9 and j9).
# Swap all other initial moves.

Note: the possible theoretical exceptions to these rules are the opening moves a2, b2, c2 and a3 (and their symmetric equivalents). The winning/losing margin with these moves is so razor thin that nobody has been able to determine with any confidence whether these moves should theoretically be swapped or not.

=== Good opening moves on the 10 × 10 ===

The best opening moves against an experienced player are the [[border hex]]es (except don't open a1!) and b2 and c2. b2—d2 are probably the only good non-border moves against an experienced player (b2 is essentially equivalent to the move a2 which is a popular opening choice and there is almost no difference between b2 and c2). Against lesser experienced players you can play something stronger such as one out from the obtuse corner (b9/i2) because they might not realize its strength and even if they do swap, they may not be capable of taking advantage of it anyway.

a2/b2 and a3 both lead to a balanced game and seem to be the most popular choices. Except for games between expert players, you can safely play either side of a2/b2 or a3 and have an equal chance of winning (and similarly for other opening plays). Also some variation in opening play is generally good. Varying your opening is the first thing to try against an opponent that seems to have your number. Sometimes you can find a weakness in a player's personal swap rules by trying out different openings.

=== The second and third moves ===

A very common but not the only good response to a border opening is to play in one of the two central hexes e6 or f5. The third move in response to a central reply should be a blocking move on the side of e6/f5 that is farthest from the edge. e6 is one hex closer to the left edge and f5 is one hex closer to the right edge. In accordance with the principle of exploiting your opponent's weakest link, you should therefore block f5 on the left and e6 on the right. Thus, a typical opening sequence would be a2, ''swap'', f5, c6. In my opinion, the strength of the central response is overrated; practically any move that is not in one of the 3 rows closest to your border rows and that is also not too close to the opponent's border, is a near equally good response. If there is any difference in strength, it is for all practical purposes non-existent.

Update: The top players now show a definite preference for non-central responses. On the 13 by 13 game at littlegolem, most of the top players prefer to respond to a border opening with something on the 5'th row from one of their edges over the central response G7. I.e. the consensus is that responding to a border opening by playing in the center is NOT the best reply!

== Board size ==

Hex can be played on any size [[board]]. If the board is [[Small boards|too small]], the game becomes trivial and uninteresting. The "standard" size at the online site [[PlaySite]] is 10 × 10 but in my opinion, this is just a little too small and the "standard" size should really be 11 × 11 (11 × 11 is the standard size at [[pbmserv|the PBM play by email site]]). Some experienced players prefer a larger board such as 14 × 14 or 17 × 17. As the board size gets larger and larger, the game becomes more subtle and strategic. Hex is actually of comparable complexity and depth to the oriental board game [[Go]] played on the same size board (many Go players consider Go to be the deepest and most complex perfect information strategy game ever invented).

A typical hex game fills about one-third of the board. We can use this to get a good estimate of the average number of moves for any board size.

* 10 × 10: 16 moves per side
* 11 × 11: 20 moves per side
* 14 × 14: 28 moves per side
* 17 × 17: 48 moves per side
* 19 × 19: 60 moves per side (this is the standard size in Go)

One of the pleasant aspects of Hex is that games generally do not last as long as in other strategy games of comparable complexity (e.g. Go typically lasts around 140 moves per side). The 11 × 11 game is very good and takes only about 20 moves per side. For those wanting a more complex game, the 14 × 14 game provides it without having the length of the game blow up to marathon proportions.

== Reference bibliography ==

''Hex Strategy: Making the Right Connections'', by Cameron Browne, A.K. Peters Ltd., 2001. — The strategy part of this book is generally very sound. The primary exception is that the suggested opening swap rules are not correct at all.

== See also ==
* [[Intermediate (strategy guide)]]
* [[Advanced (strategy guide)]]

[[category:opening]]
[[category:Basic Strategy]]

A3 escape trick

2012-11-12T04:58:31Z

Roland Illig: changed hex markup

{{wrongtitle|title=a3 escape trick}}

The term '''a3 escape trick''' denotes the fact that though a red piece on a3 is not part of an [[edge template]] to the [[Top edge|top]], it can still be useful as a [[ladder escape]], when handled correctly.

== Example ==

Consider the following position:

<hex>
R8 C8 labels
blue g2 h2 e4 e5
red a3 g3 f5 e6
</hex>

The a3 escape trick consists of laddering to e3 (making a three-hex gap between the ladder and a3) and then connecting a3 through a [[bridge]]:

<hex>
R8 C8 labels
blue g2 h2 e4 e5
red a3 g3 f5 e6
play numbered f3 f2 e3 e2 b4
</hex>

Blue's only working response is d3, to which Red responds with another bridge:

<hex>
R8 C8 labels
blue g2 h2 e4 e5
red a3 g3 f5 e6
play f3 f2 e3 e2 b4
numbered d3 c5
star d4 d6
</hex>

No matter what Blue plays Red can either connect with the ladder or directly to the bottom.

Blue can also play c3 instead of d3 but the outcome is the same.

This escape does not always work, depending on the [[Board size|size of the board]] and the pieces already on it.

== See also ==

* [[a3 opening]]
* [[Ladder]]s

[[category:ladder]]

A1 opening

2012-11-12T04:30:20Z

Roland Illig: replaced image with hex markup

{{wrongtitle|title=a1 opening}}

The '''a1 opening''' (in the acute corner) is one of only two openings known to be defeatable. The other is [[B1 opening|b1]].

(This does not mean that these are the worst possible opening moves. Compare with the diagrams on [http://www.cs.ualberta.ca/~queenbee/openings.html the openings page at the queenbee site])

Like the proof that Hex is a win for the first player, the proof that A1 loses is non-constructive: Although we know that it exists, the winning strategy has not been found for regular sized Hex boards.

Due to the symmetry of the Hex board, the same is true of the opposite hexes, but they are not usually referred to explicitly because their coordinate depends on the size of the board.

<hex>
R7 C7 border
play numbered a1
</hex>

== Sketch for proof ==

Let's suppose a1 is a winning first move for Red. There exists a [[winning strategy]] for Red beginning with 1.a1.

Blue answers a2, this move makes Red's move useless as b1 does not need a1 to connect to top edge. Blue can now pretend to be the first player.

Every winning connection that would have used the hex a1 is a winning connection here too, thanks to a2. Hence Blue can use Red's winning strategy and win too.

This is absurd and so there is no winning strategy beginning by a1. Therefore 1.a1 is a losing move (because there is no draw possible).

<hex>
R7 C7 border
play numbered a1 a2
</hex>

== a2 has been proved a losing answer ==
[http://hex.kosmanor.com/hex/b1loses.html A sketch of the proof on kosmanor page]

== References ==
References for proofs can be found on the [http://hex.kosmanor.com/hex/theory.html Hex Theory] page.

[[Category: Opening]]
[[Category: Theory]]

Attack zone

2012-11-12T04:13:27Z

Roland Illig: Removed dead links, changed markup, added category

''Definitions'': A cell is '''reachable''' from an edge if a straight line of diagonal [[bridge]] jumps can be made between the cell and the edge:

<hex>R4 C8 Vg1 Se2 Sc3 Pf1 Pf2 Pd2 Pd3 Pb4 Pc4</hex>

A cell is '''doubly reachable''' if diagonals can be made in both directions:

<hex>R4 C8 Vf1 Sd2 Sb3 Sg2 Sh3</hex>

The '''Attack zone''' for a certain edge consists of all cells which are doubly reachable from that edge.

<hex>R8 C8 plus a8 b8 c8 d8 e8 f8 g8 h8 b7 c7 d7 e7 f7 g7 h7 d6 e6 f6 g6 f5</hex>

[[Category:Definition]]

Ladder handling

2012-11-12T03:12:23Z

Roland Illig: Removed dead links

In a [[ladder]] situation, the players have two different roles: The player who tries to connect to the edge is the attacker, and the player who tries to prevent the other from connecting is called the defender. Here is an example where Red is the attacker and Blue is the defender, with Blue to move.

<hex>R4 C8 Vb2 Vc2 Vd2 Ve2 Ha3 Hb3 Hc3 Hd3</hex>

Generally the attacker has the [[momentum]]. The defender's moves are usually forced; he has to defend or else the attacker will connect.

== Defending ==

The defender has two options: he can push or he can yield. '''Pushing''' means to play a move on the same row as the earlier moves, while '''yielding''' means to allow the attacker to get one row closer to the edge. The two possibilities are marked with a star in this diagram:

<hex>R4 C8 Vb2 Vc2 Vd2 Ve2 Ha3 Hb3 Hc3 Hd3 Se3 Se4</hex>

It is usually best to continue pushing until the attacker does something else, but occasionally it is essential to yield in order to avoid one of Red's [[outpost]]s, as in the following diagram:

<hex>R4 C9 Vb2 Vc2 Vd2 Ve2 Ha3 Hb3 Hc3 Hd3 Hf1 Vg1 Se3 Se4</hex>

If Blue pushes in this diagram, Red will be able to connect to the bottom. If Blue yields instead, Red won't be able to. It is important for Blue to yield at precisely the right moment. Had he done it one move earlier, Red would have connected to the bottom.

== Attacking ==

Red usually has three options: he can push, break or jump. The possibilities are shown in the following diagram:

<hex>R5 C10 Vb3 Vc3 Vd3 Ha4 Hb4 Hc4 Hd4 Se3 Sf3 Sf2</hex>

* '''Pushing''' means to continue with adjacent moves on the same row.
* '''Breaking''' means to play on the same row, but skipping one hex.
* '''Jumping''' means to go one row further away from the edge. Note that jumping is a move similar (symmetric) to the defender´s yielding; however jumping is usually an offensive move, while yielding is very |defensive, hence they have different words.

Jumping is used when the attacker has a ladder escape but needs to get further from the edge to use it. Here is a standard example:

<hex>R5 C10 Vb4 Vc4 Vd4 Ha5 Hb5 Hc5 Hd5 Vg1 Vh1 Sf3 Ph3</hex>

Red first jumps to (*). If Blue makes the standard response, Red's next move is (+), making a [[connection]] to the bottom.

[[category:ladder]]

Ladder handling

2012-11-12T03:01:37Z

Roland Illig: Don't use unnecessary words

In a [[ladder]] situation, the [[player]]s have two different roles: The player who tries to connect to the edge is the [[attacker]], and the player who tries to prevent the other from connecting is called the [[defender]]. Here is an example where [[Red (player)|Red]] is the attacker and [[Blue (player)|Blue]] is the defender, with Blue to move.

<hex>R4 C8 Vb2 Vc2 Vd2 Ve2 Ha3 Hb3 Hc3 Hd3</hex>

Generally the attacker has the [[momentum]]. The defender's moves are usually [[Forced move|forced]]; he has to defend or else the attacker will connect.

== Defending ==

The defender has two options: he can [[Pushing|push]] or he can [[Yielding|yield]]. '''Pushing''' means to play a move on the same row as the earlier moves, while '''yielding''' means to allow the attacker to get one row closer to the edge. The two possibilities are marked with a star in this diagram:

<hex>R4 C8 Vb2 Vc2 Vd2 Ve2 Ha3 Hb3 Hc3 Hd3 Se3 Se4</hex>

It is usually best to continue pushing until the attacker does something else, but occasionally it is essential to yield in order to avoid one of Red's [[outposts]], as in the following diagram:

<hex>R4 C9 Vb2 Vc2 Vd2 Ve2 Ha3 Hb3 Hc3 Hd3 Hf1 Vg1 Se3 Se4</hex>

If Blue pushes in this diagram, Red will be able to connect to the [[Bottom edge|bottom]]. If Blue yields instead, Red won't be able to. It is important for Blue to yield at precisely the right moment. Had he done it one move earlier, Red would have connected to the bottom.

== Attacking ==

Red usually has three options: he can [[Pushing|push]], [[Breaking|break]] or [[Jumping|jump]]. The possibilities are shown in the following diagram:

<hex>R5 C10 Vb3 Vc3 Vd3 Ha4 Hb4 Hc4 Hd4 Se3 Sf3 Sf2</hex>

'''Pushing''' means to continue with adjacent moves on the same row. '''Breaking''' means to play on the same row, but skipping one [[Hex (board element)|hex]]. '''Jumping''' means to go one row further away from the edge. Note that jumping is a move similar (symmetric) to the defender´s yielding; however jumping is usually an [[Offense|offensive]] move, while yielding is very [[Defense|defensive]], hence they have different words.

Jumping is used when the attacker has a ladder escape but needs to get further from the edge to use it. Here is a standard example:

<hex>R5 C10 Vb4 Vc4 Vd4 Ha5 Hb5 Hc5 Hd5 Vg1 Vh1 Sf3 Ph3</hex>

Red first jumps to (*). If Blue makes the [[standard response]], Red's next move is (+), making a [[connection]] to the [[Bottom edge|bottom]].

[[category:ladder]]

Help:Hex

2012-11-04T14:37:08Z

Roland Illig: /* Setting up a certain position and some moves */

This is the documentation for the MediaWiki plug-in for drawing Hex diagrams.

== Syntax ==

Hex diagrams are specified using the <tt><hex></tt>...<tt></hex></tt> tag.
Inside this tag, a series of words describes the diagram itself.
The first letter of each word is called the ''command'', and the remaining letters are its ''arguments''.
There are commands for specifying the board size and for putting stones on the board.

=== Examples ===

* <tt><hex> R5 C5 </hex></tt> draws an empty hex board with 5 rows and 5 columns.

== Setting up the board ==

Before doing anything else, you have to say how large the board is. Each board has a number of rows (which go horizontally) and columns (which go vertically). In addition to that, you can say that you want the rows and colums labelled with their letters and numbers.

The commands for setting up the board all take a single numeric argument. The commands are:

* '''R''': Specifies the number of rows of the board.
* '''C''': Specifies the number of columns of the board.
* '''Q''': Specifies whether the coordinates should be printed next to the board. Zero means ''no'', any other number means ''yes''. By default, they are not shown.

=== Examples ===

* '''R5''' sets the number of rows to 5.
* '''Q1''' makes the coordinates appear next to the board.
* '''Q0''' explicitly makes the coordinates disappear.
* '''<nowiki><hex>R5 C5 Q1</hex></nowiki>''' creates a board with five rows and five colums, which are all labelled.

<hex>R5 C5 Q1</hex>

== Setting up single stones ==

The commands for setting up stones all take a coordinate as their argument. Coordinates are written in the form ''f7'', where ''f'' is the column and ''7'' is the row.

The commands are:
* '''B''' for a blue stone.
* '''R''' for a red stone.
* '''H''' for a horizontal stone (equivalent to '''B''').
* '''V''' for a vertical stone (equivalent to '''R''').
* '''S''' or '''*''' for a star.
* '''P''' or '''+''' for a plus.

When you want to add move numbers, put a single digit (0-9) between the command and the coordinate,
for example '''R5e4''' when Red puts his fifth move onto e4.

It is also possible to link stones to any other wiki page. For that, use the form '''<nowiki>[[</nowiki>''Link_target''|''Word'']]''', where ''Word'' is used to setup the stone and ''Link_target'' is where you want to arrive when you click the link.

=== Examples ===

* '''Ba4''' puts a blue stone ('''B''') in the first column ('''a''') of the fourth row ('''4''').
* '''R7b1''' puts a red stone ('''R''') in the second column ('''b''') of the first row ('''1''') and labels it with a seven ('''7''').
* '''<nowiki>[[</nowiki>#Setting_up_single_stones|Ba5]]''' puts a blue stone on the board and links it to the section called ''Setting up single stones'' on the same page. Note that you cannot use space characters in the link.

<hex>
R5 C5 Q1
Ba4 R7b1 [[#Setting_up_single_stones|Ba5]]
</hex>

== Automatically numbered moves ==

There is a special command ('''M''') for setting up numbered sequences of moves. The first of these moves is for Red and is labelled with a ''1''. After each '''M''' command, the color changes and the move number is increased automatically.

If you want to enter a sequence of moves that starts with a blue move, write '''MB'''. This changes the color without affecting the move number or the stones on the board.

When you want to show a complete game, it can be annoying to replace the '''H'''... and '''V'''... commands with '''M'''. For this reason, there is another feature, which automatically numbers the following stones. It is switched on with '''N:on''' and off with (you guessed it) '''N:off'''.

=== Limitations ===
Currently, the number of moves is restricted to 10, but this may be extended if there is the need for it. But before you request this change, please ask yourself whether you really need it. Ten moves is a lot, and especially when analyzing games, it would be easier for the reader if you split the moves into several diagrams.

=== Examples ===
* '''MR Ma1 Ma2 Ma3 Mb4''' is a sequence of four moves, starting with a red ''1''.
* '''M5c1 Mc2 Mc3''' are three moves, starting with a red ''5''.
* '''MB Me1 Me2 Me3''' are three moves, starting with a blue ''1''.
* '''N:on Rg1 Bg7 N:off Rg4''' results in two numbered moves on g1 and g7, and one unnumbered move at g4.

<hex>
R11 C11 Q1
MR Ma1 Ma2 Ma3 Ma4
M5c1 Mc2 Mc3
M0e1
MB Me1 Me2 Me3
N:on Rg1 Bg7 N:off Rg4
</hex>

== Setting up a certain position and some moves ==

When you set up a position there are two common cases: replaying a game, or setting up an isolated position. These cases can be written easily using the following ''setup modes'':

* <tt>play</tt> is used for playing mode. The color of the stones alternates between red and blue.
* <tt>red</tt> is used for putting red stones on the board. When switching to <tt>play</tt> mode later, the first move will be red's.
* <tt>blue</tt> is used for putting blue stones on the board. When switching to <tt>play</tt> mode later, the first move will be blue's.

All coordinates that follow the setup mode are processed according to that mode.
The following diagram shows how the setup modes can be used.

<pre>
<hex>
R5 C9 labels border
play a1 a2 a3 a4
red numbered c1 c2 c3 c4 unnumbered
blue e1 e2 e3 e4
play numbered g1 g2 g3 g4 unnumbered
red play i1 i2 i3 i4
</hex>
</pre>

<hex>
R5 C9 labels border
play a1 a2 a3 a4
red numbered c1 c2 c3 c4 unnumbered
blue e1 e2 e3 e4
play numbered g1 g2 g3 g4 unnumbered
red play i1 i2 i3 i4
</hex>

Note:
* The <tt>play</tt> mode keeps the color from before. So when you write <tt>blue</tt> (as for e1, e2, e3, e4) and then <tt>play</tt> (as for g1), the first move is blue.
* To change the color of the next move you can write <tt>red</tt> <tt>play</tt>, as shown for i1.
* The setup modes can be mixed freely with <tt>numbered</tt> and <tt>unnumbered</tt>.
* The setup modes are useful for setting up diagrams from game records since you don't need to write the color in front of every move. Just the coordinate is enough.
* The setup modes <tt>red</tt> and <tt>blue</tt> are also useful for setting up individual positions.

== Setting up a whole line at once ==

In many cases, there are many stones on the board, and it would be annoying to write one word for each stone.
For this reason, there exists a short-cut for drawing a complete line. If a word starts with a number, followed by a colon (:) and a list of cell contents, the whole line can be drawn with only one command. The valid types of cell contents are:
* '''R''' or '''V''' for red stones,
* '''B''' or '''H''' for blue stones,
* '''*''' or '''S''' for stars,
* '''+''' or '''P''' for plus,
* '''_''' for an empty cell.

=== Limitations ===
* Stones with numbers cannot be put using this command. Instead, use the commands for putting a single stone or for putting a series of moves.

=== Examples ===
* '''3:__BBRRBBRR__*''' sets up the first 13 stones of the third row. The first two are empty, the next two are blue, and so on.

<hex>
R3 C13 Q1
3:__BBRRBBRR__*
</hex>

== Formatting diagrams usefully ==

Depending on the situation and the intent of a diagram, it may be formatted in different styles. Large diagrams should be distributed over several lines, to make editing and reading easier. The suggested format is:
# Board size and coordinates,
# Setup stones: One line per color,
# The moves in the order they are played.

See the diagrams below for examples.

== Examples for Complete Diagrams ==

=== A simple board with stones in all four corners ===

<hex>
R5 C5 Q1
Ra1 Re5
Be1 Ba5
</hex>

And the same with stones that are linked to other pages.

<hex>
R5 C5 Q1
[[Red|Ra1]] [[Red|Re5]]
[[Blue|Be1]] [[Blue|Ba5]]
</hex>

=== Numbered moves ===

<hex>
R5 C5 Q1
Mc3 Ma3 Me3 Mb2 Md4
</hex>

=== Border ===
You can draw a colored border around the diagram by giving the command <tt>B:on</tt>.

<hex>
R5 C5 Q1 B:on
Ma1 Mb2 Mc3 Md4 Me5
</hex>

=== All possible fields ===

<hex>
Q1 C11 R4
Ra1 R1b1 R2c1 R3d1 R4e1 R5f1 R6g1 R7h1 R8i1 R9j1 R0k1
Ba2 B1b2 B2c2 B3d2 B4e2 B5f2 B6g2 B7h2 B8i2 B9j2 B0k2
Sa3 *b3 Pd3 +e3
Ma4 Mb4 Mc4 Md4 Me4 Mf4 Mg4 Mh4 Mi4 Mj4 Mk4
</hex>

== Source code ==

The full source code of the plug-in is available [http://www.hexwiki.org/hex/ here].

Help:Hex

2012-11-04T14:32:40Z

Roland Illig: /* Setting up a certain position and some moves */ changed the syntax to "common words" instead of cryptic abbreviations

This is the documentation for the MediaWiki plug-in for drawing Hex diagrams.

== Syntax ==

Hex diagrams are specified using the <tt><hex></tt>...<tt></hex></tt> tag.
Inside this tag, a series of words describes the diagram itself.
The first letter of each word is called the ''command'', and the remaining letters are its ''arguments''.
There are commands for specifying the board size and for putting stones on the board.

=== Examples ===

* <tt><hex> R5 C5 </hex></tt> draws an empty hex board with 5 rows and 5 columns.

== Setting up the board ==

Before doing anything else, you have to say how large the board is. Each board has a number of rows (which go horizontally) and columns (which go vertically). In addition to that, you can say that you want the rows and colums labelled with their letters and numbers.

The commands for setting up the board all take a single numeric argument. The commands are:

* '''R''': Specifies the number of rows of the board.
* '''C''': Specifies the number of columns of the board.
* '''Q''': Specifies whether the coordinates should be printed next to the board. Zero means ''no'', any other number means ''yes''. By default, they are not shown.

=== Examples ===

* '''R5''' sets the number of rows to 5.
* '''Q1''' makes the coordinates appear next to the board.
* '''Q0''' explicitly makes the coordinates disappear.
* '''<nowiki><hex>R5 C5 Q1</hex></nowiki>''' creates a board with five rows and five colums, which are all labelled.

<hex>R5 C5 Q1</hex>

== Setting up single stones ==

The commands for setting up stones all take a coordinate as their argument. Coordinates are written in the form ''f7'', where ''f'' is the column and ''7'' is the row.

The commands are:
* '''B''' for a blue stone.
* '''R''' for a red stone.
* '''H''' for a horizontal stone (equivalent to '''B''').
* '''V''' for a vertical stone (equivalent to '''R''').
* '''S''' or '''*''' for a star.
* '''P''' or '''+''' for a plus.

When you want to add move numbers, put a single digit (0-9) between the command and the coordinate,
for example '''R5e4''' when Red puts his fifth move onto e4.

It is also possible to link stones to any other wiki page. For that, use the form '''<nowiki>[[</nowiki>''Link_target''|''Word'']]''', where ''Word'' is used to setup the stone and ''Link_target'' is where you want to arrive when you click the link.

=== Examples ===

* '''Ba4''' puts a blue stone ('''B''') in the first column ('''a''') of the fourth row ('''4''').
* '''R7b1''' puts a red stone ('''R''') in the second column ('''b''') of the first row ('''1''') and labels it with a seven ('''7''').
* '''<nowiki>[[</nowiki>#Setting_up_single_stones|Ba5]]''' puts a blue stone on the board and links it to the section called ''Setting up single stones'' on the same page. Note that you cannot use space characters in the link.

<hex>
R5 C5 Q1
Ba4 R7b1 [[#Setting_up_single_stones|Ba5]]
</hex>

== Automatically numbered moves ==

There is a special command ('''M''') for setting up numbered sequences of moves. The first of these moves is for Red and is labelled with a ''1''. After each '''M''' command, the color changes and the move number is increased automatically.

If you want to enter a sequence of moves that starts with a blue move, write '''MB'''. This changes the color without affecting the move number or the stones on the board.

When you want to show a complete game, it can be annoying to replace the '''H'''... and '''V'''... commands with '''M'''. For this reason, there is another feature, which automatically numbers the following stones. It is switched on with '''N:on''' and off with (you guessed it) '''N:off'''.

=== Limitations ===
Currently, the number of moves is restricted to 10, but this may be extended if there is the need for it. But before you request this change, please ask yourself whether you really need it. Ten moves is a lot, and especially when analyzing games, it would be easier for the reader if you split the moves into several diagrams.

=== Examples ===
* '''MR Ma1 Ma2 Ma3 Mb4''' is a sequence of four moves, starting with a red ''1''.
* '''M5c1 Mc2 Mc3''' are three moves, starting with a red ''5''.
* '''MB Me1 Me2 Me3''' are three moves, starting with a blue ''1''.
* '''N:on Rg1 Bg7 N:off Rg4''' results in two numbered moves on g1 and g7, and one unnumbered move at g4.

<hex>
R11 C11 Q1
MR Ma1 Ma2 Ma3 Ma4
M5c1 Mc2 Mc3
M0e1
MB Me1 Me2 Me3
N:on Rg1 Bg7 N:off Rg4
</hex>

== Setting up a certain position and some moves ==

When you set up a position there are two common cases: replaying a game, or setting up an isolated position. These cases can be written easily using the following ''setup modes'':

* <tt>play</tt> is used for playing mode. The color of the stones alternates between red and blue.
* <tt>red</tt> is used for putting red stones on the board. When switching to <tt>play</tt> mode later, the first move will be red's.
* <tt>blue</tt> is used for putting blue stones on the board. When switching to <tt>play</tt> mode later, the first move will be blue's.

All coordinates that follow the setup mode are processed according to that mode.
The following diagram shows how the setup modes can be used.

<pre>
<hex>
R5 C9 labels borders
play a1 a2 a3 a4
red numbered c1 c2 c3 c4 unnumbered
blue e1 e2 e3 e4
play numbered g1 g2 g3 g4 unnumbered
red play i1 i2 i3 i4
</hex>
</pre>

<hex>
R5 C9 labels borders
play a1 a2 a3 a4
red numbered c1 c2 c3 c4 unnumbered
blue e1 e2 e3 e4
play numbered g1 g2 g3 g4 unnumbered
red play i1 i2 i3 i4
</hex>

Note:
* The <tt>play</tt> mode keeps the color from before. So when you write <tt>blue</tt> (as for e1, e2, e3, e4) and then <tt>play</tt> (as for g1), the first move is blue.
* To change the color of the next move you can write <tt>red</tt> <tt>play</tt>, as shown for i1.
* The setup modes can be mixed freely with <tt>numbered</tt> and <tt>unnumbered</tt>.
* The setup modes are useful for setting up diagrams from game records since you don't need to write the color in front of every move. Just the coordinate is enough.
* The setup modes <tt>red</tt> and <tt>blue</tt> are also useful for setting up individual positions.

== Setting up a whole line at once ==

In many cases, there are many stones on the board, and it would be annoying to write one word for each stone.
For this reason, there exists a short-cut for drawing a complete line. If a word starts with a number, followed by a colon (:) and a list of cell contents, the whole line can be drawn with only one command. The valid types of cell contents are:
* '''R''' or '''V''' for red stones,
* '''B''' or '''H''' for blue stones,
* '''*''' or '''S''' for stars,
* '''+''' or '''P''' for plus,
* '''_''' for an empty cell.

=== Limitations ===
* Stones with numbers cannot be put using this command. Instead, use the commands for putting a single stone or for putting a series of moves.

=== Examples ===
* '''3:__BBRRBBRR__*''' sets up the first 13 stones of the third row. The first two are empty, the next two are blue, and so on.

<hex>
R3 C13 Q1
3:__BBRRBBRR__*
</hex>

== Formatting diagrams usefully ==

Depending on the situation and the intent of a diagram, it may be formatted in different styles. Large diagrams should be distributed over several lines, to make editing and reading easier. The suggested format is:
# Board size and coordinates,
# Setup stones: One line per color,
# The moves in the order they are played.

See the diagrams below for examples.

== Examples for Complete Diagrams ==

=== A simple board with stones in all four corners ===

<hex>
R5 C5 Q1
Ra1 Re5
Be1 Ba5
</hex>

And the same with stones that are linked to other pages.

<hex>
R5 C5 Q1
[[Red|Ra1]] [[Red|Re5]]
[[Blue|Be1]] [[Blue|Ba5]]
</hex>

=== Numbered moves ===

<hex>
R5 C5 Q1
Mc3 Ma3 Me3 Mb2 Md4
</hex>

=== Border ===
You can draw a colored border around the diagram by giving the command <tt>B:on</tt>.

<hex>
R5 C5 Q1 B:on
Ma1 Mb2 Mc3 Md4 Me5
</hex>

=== All possible fields ===

<hex>
Q1 C11 R4
Ra1 R1b1 R2c1 R3d1 R4e1 R5f1 R6g1 R7h1 R8i1 R9j1 R0k1
Ba2 B1b2 B2c2 B3d2 B4e2 B5f2 B6g2 B7h2 B8i2 B9j2 B0k2
Sa3 *b3 Pd3 +e3
Ma4 Mb4 Mc4 Md4 Me4 Mf4 Mg4 Mh4 Mi4 Mj4 Mk4
</hex>

== Source code ==

The full source code of the plug-in is available [http://www.hexwiki.org/hex/ here].

Help:Hex

2012-11-04T13:04:25Z

Roland Illig: "game mode", especially for commenting games

This is the documentation for the MediaWiki plug-in for drawing Hex diagrams.

== Syntax ==

Hex diagrams are specified using the <tt><hex></tt>...<tt></hex></tt> tag.
Inside this tag, a series of words describes the diagram itself.
The first letter of each word is called the ''command'', and the remaining letters are its ''arguments''.
There are commands for specifying the board size and for putting stones on the board.

=== Examples ===

* <tt><hex> R5 C5 </hex></tt> draws an empty hex board with 5 rows and 5 columns.

== Setting up the board ==

Before doing anything else, you have to say how large the board is. Each board has a number of rows (which go horizontally) and columns (which go vertically). In addition to that, you can say that you want the rows and colums labelled with their letters and numbers.

The commands for setting up the board all take a single numeric argument. The commands are:

* '''R''': Specifies the number of rows of the board.
* '''C''': Specifies the number of columns of the board.
* '''Q''': Specifies whether the coordinates should be printed next to the board. Zero means ''no'', any other number means ''yes''. By default, they are not shown.

=== Examples ===

* '''R5''' sets the number of rows to 5.
* '''Q1''' makes the coordinates appear next to the board.
* '''Q0''' explicitly makes the coordinates disappear.
* '''<nowiki><hex>R5 C5 Q1</hex></nowiki>''' creates a board with five rows and five colums, which are all labelled.

<hex>R5 C5 Q1</hex>

== Setting up single stones ==

The commands for setting up stones all take a coordinate as their argument. Coordinates are written in the form ''f7'', where ''f'' is the column and ''7'' is the row.

The commands are:
* '''B''' for a blue stone.
* '''R''' for a red stone.
* '''H''' for a horizontal stone (equivalent to '''B''').
* '''V''' for a vertical stone (equivalent to '''R''').
* '''S''' or '''*''' for a star.
* '''P''' or '''+''' for a plus.

When you want to add move numbers, put a single digit (0-9) between the command and the coordinate,
for example '''R5e4''' when Red puts his fifth move onto e4.

It is also possible to link stones to any other wiki page. For that, use the form '''<nowiki>[[</nowiki>''Link_target''|''Word'']]''', where ''Word'' is used to setup the stone and ''Link_target'' is where you want to arrive when you click the link.

=== Examples ===

* '''Ba4''' puts a blue stone ('''B''') in the first column ('''a''') of the fourth row ('''4''').
* '''R7b1''' puts a red stone ('''R''') in the second column ('''b''') of the first row ('''1''') and labels it with a seven ('''7''').
* '''<nowiki>[[</nowiki>#Setting_up_single_stones|Ba5]]''' puts a blue stone on the board and links it to the section called ''Setting up single stones'' on the same page. Note that you cannot use space characters in the link.

<hex>
R5 C5 Q1
Ba4 R7b1 [[#Setting_up_single_stones|Ba5]]
</hex>

== Automatically numbered moves ==

There is a special command ('''M''') for setting up numbered sequences of moves. The first of these moves is for Red and is labelled with a ''1''. After each '''M''' command, the color changes and the move number is increased automatically.

If you want to enter a sequence of moves that starts with a blue move, write '''MB'''. This changes the color without affecting the move number or the stones on the board.

When you want to show a complete game, it can be annoying to replace the '''H'''... and '''V'''... commands with '''M'''. For this reason, there is another feature, which automatically numbers the following stones. It is switched on with '''N:on''' and off with (you guessed it) '''N:off'''.

=== Limitations ===
Currently, the number of moves is restricted to 10, but this may be extended if there is the need for it. But before you request this change, please ask yourself whether you really need it. Ten moves is a lot, and especially when analyzing games, it would be easier for the reader if you split the moves into several diagrams.

=== Examples ===
* '''MR Ma1 Ma2 Ma3 Mb4''' is a sequence of four moves, starting with a red ''1''.
* '''M5c1 Mc2 Mc3''' are three moves, starting with a red ''5''.
* '''MB Me1 Me2 Me3''' are three moves, starting with a blue ''1''.
* '''N:on Rg1 Bg7 N:off Rg4''' results in two numbered moves on g1 and g7, and one unnumbered move at g4.

<hex>
R11 C11 Q1
MR Ma1 Ma2 Ma3 Ma4
M5c1 Mc2 Mc3
M0e1
MB Me1 Me2 Me3
N:on Rg1 Bg7 N:off Rg4
</hex>

== Setting up a certain position and some moves ==

When commenting a game you usually have some moves that lead to a certain position, and from this position you want some numbered moves. This can be done using the plain coordinates.

<pre>
<hex>
R11 C11 Q1 B:on
a1 a2 a3 a4
N:on
a5 a6 a7 a8
</hex>
</pre>

* The first line sets up the board as usual.
* The second line sets up the position with alternating colors.
* The third line says that all the following moves will be numbered.
* The fourth line finally sets up the numbered moves, again with alternating colors.

<hex>
R11 C11 Q1 B:on
a1 a2 a3 a4
N:on
a5 a6 a7 a8
</hex>

The nice point is that for the next diagram you just have to remove the '''N:on''' to have the final position without numbers, so you can easily add the next moves.

== Setting up a whole line at once ==

In many cases, there are many stones on the board, and it would be annoying to write one word for each stone.
For this reason, there exists a short-cut for drawing a complete line. If a word starts with a number, followed by a colon (:) and a list of cell contents, the whole line can be drawn with only one command. The valid types of cell contents are:
* '''R''' or '''V''' for red stones,
* '''B''' or '''H''' for blue stones,
* '''*''' or '''S''' for stars,
* '''+''' or '''P''' for plus,
* '''_''' for an empty cell.

=== Limitations ===
* Stones with numbers cannot be put using this command. Instead, use the commands for putting a single stone or for putting a series of moves.

=== Examples ===
* '''3:__BBRRBBRR__*''' sets up the first 13 stones of the third row. The first two are empty, the next two are blue, and so on.

<hex>
R3 C13 Q1
3:__BBRRBBRR__*
</hex>

== Formatting diagrams usefully ==

Depending on the situation and the intent of a diagram, it may be formatted in different styles. Large diagrams should be distributed over several lines, to make editing and reading easier. The suggested format is:
# Board size and coordinates,
# Setup stones: One line per color,
# The moves in the order they are played.

See the diagrams below for examples.

== Examples for Complete Diagrams ==

=== A simple board with stones in all four corners ===

<hex>
R5 C5 Q1
Ra1 Re5
Be1 Ba5
</hex>

And the same with stones that are linked to other pages.

<hex>
R5 C5 Q1
[[Red|Ra1]] [[Red|Re5]]
[[Blue|Be1]] [[Blue|Ba5]]
</hex>

=== Numbered moves ===

<hex>
R5 C5 Q1
Mc3 Ma3 Me3 Mb2 Md4
</hex>

=== Border ===
You can draw a colored border around the diagram by giving the command <tt>B:on</tt>.

<hex>
R5 C5 Q1 B:on
Ma1 Mb2 Mc3 Md4 Me5
</hex>

=== All possible fields ===

<hex>
Q1 C11 R4
Ra1 R1b1 R2c1 R3d1 R4e1 R5f1 R6g1 R7h1 R8i1 R9j1 R0k1
Ba2 B1b2 B2c2 B3d2 B4e2 B5f2 B6g2 B7h2 B8i2 B9j2 B0k2
Sa3 *b3 Pd3 +e3
Ma4 Mb4 Mc4 Md4 Me4 Mf4 Mg4 Mh4 Mi4 Mj4 Mk4
</hex>

== Source code ==

The full source code of the plug-in is available [http://www.hexwiki.org/hex/ here].

Rules

2012-10-02T07:29:34Z

Roland Illig: Strategy comes after the rules.

== Shape of the board ==
The [[Hex]] [[board]] is composed of [[hexagon]]s, arranged in an ''n × n'' [[Wikipedia:Rhombus|rhombus]], where ''n'' is an integer greater than one. Thus Hex can be played on boards of different sizes, and which size is considered standard varies. [[Piet Hein]] used a board of size 11, while [[John Nash]] settled on size 14. Nowadays people usually use the sizes that are available on [[Online playing|game sites]] on the Internet offering Hex. [http://games.wtanaka.com/hex Games.wtanaka.com] uses sizes 11, 14 and 19; [[Little Golem]] offers the sizes 13 and 19. (See the article [[Board size]] for more.)

It is also possible to play on boards of size ''m × n'' where ''m'' and ''n'' are distinct integers, but in this case a winning strategy is known for the player with shortest distance between his sides.

This is how a typical Hex board looks:

<hex>B:on</hex>

== Playing the game ==
Hex is played by two players, who take turns placing pieces on the board. The players have different colours, say red and blue. (The players themselves are sometimes referred to as [[Red (player)|Red]] and [[Blue (player)|Blue]]) The four [[Edge|edges]] of the board are coloured with the same colours, in such a way that parallel edges have the same colour. Red wins if he can build a continuous chain between the two red edges, and blue wins if he can build such a chain between the blue edges.

== The [[swap rule]] ==
The above rules give a strong advantage to the [[first player]]. Because of this, the [[swap rule]] (also called the Pie rule) was introduced. Suppose that Red is to make the first move. Then the first player places a Red piece on the board, in any cell he likes. After that, the second player decides who will play Red and who will play Blue. Then whoever was decided to be blue makes the next move, and the game continues normally (that's how it works at [http://games.wtanaka.com/hex games.wtanaka.com] and [http://www.gamerz.net/pbmserv pbmserv]).

Another possibility to swap (without changing sides of each player) is to make a [[Piece swap|piece swap]]. That is, the second player in his first move may remove the first stone which was placed on field with coordinates (x;y) and place his/her own stone on field (y;x). That's how it works at [[Little Golem]]. These two ways of swapping are effectively the same.

== Beyond the rules ==

For more information on how best to utilize the rules, see [[Strategy]].

Main Page

2012-10-02T07:14:38Z

Roland Illig:

[[Hex]] is a [[connection game]] invented in the 1940s and popularised in recent years on game sites on the web. With simple [[rules]] and much inherent [[strategy]], it makes for a game which an increasing audience finds interesting and stimulating.

[[Image:Hexposition02.jpg|thumb|250px|A Hex game]]
Depending on your interest, some good pages to start exploring this site are:

* a description of the [[rules]] of Hex
* some [[History of Hex|historical]] background
* a strategy guide consisting of 3 levels: [[Basic (strategy guide)|basic]], [[Intermediate (strategy guide)|intermediate]], and [[Advanced (strategy guide)|advanced]]
* the [[strategy]] page has links to specific strategy topics
* Pick up an article in the list of [[Special:Allpages|all articles]], or select a [[Special:Categories|category]] you wish to get informed about
* information on [[computer Hex]]
* information on [[online playing]]
* ideas for [[physical hex sets]]
* information on [[Tournaments]]
* some [[variants using the same equipment]]
* [[Commented games]] to learn from
* Tips for [[Typesetting Hex]]
* [[Hex Bibliography]]

User talk:Oriol

2012-09-29T22:50:33Z

Roland Illig: /* Nombres a les peces */ the syntax is very similar to what Oriol wanted in the first place

i wold like to make a page with hex problems

:Sounds good. May I suggest posting them on the [[Puzzles]] page? — [[User:Turing|turing]] 11:41, 25 Jun 2006 (CEST)

But I'm new in hexwiki and I'm not shure how it works. Can I create a new page? I wold like to make a "basic" hex problems for new players.

:Yes, creating a new page is perfectly ok too if you want. Just create a link somewhere, [[This page does not exist|like this]], so that you can go to the page and add content to it. Good luck! And [[Wikipedia:Wikipedia:Be bold in updating pages|be bold]]. — [[User:Turing|turing]] 15:05, 3 Jul 2006 (CEST)

I just making some test to know how wiki works

Problem X
Vertical to play and win
<hex>R9 C9 Q1 Vg3 Vf4 Vf5 Vg5 Vh6 Vh7 Ve7 Hd9 Hd7 Hc6 Hd6 Hf7 Hg7 Hi7 Hg9</hex>

Wrong
Playing in the lader don't seems good
<hex>R9 C9 Q1 Vg3 Vf4 Vf5 Vg5 Vh6 Vh7 Ve7 Hd9 Hd7 Hc6 Hd6 Hf7 Hg7 Hi7 Hg9 Vg8 Vf8 Ve8 Hf9 He9 Hd8</hex>

Correct
<hex>R9 C9 Q1 Vg3 Vf4 Vf5 Vg5 Vh6 Vh7 Ve7 Hd9 Hd7 Hc6 Hd6 Hf7 Hg7 Hi7 Hg9 Vf8</hex>

its a test

== Puzzle X2 ==
(from templates seccion)

Blue seems connected. How can Red block it?
<hex>R7 C7 Vd5 Ve6 Hd4 He4</hex>

==Solution Puzzle X2 ==

Blue is connected to the right due to A3 template.
Blue is not connected to the left. Can connect if play in b5. Then Red must to play in one of the following *

<hex>R7 C7 Vd5 Ve6 Hd4 He4 Sa5 Sa6 Sb5 Sc4 Sc5</hex>

a6, b5 and c5 can be responded by c3 connecting with A3 template

<hex>R7 C7 Vd5 Ve6 Hd4 He4 Va6 Vb5 Vc5 Hc3</hex>

a5 can be responded by c4 connecting with B3 template

<hex>R7 C7 Vd5 Ve6 Hd4 He4 Va5 Hc4</hex>

correct solution: c4
althougt it's not sure who win

<hex>R7 C7 Vd5 Ve6 Hd4 He4 Vc4</hex>

'''Note: it's only a test, not the final hex problems page. I'm testing the edit in wiki. Can somebody help me? How I can delete or modify my talk page? I only know add comments but no modify the existing ones. Thanks'''

:To edit the page, simply click the ''edit'' button at the top of this page. Until now you have presumably clicked the +, which is next to the ''edit'' and allows you to add extra comments, but not modify the earlier ones. Note that in the diagram above, blue has an easy win if he plays b3. [[User:Taral|Taral]] 19:24, 18 Jul 2006 (CEST)

==Nombres a les peces==

Ei, pel que he vist de la manera de fer-ho, ha de ser fàcil de numerar les jugades.

La cosa seria fer:

<nowiki>
<hex ordered=yes>
R7
C7
Vd5
Hd4
Ve3
Hd6
</hex>
</nowiki>

Comenta'ls als que porten el wiki si ho podrien programar. Si et diuen que no, que no en tenen ganes o no tenen temps, digue'ls que si et passen el codi font de com es fa ara hi ha algú (jo) que ho podria fer. --[[User:Viktor|Viktor]] 22:46, 13 Aug 2006 (CEST)

:Could somebody who masters the above romance language step in and serve as an interpreter? I think I understand Viktor's question, but I'm not sure if I understand all of his additional comments... Anyway, the board rendering engine is at a dead end (because it uses a non-viable combination of PHP and HTML tables), and I would love to see a different solution where we could actually make additions like this. Kindly contact me if you would like to collaborate on such an effort. — [[User:Turing|turing]] 17:34, 15 Aug 2006 (CEST)

:Turing, this is Catalan language. I will translate it. --[[User:Gregorio|Gregorio]] 08:52, 6 Sep 2006 (CEST)

Translation:

Oriol says:

Numbers to pieces

For what I have seen, it has to be easy to number the moves.

The point is to do:

<nowiki>
<hex ordered=yes>
R7
C7
Vd5
Hd4
Ve3
Hd6
</hex>
</nowiki>

And Viktor adds:

Comment it to the admins of this wiki to see if they can program it. If they say no, they are not in mood or they don't have time, tell them to give you the current font code since there is someone (me) that can do it.

(End of Translation --[[User:Gregorio|Gregorio]] 08:58, 6 Sep 2006 (CEST))

: Do you mean something like this: <tt><nowiki><hex>R7 C7 N:on Vd5 Hd4 Ve3 Hd6</hex></nowiki></tt>? It's been documented on [[Help:Hex#Automatically_numbered_moves]] since September 2007.

: <hex>R7 C7 N:on Vd5 Hd4 Ve3 Hd6</hex>

: --[[User:Roland Illig|Roland Illig]] ([[User talk:Roland Illig|talk]]) 00:48, 30 September 2012 (CEST)

User talk:Oriol

2012-09-29T22:48:34Z

Roland Illig: /* Nombres a les peces */ answered the question

i wold like to make a page with hex problems

:Sounds good. May I suggest posting them on the [[Puzzles]] page? — [[User:Turing|turing]] 11:41, 25 Jun 2006 (CEST)

But I'm new in hexwiki and I'm not shure how it works. Can I create a new page? I wold like to make a "basic" hex problems for new players.

:Yes, creating a new page is perfectly ok too if you want. Just create a link somewhere, [[This page does not exist|like this]], so that you can go to the page and add content to it. Good luck! And [[Wikipedia:Wikipedia:Be bold in updating pages|be bold]]. — [[User:Turing|turing]] 15:05, 3 Jul 2006 (CEST)

I just making some test to know how wiki works

Problem X
Vertical to play and win
<hex>R9 C9 Q1 Vg3 Vf4 Vf5 Vg5 Vh6 Vh7 Ve7 Hd9 Hd7 Hc6 Hd6 Hf7 Hg7 Hi7 Hg9</hex>

Wrong
Playing in the lader don't seems good
<hex>R9 C9 Q1 Vg3 Vf4 Vf5 Vg5 Vh6 Vh7 Ve7 Hd9 Hd7 Hc6 Hd6 Hf7 Hg7 Hi7 Hg9 Vg8 Vf8 Ve8 Hf9 He9 Hd8</hex>

Correct
<hex>R9 C9 Q1 Vg3 Vf4 Vf5 Vg5 Vh6 Vh7 Ve7 Hd9 Hd7 Hc6 Hd6 Hf7 Hg7 Hi7 Hg9 Vf8</hex>

its a test

== Puzzle X2 ==
(from templates seccion)

Blue seems connected. How can Red block it?
<hex>R7 C7 Vd5 Ve6 Hd4 He4</hex>

==Solution Puzzle X2 ==

Blue is connected to the right due to A3 template.
Blue is not connected to the left. Can connect if play in b5. Then Red must to play in one of the following *

<hex>R7 C7 Vd5 Ve6 Hd4 He4 Sa5 Sa6 Sb5 Sc4 Sc5</hex>

a6, b5 and c5 can be responded by c3 connecting with A3 template

<hex>R7 C7 Vd5 Ve6 Hd4 He4 Va6 Vb5 Vc5 Hc3</hex>

a5 can be responded by c4 connecting with B3 template

<hex>R7 C7 Vd5 Ve6 Hd4 He4 Va5 Hc4</hex>

correct solution: c4
althougt it's not sure who win

<hex>R7 C7 Vd5 Ve6 Hd4 He4 Vc4</hex>

'''Note: it's only a test, not the final hex problems page. I'm testing the edit in wiki. Can somebody help me? How I can delete or modify my talk page? I only know add comments but no modify the existing ones. Thanks'''

:To edit the page, simply click the ''edit'' button at the top of this page. Until now you have presumably clicked the +, which is next to the ''edit'' and allows you to add extra comments, but not modify the earlier ones. Note that in the diagram above, blue has an easy win if he plays b3. [[User:Taral|Taral]] 19:24, 18 Jul 2006 (CEST)

==Nombres a les peces==

Ei, pel que he vist de la manera de fer-ho, ha de ser fàcil de numerar les jugades.

La cosa seria fer:

<nowiki>
<hex ordered=yes>
R7
C7
Vd5
Hd4
Ve3
Hd6
</hex>
</nowiki>

Comenta'ls als que porten el wiki si ho podrien programar. Si et diuen que no, que no en tenen ganes o no tenen temps, digue'ls que si et passen el codi font de com es fa ara hi ha algú (jo) que ho podria fer. --[[User:Viktor|Viktor]] 22:46, 13 Aug 2006 (CEST)

:Could somebody who masters the above romance language step in and serve as an interpreter? I think I understand Viktor's question, but I'm not sure if I understand all of his additional comments... Anyway, the board rendering engine is at a dead end (because it uses a non-viable combination of PHP and HTML tables), and I would love to see a different solution where we could actually make additions like this. Kindly contact me if you would like to collaborate on such an effort. — [[User:Turing|turing]] 17:34, 15 Aug 2006 (CEST)

:Turing, this is Catalan language. I will translate it. --[[User:Gregorio|Gregorio]] 08:52, 6 Sep 2006 (CEST)

Translation:

Oriol says:

Numbers to pieces

For what I have seen, it has to be easy to number the moves.

The point is to do:

<nowiki>
<hex ordered=yes>
R7
C7
Vd5
Hd4
Ve3
Hd6
</hex>
</nowiki>

And Viktor adds:

Comment it to the admins of this wiki to see if they can program it. If they say no, they are not in mood or they don't have time, tell them to give you the current font code since there is someone (me) that can do it.

(End of Translation --[[User:Gregorio|Gregorio]] 08:58, 6 Sep 2006 (CEST))

: Do you mean something like this: <tt><nowiki><hex>R7 C7 N:on Md5 Md4 Me3 Md6</hex></nowiki></tt>? It's been documented on [[Help:Hex#Automatically_numbered_moves]] since September 2007.

: <hex>R7 C7 N:on Md5 Md4 Me3 Md6</hex>

: --[[User:Roland Illig|Roland Illig]] ([[User talk:Roland Illig|talk]]) 00:48, 30 September 2012 (CEST)

Puzzle server

2012-09-28T07:19:46Z

Roland Illig: typo

The idea of this page is to collect the requirements to develop an online and offline hex puzzle server.
It would let the user add puzzles to a database and let others solve the puzzles.
Popular sites that have already implemented this idea for other games are http://goproblems.com/ and http://chessproblems.com/.

= Online version =
* Web server
* User interface to the puzzles (JavaScript, Java, or Flash)
* Database for recording the problems

= Offline version =
* User interface (platform independent -> Java)
* Database for recording the problems

= Volunteers? =
Do you want to help building this application? Great. Work has not yet started.

[[category:puzzle]]

Help:Hex

2012-09-27T22:37:04Z

Roland Illig: /* Source code */ The location changed.

This is the documentation for the MediaWiki plug-in for drawing Hex diagrams.

== Syntax ==

Hex diagrams are specified using the <tt><hex></tt>...<tt></hex></tt> tag.
Inside this tag, a series of words describes the diagram itself.
The first letter of each word is called the ''command'', and the remaining letters are its ''arguments''.
There are commands for specifying the board size and for putting stones on the board.

=== Examples ===

* <tt><hex> R5 C5 </hex></tt> draws an empty hex board with 5 rows and 5 columns.

== Setting up the board ==

Before doing anything else, you have to say how large the board is. Each board has a number of rows (which go horizontally) and columns (which go vertically). In addition to that, you can say that you want the rows and colums labelled with their letters and numbers.

The commands for setting up the board all take a single numeric argument. The commands are:

* '''R''': Specifies the number of rows of the board.
* '''C''': Specifies the number of columns of the board.
* '''Q''': Specifies whether the coordinates should be printed next to the board. Zero means ''no'', any other number means ''yes''. By default, they are not shown.

=== Examples ===

* '''R5''' sets the number of rows to 5.
* '''Q1''' makes the coordinates appear next to the board.
* '''Q0''' explicitly makes the coordinates disappear.
* '''<nowiki><hex>R5 C5 Q1</hex></nowiki>''' creates a board with five rows and five colums, which are all labelled.

<hex>R5 C5 Q1</hex>

== Setting up single stones ==

The commands for setting up stones all take a coordinate as their argument. Coordinates are written in the form ''f7'', where ''f'' is the column and ''7'' is the row.

The commands are:
* '''B''' for a blue stone.
* '''R''' for a red stone.
* '''H''' for a horizontal stone (equivalent to '''B''').
* '''V''' for a vertical stone (equivalent to '''R''').
* '''S''' or '''*''' for a star.
* '''P''' or '''+''' for a plus.

When you want to add move numbers, put a single digit (0-9) between the command and the coordinate,
for example '''R5e4''' when Red puts his fifth move onto e4.

It is also possible to link stones to any other wiki page. For that, use the form '''<nowiki>[[</nowiki>''Link_target''|''Word'']]''', where ''Word'' is used to setup the stone and ''Link_target'' is where you want to arrive when you click the link.

=== Examples ===

* '''Ba4''' puts a blue stone ('''B''') in the first column ('''a''') of the fourth row ('''4''').
* '''R7b1''' puts a red stone ('''R''') in the second column ('''b''') of the first row ('''1''') and labels it with a seven ('''7''').
* '''<nowiki>[[</nowiki>#Setting_up_single_stones|Ba5]]''' puts a blue stone on the board and links it to the section called ''Setting up single stones'' on the same page. Note that you cannot use space characters in the link.

<hex>
R5 C5 Q1
Ba4 R7b1 [[#Setting_up_single_stones|Ba5]]
</hex>

== Automatically numbered moves ==

There is a special command ('''M''') for setting up numbered sequences of moves. The first of these moves is for Red and is labelled with a ''1''. After each '''M''' command, the color changes and the move number is increased automatically.

If you want to enter a sequence of moves that starts with a blue move, write '''MB'''. This changes the color without affecting the move number or the stones on the board.

When you want to show a complete game, it can be annoying to replace the '''H'''... and '''V'''... commands with '''M'''. For this reason, there is another feature, which automatically numbers the following stones. It is switched on with '''N:on''' and off with (you guessed it) '''N:off'''.

=== Limitations ===
Currently, the number of moves is restricted to 10, but this may be extended if there is the need for it. But before you request this change, please ask yourself whether you really need it. Ten moves is a lot, and especially when analyzing games, it would be easier for the reader if you split the moves into several diagrams.

=== Examples ===
* '''MR Ma1 Ma2 Ma3 Mb4''' is a sequence of four moves, starting with a red ''1''.
* '''M5c1 Mc2 Mc3''' are three moves, starting with a red ''5''.
* '''MB Me1 Me2 Me3''' are three moves, starting with a blue ''1''.
* '''N:on Rg1 Bg7 N:off Rg4''' results in two numbered moves on g1 and g7, and one unnumbered move at g4.

<hex>
R11 C11 Q1
MR Ma1 Ma2 Ma3 Ma4
M5c1 Mc2 Mc3
M0e1
MB Me1 Me2 Me3
N:on Rg1 Bg7 N:off Rg4
</hex>

== Setting up a whole line at once ==

In many cases, there are many stones on the board, and it would be annoying to write one word for each stone.
For this reason, there exists a short-cut for drawing a complete line. If a word starts with a number, followed by a colon (:) and a list of cell contents, the whole line can be drawn with only one command. The valid types of cell contents are:
* '''R''' or '''V''' for red stones,
* '''B''' or '''H''' for blue stones,
* '''*''' or '''S''' for stars,
* '''+''' or '''P''' for plus,
* '''_''' for an empty cell.

=== Limitations ===
* Stones with numbers cannot be put using this command. Instead, use the commands for putting a single stone or for putting a series of moves.

=== Examples ===
* '''3:__BBRRBBRR__*''' sets up the first 13 stones of the third row. The first two are empty, the next two are blue, and so on.

<hex>
R3 C13 Q1
3:__BBRRBBRR__*
</hex>

== Formatting diagrams usefully ==

Depending on the situation and the intent of a diagram, it may be formatted in different styles. Large diagrams should be distributed over several lines, to make editing and reading easier. The suggested format is:
# Board size and coordinates,
# Setup stones: One line per color,
# The moves in the order they are played.

See the diagrams below for examples.

== Examples for Complete Diagrams ==

=== A simple board with stones in all four corners ===

<hex>
R5 C5 Q1
Ra1 Re5
Be1 Ba5
</hex>

And the same with stones that are linked to other pages.

<hex>
R5 C5 Q1
[[Red|Ra1]] [[Red|Re5]]
[[Blue|Be1]] [[Blue|Ba5]]
</hex>

=== Numbered moves ===

<hex>
R5 C5 Q1
Mc3 Ma3 Me3 Mb2 Md4
</hex>

=== Border ===
You can draw a colored border around the diagram by giving the command <tt>B:on</tt>.

<hex>
R5 C5 Q1 B:on
Ma1 Mb2 Mc3 Md4 Me5
</hex>

=== All possible fields ===

<hex>
Q1 C11 R4
Ra1 R1b1 R2c1 R3d1 R4e1 R5f1 R6g1 R7h1 R8i1 R9j1 R0k1
Ba2 B1b2 B2c2 B3d2 B4e2 B5f2 B6g2 B7h2 B8i2 B9j2 B0k2
Sa3 *b3 Pd3 +e3
Ma4 Mb4 Mc4 Md4 Me4 Mf4 Mg4 Mh4 Mi4 Mj4 Mk4
</hex>

== Source code ==

The full source code of the plug-in is available [http://www.hexwiki.org/hex/ here].

Help:Hex

2012-09-22T19:25:27Z

Roland Illig: /* Syntax */ example

This is the documentation for the MediaWiki plug-in for drawing Hex diagrams.

== Syntax ==

Hex diagrams are specified using the <tt><hex></tt>...<tt></hex></tt> tag.
Inside this tag, a series of words describes the diagram itself.
The first letter of each word is called the ''command'', and the remaining letters are its ''arguments''.
There are commands for specifying the board size and for putting stones on the board.

=== Examples ===

* <tt><hex> R5 C5 </hex></tt> draws an empty hex board with 5 rows and 5 columns.

== Setting up the board ==

Before doing anything else, you have to say how large the board is. Each board has a number of rows (which go horizontally) and columns (which go vertically). In addition to that, you can say that you want the rows and colums labelled with their letters and numbers.

The commands for setting up the board all take a single numeric argument. The commands are:

* '''R''': Specifies the number of rows of the board.
* '''C''': Specifies the number of columns of the board.
* '''Q''': Specifies whether the coordinates should be printed next to the board. Zero means ''no'', any other number means ''yes''. By default, they are not shown.

=== Examples ===

* '''R5''' sets the number of rows to 5.
* '''Q1''' makes the coordinates appear next to the board.
* '''Q0''' explicitly makes the coordinates disappear.
* '''<nowiki><hex>R5 C5 Q1</hex></nowiki>''' creates a board with five rows and five colums, which are all labelled.

<hex>R5 C5 Q1</hex>

== Setting up single stones ==

The commands for setting up stones all take a coordinate as their argument. Coordinates are written in the form ''f7'', where ''f'' is the column and ''7'' is the row.

The commands are:
* '''B''' for a blue stone.
* '''R''' for a red stone.
* '''H''' for a horizontal stone (equivalent to '''B''').
* '''V''' for a vertical stone (equivalent to '''R''').
* '''S''' or '''*''' for a star.
* '''P''' or '''+''' for a plus.

When you want to add move numbers, put a single digit (0-9) between the command and the coordinate,
for example '''R5e4''' when Red puts his fifth move onto e4.

It is also possible to link stones to any other wiki page. For that, use the form '''<nowiki>[[</nowiki>''Link_target''|''Word'']]''', where ''Word'' is used to setup the stone and ''Link_target'' is where you want to arrive when you click the link.

=== Examples ===

* '''Ba4''' puts a blue stone ('''B''') in the first column ('''a''') of the fourth row ('''4''').
* '''R7b1''' puts a red stone ('''R''') in the second column ('''b''') of the first row ('''1''') and labels it with a seven ('''7''').
* '''<nowiki>[[</nowiki>#Setting_up_single_stones|Ba5]]''' puts a blue stone on the board and links it to the section called ''Setting up single stones'' on the same page. Note that you cannot use space characters in the link.

<hex>
R5 C5 Q1
Ba4 R7b1 [[#Setting_up_single_stones|Ba5]]
</hex>

== Automatically numbered moves ==

There is a special command ('''M''') for setting up numbered sequences of moves. The first of these moves is for Red and is labelled with a ''1''. After each '''M''' command, the color changes and the move number is increased automatically.

If you want to enter a sequence of moves that starts with a blue move, write '''MB'''. This changes the color without affecting the move number or the stones on the board.

When you want to show a complete game, it can be annoying to replace the '''H'''... and '''V'''... commands with '''M'''. For this reason, there is another feature, which automatically numbers the following stones. It is switched on with '''N:on''' and off with (you guessed it) '''N:off'''.

=== Limitations ===
Currently, the number of moves is restricted to 10, but this may be extended if there is the need for it. But before you request this change, please ask yourself whether you really need it. Ten moves is a lot, and especially when analyzing games, it would be easier for the reader if you split the moves into several diagrams.

=== Examples ===
* '''MR Ma1 Ma2 Ma3 Mb4''' is a sequence of four moves, starting with a red ''1''.
* '''M5c1 Mc2 Mc3''' are three moves, starting with a red ''5''.
* '''MB Me1 Me2 Me3''' are three moves, starting with a blue ''1''.
* '''N:on Rg1 Bg7 N:off Rg4''' results in two numbered moves on g1 and g7, and one unnumbered move at g4.

<hex>
R11 C11 Q1
MR Ma1 Ma2 Ma3 Ma4
M5c1 Mc2 Mc3
M0e1
MB Me1 Me2 Me3
N:on Rg1 Bg7 N:off Rg4
</hex>

== Setting up a whole line at once ==

In many cases, there are many stones on the board, and it would be annoying to write one word for each stone.
For this reason, there exists a short-cut for drawing a complete line. If a word starts with a number, followed by a colon (:) and a list of cell contents, the whole line can be drawn with only one command. The valid types of cell contents are:
* '''R''' or '''V''' for red stones,
* '''B''' or '''H''' for blue stones,
* '''*''' or '''S''' for stars,
* '''+''' or '''P''' for plus,
* '''_''' for an empty cell.

=== Limitations ===
* Stones with numbers cannot be put using this command. Instead, use the commands for putting a single stone or for putting a series of moves.

=== Examples ===
* '''3:__BBRRBBRR__*''' sets up the first 13 stones of the third row. The first two are empty, the next two are blue, and so on.

<hex>
R3 C13 Q1
3:__BBRRBBRR__*
</hex>

== Formatting diagrams usefully ==

Depending on the situation and the intent of a diagram, it may be formatted in different styles. Large diagrams should be distributed over several lines, to make editing and reading easier. The suggested format is:
# Board size and coordinates,
# Setup stones: One line per color,
# The moves in the order they are played.

See the diagrams below for examples.

== Examples for Complete Diagrams ==

=== A simple board with stones in all four corners ===

<hex>
R5 C5 Q1
Ra1 Re5
Be1 Ba5
</hex>

And the same with stones that are linked to other pages.

<hex>
R5 C5 Q1
[[Red|Ra1]] [[Red|Re5]]
[[Blue|Be1]] [[Blue|Ba5]]
</hex>

=== Numbered moves ===

<hex>
R5 C5 Q1
Mc3 Ma3 Me3 Mb2 Md4
</hex>

=== Border ===
You can draw a colored border around the diagram by giving the command <tt>B:on</tt>.

<hex>
R5 C5 Q1 B:on
Ma1 Mb2 Mc3 Md4 Me5
</hex>

=== All possible fields ===

<hex>
Q1 C11 R4
Ra1 R1b1 R2c1 R3d1 R4e1 R5f1 R6g1 R7h1 R8i1 R9j1 R0k1
Ba2 B1b2 B2c2 B3d2 B4e2 B5f2 B6g2 B7h2 B8i2 B9j2 B0k2
Sa3 *b3 Pd3 +e3
Ma4 Mb4 Mc4 Md4 Me4 Mf4 Mg4 Mh4 Mi4 Mj4 Mk4
</hex>

== Source code ==

The full source code of the plug-in is available [http://www.hexwiki.org/mediawiki-common/extensions/hex2/ here].

James A. Cook vs. Niall, December 2010

2011-01-08T12:10:14Z

Roland Illig: changed the markup to be more wiki-like

== Game information ==
* Size: 13x13
* Red: James A. Cook
* Blue: [[user:Niall | Niall]]
* Result:
* Comments: Niall, [[user:Halladba | Halladba]]
* Location: [[Little Golem]], game [http://www.littlegolem.net/jsp/game/game.jsp?gid=1252463 1252463] in July 2010 [[monthly cup]] group 2.1

== Comments ==

<hex>
R13 C13 Q1
01:_______B_____
02:__B_____B____
03:__________B__
04:__R_R_R______
05:________R__R_
06:___BR_B__R__R
07:_______BB_B__
08:__R_B_BRB__R_
09:____BR_R_R___
10:___R_B__BR___
11:___R_R___B___
12:_B__B________
13:_____________
Ml8 Mf10 Ml5 Mi7 Mm6 Mb12 Mf11 Me11
</hex>

James Cook (http://www.littlegolem.net/jsp/game/game.jsp?gid=1252463):

=== Move 38 ===
* J2 (H4) F2 (H2) I1 (G2) G1 (B3) D3 (C3) D4 (C5) D5 (B7) D7 (C9) A13 (E11) F12
** (G11 - necessary push) G12 (H12 - Sets up K10, and threatens (H11)) H11 (I9)
** (H11) I12 (G12) G11 (G10) H10 - red is forked and blue wins
** (I11) G11 - connects to main group and blue wins

* A13
** (E11) F12
*** (G11) G12 (H12) - now I think red wins?
*** (I11) starting at J2 blue can force a connection to the RHS to get to E8 in sente, then play G11
** (I11 - red mistake) - now blue comes along the top and joins to the left through E11 later

* E11
** (C9) I12 (I9)
*** G12 (F12) G10 (H12) I11 (H10) - red wins
*** For other variants see the notes for move 36, I12 section.
** (I9) J2 (H4) F2 (H2) I1 (G2) G1 (B3) D3 (C3) D4 (C5) D5 (B7) D7 (C9) A13 - blue wins

* B12
** (C9 - blue still has D7 and A13)
*** D7 (B3) C6 (J3/F2) I12 [good for blue as now (F12) can be answered at G12]
*** A13 (F2/J3) - looks like a red win :(
** (I11) J2 (H4) F2 (H2) I1 (G2) G1 (D2) D3 (C3) D4 (C5) D5 (B7) D7 (D8) E7 (D9) A13 - blue wins
** (A13 - now (F12*) is reduced in power as E8 is directly connected) I12 (I9) G11 (F12*) G12 - blue wins

* D7
** (B3) C6 (I11) J2 (H4) F2 (H2) I1 (G2) G1 (C3) - red wins
** (B3) B2 (C3)
*** C6 [doesn't threaten the top after C3?] (I11) J2 (H4)
**** F2 (H2) I1 (G2) G1 (D2) - red wins
**** G2 (F3) F2 (D2) - red wins
** (I9 - or other move in the RHS) J2 (H4) F2 (D2) D3 (C3) D4 (C5) D5 (B7) D9 [!] (B10) B12 - blue wins?
** (C9 - can red do this? kills F12 threat?) - blue wins?

* J2 (H4) F2 [revisiting this as F10 helps with (D8) response later] (B3) B2
** (C3) E1 - blue wins
** (D2) D3 (C3) D4 (C5) D5 (B7) D7 <(D8) E7> (D9) - red wins

* C9 (D8) D9 (D2) D3 (C3) D4 (C5) D5 (B7) - red wins, he connects around at the top via (D8) to (E6) which [by forcing earlier at (H2) I1 (G2) G1] is connected to (H4) and hence the bottom.
** (I11) J2 (H4) F2

* I11
** (K11) K10 (M9) L12 (L10) J13 (J12) I13 (I12) H13 (H12) G13 (F12) G12 (G11) - red wins!
** (I9)
*** H12 (F11) E11 - red must occupy one of F12/G12/F13, but none of these work, so blue wins?
*** F12 (G12) - red wins

* I12 (I9) [red wins, because:]
** G11 (F12*) F11
*** (H11 - connected to (I9) via (H10) or (I11), connected to the bottom via (F12)) - red wins
*** (I11 - mistake) H12 - now blue wins
** H11 (H12) - red wins
** G10 (H11) - (H11) can get to the bottom with (F12/G12/H13) and to main group with (I11/H10), so red wins
** H12 (F11 - looking at D8) E11 (H11) I11 (G12) H10 (G10) - red wins
** H10 (F12*) - red wins [as below]
** F12 (G12)
** G12 (H12) I11 (G11) - red wins
** F13 (H12)
** G13 (F12*)

* C6 (F2)
* F2 (B3) D3 (C3) C6 (C5) - blue has achieved nothing

=== Move 34 ===
Why not just H4 now, because red played (L5)! Not (I7) So J4 no longer connects.
* I7 (M6)
** I12
*** (F11) E11 (H11) I11 (I9) H10 (G10) F12 (G11) H13 - blue wins!
*** (F12) H11 (I9) G10 - blue wins
*** (G11) I9 (I11) H12 (H11) G13 - blue wins
**** H11 (I11 - forced) G10 - blue wins
**** G10 (I11) - red wins!
** I11 (I9) G11 (F12*) - blue is forked (need F11 and one of: G12/H12 etc. - red wins.

* I12
** (I7) G11 (H11)
*** G13 (F12) G12 (F11) G10 (D8) B12 (D9) C13 (E11) - red wins!
*** H10 (F12) F11 (I11) - red wins
** (F11)? (H10/H11)? G12?
** (F12) H11 - blue wins? eg. (I7) G10 or (G11) I7 (M6) I9
** (G11) I7 (M6) I9 - good for blue

=== Move 32 ===
Seems like red (L8) is very powerful, blue may have to use the red top left weaknesses somehow as red seems to have bashed either (E6) or (G4) [blues choice] through to the bottom. So blue needs to attack both of those and hope that red can't defend both forever, then attack the bottom appropriately.

Argument that red has won:
If red gets (L5) then (I5) is connected to the top (J3 or H4), and to the bottom (M6 (I11 or K10) or I7 (G11 or F10). That involved the left only through (H4). So C9/B12 can't work as an attack.

* F10 (I7) H4 (J3) J4 (I4) J5 (I6) K1 (L2) K2 (L3) K5 - blue wins
* F10 (L5)
** I12
*** (F12) H11 - blue wins? eg. (I7) G10 or (G11) I7 (M6) I9
*** (G11) I7 (M6) I9 - good for blue
** G11 [G11 is basically not a good move] (F12*)
*** M6 (I7) I9 [connects to E8] (D8) B12 (D9) C13 (F11) G10 (E11) - red connects (E6) to the bottom!
*** G12 (F11) E11 (G10) M6 (I7) - red wins?
* F10 (L5 - blocking I7 and H4) I9 (M6) I11 (K11) K10 [presumably red now has a double threat at the bottom - if he can get the middle stones to the bottom then he has (I7) or (D8)] (G11) I7 [forced] (M9) and red wins [bottom -> (G11) -> (L8) -> (I5) -> (top or (G4)].
* F10 <(F11) E11> (L5 [supersedes I7, as now H4 is useless for blue]) <M6 (I7)> G11 (I9) I11 (K11) K10 (F12*) G12 (F11) G10 (E11) C9 - blue wins?

Notes on H4 related sequences:

* J5 (J4) I6 (L4) K2 (K4) F10 (I7) H4 (I3) - red connects to the top [modulo (G4) stuff anyway]!
* J5 (I6) F10 (I7 - how H4 not blocked?)

* I12
** (F10)
*** G11 (H11) H10 (F12 - now (I11) connects to the lower edge, so E12 and G11 are useless) F11 (L5)
*** C9 (L5) I7 (M6) I9 {(I11) H12 (H11)} F13 (G12) G13 (F12) E13 - red wins even if he passes now...
** (L5) F10 (G11) I6 (M6) I9 - good for blue!?
* G2 (E5)
* F2 (H2) D3 (G2 - connects to (E4)&(E6), hence connecting (E4) to the top, kinda killing the idea of spitting them)
* F4 (E5) G2 (F5) - no way to block (E4) from the top, it just joins via (C4) through (D8)
* E7 [aim is to separate reds ways to the top] (D8) E8
** (L5)
*** H4 (J3) <G11 (F10) - miai for red> - looks like an easy win for red.
F5?

At the bottom:

Red threatens: (L5), but if i play @ the top, then (D8), later on the key problem for blue is the doble threat at (F12), hence the * by it:

* I7
** (D8 - starts a forcing sequence?) B12 (D9) C13 (F10) G11 <(I9) I11> (F12*) - and red wins
** (L5)
*** I9 (M6) I11 (K11) L12 (K10) J13 (J12) I13 (I12) H13 (H12) G13 (F12) - blue win?
*** M6 (D8) B12 (D9) C13 (F10) G11 (I9) I11 (F12*) - as usual, red wins.

* L5 (D8) B12 (D9) C13
** (F10) G11 (I9) I11 (F12*) - if blue plays at G12 then (F11) connects red all the way to (E6). If blue blocks at F11 then (K11) connects around [all the way to E6] anyway!
** (F11) E11 (E10) F10 (G9) G11 (I9) I11 <(K11) K10 (M9) L12 (L10) J13 (J12) I13 (I12) H13 (H12) G13> (F12*) G12 (G10). Now red is connected: bottom, solidly around to (E6)!

* I7 (D8) B12 (D9) C13... - Question, after G11 (I9) I11 does (L8) block blue from the left? Looks like it.

* C9 (L5) - double threat (attacks I7 and H4)
** J5 (I6) K5 (K6) H4 (J3) K1 (L2) K2 (M3) I11 (I9)
*** G11 (F10) - red wins
*** G10?

=== Move 30 ===
[following notes from 28, as (J10) plays the same role as (K10)]
* K7 (I7) H4 (D8) B12 (D9) C13 (F11) E11 (E10) F10 (G9) G11 (K11) I9 - blue wins!!

=== Move 28 ===
* G8 (K10)
** K7 (I7) H4 (D8) B12 (D9) C13 (F11) E11 (E10) F10 (G9) G11 (K11) I9 - blue wins!!
** K11 (L10) K12 (J10) I11 (I7) H4 (J3) - red wins (destroyed blue ladder)

=== Move 26 ===

Red is threatening two powerful moves: (J2) [I4] and (D8) [B12].
The B12 weakness of (D8) means that red can't connect (E6) to the bottom in one move.
* G6
** (K7) K6 (L6) L5 <(J7) I9> (L11 - pointless, as the ladder never gets that far now!) K12
** (F9 - aiming at (D8) B12 (D9) C13 (F11), and also at (G7) double peep) G8
*** (F10) C9 [because (D8) is now a threat]
** (D8) B12 - good for blue?
** <(C9) D7> - good for blue?
** (H4) I7 - gfb
** (L10) K7 - gfb
** (L11) L10

* <F4 (E5)> G6 (D8) - <> exchange doesn't look like it helps
* E5 (F5) - because F2 has a weakness at (H2)
* F4 (F3) D5 (G3) H4 (G6) G5 (F6) F5 - blue wins
* H4 (G6) I7 (F8)
** F9 (G8) G10 (H10) H12 (H11) G12 (F10) - red connects (F8) to the bottom
* H4 (D8)
** B12 (D9) C13 (F10) G11 - blue wins
** E5 (F5) G2 (F3) F2 (D2) D3 (C3) D4 (C5) D5 (B7) - red wins
* D7 (H5) I7 (F8)
** G6 (F7) F5 (E5) G2 (E3) - reds connection goes: {top->E3/E4/E5 -> F7/F8 -> bottom}
** <...> F2 (?) D3 (C3) D4 (C5) D5 (B7) C9 (D8) D9 (E7) - red wins
* D7 <(E7) D8> (I7) H4 (G6) F2 (D2) D3 (C3) D4 (C5) - now red can't connect if he has played (E7)
* F2 (D2) D3 (C3) H4 (G6) G5 (E7) C6 (D5) E5 (F5) F4 (H2) I1 (G2) G1 (F3) I7 (D8) B12 - now what?
* F2 (H2) H4

=== Move 24 ===
<blah> denotes possibilty of exchanging blah
* C2
** (I7) F2 (H2) I1 (G2) G1
*** (B3) B2 (C3) <D5 (E4)> E1 (J2) I4 (I3) H4 (H3) G6
**** (C9) D7 (E7 [G6->E8 ok]) D7 (B7)
***** with <D5 (E4)> get: B6 - BLUE wins
***** without <D5 (E4)> get: D5 (B6) D4 (D2) D1 (E2) F1 (E3) E5 (F5) - RED wins!
**** (D8) D9 (B10) B12 (B11) C13 - now blue wins as G11/F10 are miai
*** (J2)
*** (D2) F4 (J2)
*** (E4) E1 (J2) I4 (I3) H4 (H3)
** (J2) C9 (I7) I4 (H5) H4 (G5) F2 (D2) E4 (D5) E5 - red has no move, blue wins
** (D2)

Close to repetition! From move 22 notes:

* I7 (C9 [B9 doesn't work with D11 because of E12]) C2
** (B3) B2 (C3) F2 (I4) I3 (D2) D5 (E5 [D4 weakness, so (E4)?]) D7 (E7) D8 (F8)
* (note the K7) K6 (L6) L5 (J7) I9 sequence)
** (D2) D7 (B7) C5, blue connects, red can play (F8), but looks like this works for blue? What if red plays (H4/G5/H5/I4), threatening an attack around (J2) before (F8)? Well, blue can play at F7 and just connect to I7 and win.
* I10 (C11 [threatens D8 connection]) C9 (I7)
** H4 (G6) G5 (E7) F2 (E4) D3 (C3), with C9 in place blue can run down the left
** C2/F2?

Question: Does I7 connect E8 to the right edge? It's a series of double threats. Attacking the direct E8--> I7 connected: If red (F8) then blue walks up to I2, however this only connects by running down to J11. So can red attack the connection of E8 to the right edge by first attacking the direct route through I7 (eg. at (K7) or (L11)) and then playing (F8) having damaged the route down the RHS?
Note* I was very worried, after playing move 22 that red would instead play at E10. This blocks E9-->I10 better than D11.

=== Move 22 ===
<pre>
/ F10 (G11) \
I10 (D11) I7 [[not needed (F8) F7 (G7) G6 (H6) G4]] (B9) C2 [see below]
\ G11 (F10) /
- (B3) B2 (C3) F2 (I4) I3 (D2) D5 (E5 [D4 weakness, so (E4)?]) D7 (E7) D8 (F8) - blue *almost* wins here. The complication is J3, leading to a ladder down the right hand side, and the possibility of a double threat earlier. Something like (K7) K6 (L6) L5 (J7) I9. So it looks like it doesn't work for red.
- (D2) D7 (B7) C5, blue connects, red can play (F8), but looks like this works for blue? What if red plays (H4/G5/H5/I4), threatening an attack around (J2) before (F8)? Well, blue can play at F7 and just connect to I7 and win.
I10 (C11 [threatens D8 connection]) C9 (I7)
- H4 (G6) G5 (E7) F2 (E4) D3 (C3), with C9 in place blue can run down the left
- C2/F2?
I10 (I7) G11 (C11)

C11 (B12) D11 (B11) C9 (E10) C10
- (G11)
- (A10), and a ladder
C11 (D9 - cuts off E8 pieces fairly thoroughly) I10 (G11)
C11 (B10) C9 (D11) - confusing...

D8s connection to both the top and the bottom?
[E3/F2 - looking at C2? C2? - ignoring F2 too much?] H4 [protect against F2, sets up G6 related moves, like C9?]
Can I get J5 in as a forcing move?
J5 (J4) - looks bad for blue
Red is in danger of playing J2 and chopping through the top. After red J2 blue can get to the E8 stones, but not to the left edge yet.
</pre>

=== Move 20 ===
* D6 (C9? B7? D7? F4?)
* E4 (D5) C2 (D2) D6 (B7) C5
* E4 (D5) C2 (B3) B2 (C3) F2 (D2) C9 (G11) F6 - looks good for blue
* E4 (D5) C2 (D2) D6 - seems to work for blue
Red can pull out (J2) at any time - that looks like a big problem!

Problem is that if I play C9, red will play a testing move like (G8). If I play G7 red can play (I7) and I10 no longer threatens anything. So red can focus on the top, with something like (K4). Then when blue plays G11 red can answer at (E10), connecting to the bottom.

=== Move 18 ===
* E5 (F5) F2[say] (I4) I3 (B6) - looks good for red, F5 seems basically connected to top and bottom
* E5 (D6) D5 (B6) C7 (D8) C6 (B10) B8 - good for blue, red has no way to the top
* D5 (F4) - red seems to connect to the top and benefit substantially from this exchange.
* E4 (D5) G5 (B10) - good for red?

=== Move 14 ===
* C5?
* E8 (F8) F5 [looking at I4 and C5, or even D6, with E8?]
* E8 (F8) F7 (G7) G6 (H6) I4 - doesn't look like quite enough for blue?
* E8 (I7) H4
* E10 (I7) I6 (J6) J5 (F8) F10 (G8) G11 (H11) - now (I7) forcing sequence connects red around to (F8)! - Bad for blue
* I7 (F8)
* D6 - doesn't connect to the left, can that be ok?
* F11 (D10) - goes badly for blue when red [later] plays E11

=== Move 12 ===
Should arguably have been at J3, as this still connects with J11. Should always stretch as much as you can (Jonatan Rydh)

=== Move 10 ===
* I8?
Suggested by 'lazyplayer' of iggamecenter:
* J6
** (G8) G7 (B10) C2 - a little harder for blue now as the 'sneaking underneath' strategy below has been killed
** (F8) G6 (E7) E8 (F7) F9 (G8) H10 (I9) I10 - very good for blue.

[[category:game record]]

James A. Cook vs. Niall, December 2010

2011-01-08T11:54:55Z

Roland Illig: /* Comments */ typo

== Game information ==
* Size: 13x13
* Red: James A. Cook
* Blue: [[user:Niall | Niall]]
* Result:
* Comments: Niall, [[user:Halladba | Halladba]]
* Location: [[Little Golem]], game [http://www.littlegolem.net/jsp/game/game.jsp?gid=1252463 1252463] in July 2010 [[monthly cup]] group 2.1

== Comments ==

<hex>
R13 C13 Q1
01:_______B_____
02:__B_____B____
03:__________B__
04:__R_R_R______
05:________R__R_
06:___BR_B__R__R
07:_______BB_B__
08:__R_B_BRB__R_
09:____BR_R_R___
10:___R_B__BR___
11:___R_R___B___
12:_B__B________
13:_____________
Ml8 Mf10 Ml5 Mi7 Mm6 Mb12 Mf11 Me11
</hex>

James Cook (http://www.littlegolem.net/jsp/game/game.jsp?gid=1252463):

Move 38:
<pre>
J2 (H4) F2 (H2) I1 (G2) G1 (B3) D3 (C3) D4 (C5) D5 (B7) D7 (C9) A13 (E11) F12
- (G11 - necessary push) G12 (H12 - Sets up K10, and threatens (H11)) H11 (I9)
- (H11) I12 (G12) G11 (G10) H10 - red is forked and blue wins
- (I11) G11 - connects to main group and blue wins

A13
- (E11) F12
- (G11) G12 (H12) - now I think red wins?
- (I11) starting at J2 blue can force a connection to the RHS to get to E8 in sente, then play G11
- (I11 - red mistake) - now blue comes along the top and joins to the left through E11 later

E11
- (C9) I12 (I9)
- G12 (F12) G10 (H12) I11 (H10) - red wins
- For other variants see the notes for move 36, I12 section.
- (I9) J2 (H4) F2 (H2) I1 (G2) G1 (B3) D3 (C3) D4 (C5) D5 (B7) D7 (C9) A13 - blue wins

B12
- (C9 - blue still has D7 and A13)
- D7 (B3) C6 (J3/F2) I12 [good for blue as now (F12) can be answered at G12]
- A13 (F2/J3) - looks like a red win :(
- (I11) J2 (H4) F2 (H2) I1 (G2) G1 (D2) D3 (C3) D4 (C5) D5 (B7) D7 (D8) E7 (D9) A13 - blue wins
- (A13 - now (F12*) is reduced in power as E8 is directly connected) I12 (I9) G11 (F12*) G12 - blue wins

D7
- (B3) C6 (I11) J2 (H4) F2 (H2) I1 (G2) G1 (C3) - red wins
- (B3) B2 (C3)
- C6 [doesn't threaten the top after C3?] (I11) J2 (H4)
- F2 (H2) I1 (G2) G1 (D2) - red wins
- G2 (F3) F2 (D2) - red wins
- (I9 - or other move in the RHS) J2 (H4) F2 (D2) D3 (C3) D4 (C5) D5 (B7) D9 [!] (B10) B12 - blue wins?
- (C9 - can red do this? kills F12 threat?) - blue wins?

J2 (H4) F2 [revisiting this as F10 helps with (D8) response later] (B3) B2
- (C3) E1 - blue wins
- (D2) D3 (C3) D4 (C5) D5 (B7) D7 <(D8) E7> (D9) - red wins

C9 (D8) D9 (D2) D3 (C3) D4 (C5) D5 (B7) - red wins, he connects around at the top via (D8) to (E6) which [by forcing earlier at (H2) I1 (G2) G1] is connected to (H4) and hence the bottom.
- (I11) J2 (H4) F2

I11
- (K11) K10 (M9) L12 (L10) J13 (J12) I13 (I12) H13 (H12) G13 (F12) G12 (G11) - red wins!
- (I9)
- H12 (F11) E11 - red must occupy one of F12/G12/F13, but none of these work, so blue wins?
- F12 (G12) - red wins

I12 (I9) [red wins, because:]
- G11 (F12*) F11
- (H11 - connected to (I9) via (H10) or (I11), connected to the bottom via (F12)) - red wins
- (I11 - mistake) H12 - now blue wins
- H11 (H12) - red wins
- G10 (H11) - (H11) can get to the bottom with (F12/G12/H13) and to main group with (I11/H10), so red wins
- H12 (F11 - looking at D8) E11 (H11) I11 (G12) H10 (G10) - red wins
- H10 (F12*) - red wins [as below]
- F12 (G12)
- G12 (H12) I11 (G11) - red wins
- F13 (H12)
- G13 (F12*)

C6 (F2)
F2 (B3) D3 (C3) C6 (C5) - blue has achieved nothing
</pre>

Move 34:
Why not just H4 now, because red played (L5)! Not (I7) So J4 no longer connects.
<pre>
I7 (M6)
- I12
- (F11) E11 (H11) I11 (I9) H10 (G10) F12 (G11) H13 - blue wins!
- (F12) H11 (I9) G10 - blue wins
- (G11) I9 (I11) H12 (H11) G13 - blue wins
- H11 (I11 - forced) G10 - blue wins
- G10 (I11) - red wins!
- I11 (I9) G11 (F12*) - blue is forked (need F11 and one of: G12/H12 etc. - red wins.

I12
- (I7) G11 (H11)
- G13 (F12) G12 (F11) G10 (D8) B12 (D9) C13 (E11) - red wins!
- H10 (F12) F11 (I11) - red wins
- (F11)? (H10/H11)? G12?
- (F12) H11 - blue wins? eg. (I7) G10 or (G11) I7 (M6) I9
- (G11) I7 (M6) I9 - good for blue
</pre>

Move 32: Seems like red (L8) is very powerful, blue may have to use the red top left weaknesses somehow as red seems to have bashed either (E6) or (G4) [blues choice] through to the bottom. So blue needs to attack both of those and hope that red can't defend both forever, then attack the bottom appropriately.

Argument that red has won:
If red gets (L5) then (I5) is connected to the top (J3 or H4), and to the bottom (M6 (I11 or K10) or I7 (G11 or F10). That involved the left only through (H4). So C9/B12 can't work as an attack.

<pre>
F10 (I7) H4 (J3) J4 (I4) J5 (I6) K1 (L2) K2 (L3) K5 - blue wins
F10 (L5)
- I12
- (F12) H11 - blue wins? eg. (I7) G10 or (G11) I7 (M6) I9
- (G11) I7 (M6) I9 - good for blue
- G11 [G11 is basically not a good move] (F12*)
- M6 (I7) I9 [connects to E8] (D8) B12 (D9) C13 (F11) G10 (E11) - red connects (E6) to the bottom!
- G12 (F11) E11 (G10) M6 (I7) - red wins?
F10 (L5 - blocking I7 and H4) I9 (M6) I11 (K11) K10 [presumably red now has a double threat at the bottom - if he can get the middle stones to the bottom then he has (I7) or (D8)] (G11) I7 [forced] (M9) and red wins [bottom -> (G11) -> (L8) -> (I5) -> (top or (G4)].
F10 <(F11) E11> (L5 [supersedes I7, as now H4 is useless for blue]) <M6 (I7)> G11 (I9) I11 (K11) K10 (F12*) G12 (F11) G10 (E11) C9 - blue wins?
</pre>

Notes on H4 related sequences:
<pre>
J5 (J4) I6 (L4) K2 (K4) F10 (I7) H4 (I3) - red connects to the top [modulo (G4) stuff anyway]!
J5 (I6) F10 (I7 - how H4 not blocked?)

I12
- (F10)
- G11 (H11) H10 (F12 - now (I11) connects to the lower edge, so E12 and G11 are useless) F11 (L5)
- C9 (L5) I7 (M6) I9 {(I11) H12 (H11)} F13 (G12) G13 (F12) E13 - red wins even if he passes now...
- (L5) F10 (G11) I6 (M6) I9 - good for blue!?
G2 (E5)
F2 (H2) D3 (G2 - connects to (E4)&(E6), hence connecting (E4) to the top, kinda killing the idea of spitting them)
F4 (E5) G2 (F5) - no way to block (E4) from the top, it just joins via (C4) through (D8)
E7 [aim is to separate reds ways to the top] (D8) E8
- (L5)
- H4 (J3) <G11 (F10) - miai for red> - looks like an easy win for red.
F5?
</pre>

At the bottom:
<pre>
Red threatens: (L5), but if i play @ the top, then (D8), later on the key problem for blue is the doble threat at (F12), hence the * by it:
I7
- (D8 - starts a forcing sequence?) B12 (D9) C13 (F10) G11 <(I9) I11> (F12*) - and red wins
- (L5)
- I9 (M6) I11 (K11) L12 (K10) J13 (J12) I13 (I12) H13 (H12) G13 (F12) - blue win?
- M6 (D8) B12 (D9) C13 (F10) G11 (I9) I11 (F12*) - as usual, red wins.

L5 (D8) B12 (D9) C13
- (F10) G11 (I9) I11 (F12*) - if blue plays at G12 then (F11) connects red all the way to (E6). If blue blocks at F11 then (K11) connects around [all the way to E6] anyway!
- (F11) E11 (E10) F10 (G9) G11 (I9) I11 <(K11) K10 (M9) L12 (L10) J13 (J12) I13 (I12) H13 (H12) G13> (F12*) G12 (G10). Now red is connected: bottom, solidly around to (E6)!

I7 (D8) B12 (D9) C13... - Question, after G11 (I9) I11 does (L8) block blue from the left? Looks like it.

C9 (L5) - double threat (attacks I7 and H4)
- J5 (I6) K5 (K6) H4 (J3) K1 (L2) K2 (M3) I11 (I9)
- G11 (F10) - red wins
- G10?
</pre>

Move 30 [following notes from 28, as (J10) plays the same role as (K10)]
<pre>
K7 (I7) H4 (D8) B12 (D9) C13 (F11) E11 (E10) F10 (G9) G11 (K11) I9 - blue wins!!
</pre>

Move 28:
<pre>
G8 (K10)
- K7 (I7) H4 (D8) B12 (D9) C13 (F11) E11 (E10) F10 (G9) G11 (K11) I9 - blue wins!!
- K11 (L10) K12 (J10) I11 (I7) H4 (J3) - red wins (destroyed blue ladder)
</pre>

Move 26:
<pre>
Red is threatening two powerful moves: (J2) [I4] and (D8) [B12].
The B12 weakness of (D8) means that red can't connect (E6) to the bottom in one move.
G6
- (K7) K6 (L6) L5 <(J7) I9> (L11 - pointless, as the ladder never gets that far now!) K12
- (F9 - aiming at (D8) B12 (D9) C13 (F11), and also at (G7) double peep) G8
- (F10) C9 [because (D8) is now a threat]
- (D8) B12 - good for blue?
- <(C9) D7> - good for blue?
- (H4) I7 - gfb
- (L10) K7 - gfb
- (L11) L10

<F4 (E5)> G6 (D8) - <> exchange doesn't look like it helps
E5 (F5) - because F2 has a weakness at (H2)
F4 (F3) D5 (G3) H4 (G6) G5 (F6) F5 - blue wins
H4 (G6) I7 (F8)
- F9 (G8) G10 (H10) H12 (H11) G12 (F10) - red connects (F8) to the bottom
H4 (D8)
- B12 (D9) C13 (F10) G11 - blue wins
- E5 (F5) G2 (F3) F2 (D2) D3 (C3) D4 (C5) D5 (B7) - red wins
D7 (H5) I7 (F8)
- G6 (F7) F5 (E5) G2 (E3) - reds connection goes: {top->E3/E4/E5 -> F7/F8 -> bottom}
- <...> F2 (?) D3 (C3) D4 (C5) D5 (B7) C9 (D8) D9 (E7) - red wins
D7 <(E7) D8> (I7) H4 (G6) F2 (D2) D3 (C3) D4 (C5) - now red can't connect if he has played (E7)
F2 (D2) D3 (C3) H4 (G6) G5 (E7) C6 (D5) E5 (F5) F4 (H2) I1 (G2) G1 (F3) I7 (D8) B12 - now what?
F2 (H2) H4
</pre>

Move 24: <blah> denotes possibilty of exchanging blah
<pre>
C2
- (I7) F2 (H2) I1 (G2) G1
- (B3) B2 (C3) <D5 (E4)> E1 (J2) I4 (I3) H4 (H3) G6
- (C9) D7 (E7 [G6->E8 ok]) D7 (B7)
- with <D5 (E4)> get: B6 - BLUE wins
- without <D5 (E4)> get: D5 (B6) D4 (D2) D1 (E2) F1 (E3) E5 (F5) - RED wins!
- (D8) D9 (B10) B12 (B11) C13 - now blue wins as G11/F10 are miai
- (J2)
- (D2) F4 (J2)
- (E4) E1 (J2) I4 (I3) H4 (H3)
- (J2) C9 (I7) I4 (H5) H4 (G5) F2 (D2) E4 (D5) E5 - red has no move, blue wins
- (D2)
</pre>

Close to repetition! From move 22 notes:
<pre>
I7 (C9 [B9 doesn't work with D11 because of E12]) C2
- (B3) B2 (C3) F2 (I4) I3 (D2) D5 (E5 [D4 weakness, so (E4)?]) D7 (E7) D8 (F8)
(note the K7) K6 (L6) L5 (J7) I9 sequence)
- (D2) D7 (B7) C5, blue connects, red can play (F8), but looks like this works for blue? What if red plays (H4/G5/H5/I4), threatening an attack around (J2) before (F8)? Well, blue can play at F7 and just connect to I7 and win.
I10 (C11 [threatens D8 connection]) C9 (I7)
- H4 (G6) G5 (E7) F2 (E4) D3 (C3), with C9 in place blue can run down the left
- C2/F2?
</pre>

Question: Does I7 connect E8 to the right edge? It's a series of double threats. Attacking the direct E8--> I7 connected: If red (F8) then blue walks up to I2, however this only connects by running down to J11. So can red attack the connection of E8 to the right edge by first attacking the direct route through I7 (eg. at (K7) or (L11)) and then playing (F8) having damaged the route down the RHS?
Note* I was very worried, after playing move 22 that red would instead play at E10. This blocks E9-->I10 better than D11.

Move 22:
<pre>
/ F10 (G11) \
I10 (D11) I7 [[not needed (F8) F7 (G7) G6 (H6) G4]] (B9) C2 [see below]
\ G11 (F10) /
- (B3) B2 (C3) F2 (I4) I3 (D2) D5 (E5 [D4 weakness, so (E4)?]) D7 (E7) D8 (F8) - blue *almost* wins here. The complication is J3, leading to a ladder down the right hand side, and the possibility of a double threat earlier. Something like (K7) K6 (L6) L5 (J7) I9. So it looks like it doesn't work for red.
- (D2) D7 (B7) C5, blue connects, red can play (F8), but looks like this works for blue? What if red plays (H4/G5/H5/I4), threatening an attack around (J2) before (F8)? Well, blue can play at F7 and just connect to I7 and win.
I10 (C11 [threatens D8 connection]) C9 (I7)
- H4 (G6) G5 (E7) F2 (E4) D3 (C3), with C9 in place blue can run down the left
- C2/F2?
I10 (I7) G11 (C11)

C11 (B12) D11 (B11) C9 (E10) C10
- (G11)
- (A10), and a ladder
C11 (D9 - cuts off E8 pieces fairly thoroughly) I10 (G11)
C11 (B10) C9 (D11) - confusing...

D8s connection to both the top and the bottom?
[E3/F2 - looking at C2? C2? - ignoring F2 too much?] H4 [protect against F2, sets up G6 related moves, like C9?]
Can I get J5 in as a forcing move?
J5 (J4) - looks bad for blue
Red is in danger of playing J2 and chopping through the top. After red J2 blue can get to the E8 stones, but not to the left edge yet.
</pre>

Move 20:
<pre>
D6 (C9? B7? D7? F4?)
E4 (D5) C2 (D2) D6 (B7) C5
E4 (D5) C2 (B3) B2 (C3) F2 (D2) C9 (G11) F6 - looks good for blue
E4 (D5) C2 (D2) D6 - seems to work for blue
Red can pull out (J2) at any time - that looks like a big problem!
</pre>

Problem is that if I play C9, red will play a testing move like (G8). If I play G7 red can play (I7) and I10 no longer threatens anything. So red can focus on the top, with something like (K4). Then when blue plays G11 red can answer at (E10), connecting to the bottom.

Move 18:
<pre>
E5 (F5) F2[say] (I4) I3 (B6) - looks good for red, F5 seems basically connected to top and bottom
E5 (D6) D5 (B6) C7 (D8) C6 (B10) B8 - good for blue, red has no way to the top
D5 (F4) - red seems to connect to the top and benefit substantially from this exchange.
E4 (D5) G5 (B10) - good for red?
</pre>

Move 14:
<pre>
C5?
E8 (F8) F5 [looking at I4 and C5, or even D6, with E8?]
E8 (F8) F7 (G7) G6 (H6) I4 - doesn't look like quite enough for blue?
E8 (I7) H4
E10 (I7) I6 (J6) J5 (F8) F10 (G8) G11 (H11) - now (I7) forcing sequence connects red around to (F8)! - Bad for blue
I7 (F8)
D6 - doesn't connect to the left, can that be ok?
F11 (D10) - goes badly for blue when red [later] plays E11
</pre>

Move 12: Should arguably have been at J3, as this still connects with J11. Should always stretch as much as you can (Jonatan Rydh)

Move 10: I8?
Suggested by 'lazyplayer' of iggamecenter:
<pre>
J6
- (G8) G7 (B10) C2 - a little harder for blue now as the 'sneaking underneath' strategy below has been killed
- (F8) G6 (E7) E8 (F7) F9 (G8) H10 (I9) I10 - very good for blue.
</pre>

[[category:game record]]

James A. Cook vs. Niall, December 2010

2011-01-08T11:51:39Z

Roland Illig: Consistent markup, diagram for move 38

== Game information ==
* Size: 13x13
* Red: James A. Cook
* Blue: [[user:Niall | Niall]]
* Result:
* Comments: Niall, [[user:Halladba | Halladba]]
* Location: [[Little Golem]], game [http://www.littlegolem.net/jsp/game/game.jsp?gid=1252463 1252463] in July 2010 [[monthly cup]] group 2.1

== Comments ==

<hex>
R13 C13 Q1
01:_______B_____
02:__B_____B____
03:__R_R_R______
04:__R_R_R______
05:________R__R_
06:___BR_B__R__R
07:_______BB_B__
08:__R_B_BRB__R_
09:____BR_R_R___
10:___R_B__BR___
11:___R_R___B___
12:_B__B________
13:_____________
Ml8 Mf10 Ml5 Mi7 Mm6 Mb12 Mf11 Me11
</hex>

James Cook (http://www.littlegolem.net/jsp/game/game.jsp?gid=1252463):

Move 38:
<pre>
J2 (H4) F2 (H2) I1 (G2) G1 (B3) D3 (C3) D4 (C5) D5 (B7) D7 (C9) A13 (E11) F12
- (G11 - necessary push) G12 (H12 - Sets up K10, and threatens (H11)) H11 (I9)
- (H11) I12 (G12) G11 (G10) H10 - red is forked and blue wins
- (I11) G11 - connects to main group and blue wins

A13
- (E11) F12
- (G11) G12 (H12) - now I think red wins?
- (I11) starting at J2 blue can force a connection to the RHS to get to E8 in sente, then play G11
- (I11 - red mistake) - now blue comes along the top and joins to the left through E11 later

E11
- (C9) I12 (I9)
- G12 (F12) G10 (H12) I11 (H10) - red wins
- For other variants see the notes for move 36, I12 section.
- (I9) J2 (H4) F2 (H2) I1 (G2) G1 (B3) D3 (C3) D4 (C5) D5 (B7) D7 (C9) A13 - blue wins

B12
- (C9 - blue still has D7 and A13)
- D7 (B3) C6 (J3/F2) I12 [good for blue as now (F12) can be answered at G12]
- A13 (F2/J3) - looks like a red win :(
- (I11) J2 (H4) F2 (H2) I1 (G2) G1 (D2) D3 (C3) D4 (C5) D5 (B7) D7 (D8) E7 (D9) A13 - blue wins
- (A13 - now (F12*) is reduced in power as E8 is directly connected) I12 (I9) G11 (F12*) G12 - blue wins

D7
- (B3) C6 (I11) J2 (H4) F2 (H2) I1 (G2) G1 (C3) - red wins
- (B3) B2 (C3)
- C6 [doesn't threaten the top after C3?] (I11) J2 (H4)
- F2 (H2) I1 (G2) G1 (D2) - red wins
- G2 (F3) F2 (D2) - red wins
- (I9 - or other move in the RHS) J2 (H4) F2 (D2) D3 (C3) D4 (C5) D5 (B7) D9 [!] (B10) B12 - blue wins?
- (C9 - can red do this? kills F12 threat?) - blue wins?

J2 (H4) F2 [revisiting this as F10 helps with (D8) response later] (B3) B2
- (C3) E1 - blue wins
- (D2) D3 (C3) D4 (C5) D5 (B7) D7 <(D8) E7> (D9) - red wins

C9 (D8) D9 (D2) D3 (C3) D4 (C5) D5 (B7) - red wins, he connects around at the top via (D8) to (E6) which [by forcing earlier at (H2) I1 (G2) G1] is connected to (H4) and hence the bottom.
- (I11) J2 (H4) F2

I11
- (K11) K10 (M9) L12 (L10) J13 (J12) I13 (I12) H13 (H12) G13 (F12) G12 (G11) - red wins!
- (I9)
- H12 (F11) E11 - red must occupy one of F12/G12/F13, but none of these work, so blue wins?
- F12 (G12) - red wins

I12 (I9) [red wins, because:]
- G11 (F12*) F11
- (H11 - connected to (I9) via (H10) or (I11), connected to the bottom via (F12)) - red wins
- (I11 - mistake) H12 - now blue wins
- H11 (H12) - red wins
- G10 (H11) - (H11) can get to the bottom with (F12/G12/H13) and to main group with (I11/H10), so red wins
- H12 (F11 - looking at D8) E11 (H11) I11 (G12) H10 (G10) - red wins
- H10 (F12*) - red wins [as below]
- F12 (G12)
- G12 (H12) I11 (G11) - red wins
- F13 (H12)
- G13 (F12*)

C6 (F2)
F2 (B3) D3 (C3) C6 (C5) - blue has achieved nothing
</pre>

Move 34:
Why not just H4 now, because red played (L5)! Not (I7) So J4 no longer connects.
<pre>
I7 (M6)
- I12
- (F11) E11 (H11) I11 (I9) H10 (G10) F12 (G11) H13 - blue wins!
- (F12) H11 (I9) G10 - blue wins
- (G11) I9 (I11) H12 (H11) G13 - blue wins
- H11 (I11 - forced) G10 - blue wins
- G10 (I11) - red wins!
- I11 (I9) G11 (F12*) - blue is forked (need F11 and one of: G12/H12 etc. - red wins.

I12
- (I7) G11 (H11)
- G13 (F12) G12 (F11) G10 (D8) B12 (D9) C13 (E11) - red wins!
- H10 (F12) F11 (I11) - red wins
- (F11)? (H10/H11)? G12?
- (F12) H11 - blue wins? eg. (I7) G10 or (G11) I7 (M6) I9
- (G11) I7 (M6) I9 - good for blue
</pre>

Move 32: Seems like red (L8) is very powerful, blue may have to use the red top left weaknesses somehow as red seems to have bashed either (E6) or (G4) [blues choice] through to the bottom. So blue needs to attack both of those and hope that red can't defend both forever, then attack the bottom appropriately.

Argument that red has won:
If red gets (L5) then (I5) is connected to the top (J3 or H4), and to the bottom (M6 (I11 or K10) or I7 (G11 or F10). That involved the left only through (H4). So C9/B12 can't work as an attack.

<pre>
F10 (I7) H4 (J3) J4 (I4) J5 (I6) K1 (L2) K2 (L3) K5 - blue wins
F10 (L5)
- I12
- (F12) H11 - blue wins? eg. (I7) G10 or (G11) I7 (M6) I9
- (G11) I7 (M6) I9 - good for blue
- G11 [G11 is basically not a good move] (F12*)
- M6 (I7) I9 [connects to E8] (D8) B12 (D9) C13 (F11) G10 (E11) - red connects (E6) to the bottom!
- G12 (F11) E11 (G10) M6 (I7) - red wins?
F10 (L5 - blocking I7 and H4) I9 (M6) I11 (K11) K10 [presumably red now has a double threat at the bottom - if he can get the middle stones to the bottom then he has (I7) or (D8)] (G11) I7 [forced] (M9) and red wins [bottom -> (G11) -> (L8) -> (I5) -> (top or (G4)].
F10 <(F11) E11> (L5 [supersedes I7, as now H4 is useless for blue]) <M6 (I7)> G11 (I9) I11 (K11) K10 (F12*) G12 (F11) G10 (E11) C9 - blue wins?
</pre>

Notes on H4 related sequences:
<pre>
J5 (J4) I6 (L4) K2 (K4) F10 (I7) H4 (I3) - red connects to the top [modulo (G4) stuff anyway]!
J5 (I6) F10 (I7 - how H4 not blocked?)

I12
- (F10)
- G11 (H11) H10 (F12 - now (I11) connects to the lower edge, so E12 and G11 are useless) F11 (L5)
- C9 (L5) I7 (M6) I9 {(I11) H12 (H11)} F13 (G12) G13 (F12) E13 - red wins even if he passes now...
- (L5) F10 (G11) I6 (M6) I9 - good for blue!?
G2 (E5)
F2 (H2) D3 (G2 - connects to (E4)&(E6), hence connecting (E4) to the top, kinda killing the idea of spitting them)
F4 (E5) G2 (F5) - no way to block (E4) from the top, it just joins via (C4) through (D8)
E7 [aim is to separate reds ways to the top] (D8) E8
- (L5)
- H4 (J3) <G11 (F10) - miai for red> - looks like an easy win for red.
F5?
</pre>

At the bottom:
<pre>
Red threatens: (L5), but if i play @ the top, then (D8), later on the key problem for blue is the doble threat at (F12), hence the * by it:
I7
- (D8 - starts a forcing sequence?) B12 (D9) C13 (F10) G11 <(I9) I11> (F12*) - and red wins
- (L5)
- I9 (M6) I11 (K11) L12 (K10) J13 (J12) I13 (I12) H13 (H12) G13 (F12) - blue win?
- M6 (D8) B12 (D9) C13 (F10) G11 (I9) I11 (F12*) - as usual, red wins.

L5 (D8) B12 (D9) C13
- (F10) G11 (I9) I11 (F12*) - if blue plays at G12 then (F11) connects red all the way to (E6). If blue blocks at F11 then (K11) connects around [all the way to E6] anyway!
- (F11) E11 (E10) F10 (G9) G11 (I9) I11 <(K11) K10 (M9) L12 (L10) J13 (J12) I13 (I12) H13 (H12) G13> (F12*) G12 (G10). Now red is connected: bottom, solidly around to (E6)!

I7 (D8) B12 (D9) C13... - Question, after G11 (I9) I11 does (L8) block blue from the left? Looks like it.

C9 (L5) - double threat (attacks I7 and H4)
- J5 (I6) K5 (K6) H4 (J3) K1 (L2) K2 (M3) I11 (I9)
- G11 (F10) - red wins
- G10?
</pre>

Move 30 [following notes from 28, as (J10) plays the same role as (K10)]
<pre>
K7 (I7) H4 (D8) B12 (D9) C13 (F11) E11 (E10) F10 (G9) G11 (K11) I9 - blue wins!!
</pre>

Move 28:
<pre>
G8 (K10)
- K7 (I7) H4 (D8) B12 (D9) C13 (F11) E11 (E10) F10 (G9) G11 (K11) I9 - blue wins!!
- K11 (L10) K12 (J10) I11 (I7) H4 (J3) - red wins (destroyed blue ladder)
</pre>

Move 26:
<pre>
Red is threatening two powerful moves: (J2) [I4] and (D8) [B12].
The B12 weakness of (D8) means that red can't connect (E6) to the bottom in one move.
G6
- (K7) K6 (L6) L5 <(J7) I9> (L11 - pointless, as the ladder never gets that far now!) K12
- (F9 - aiming at (D8) B12 (D9) C13 (F11), and also at (G7) double peep) G8
- (F10) C9 [because (D8) is now a threat]
- (D8) B12 - good for blue?
- <(C9) D7> - good for blue?
- (H4) I7 - gfb
- (L10) K7 - gfb
- (L11) L10

<F4 (E5)> G6 (D8) - <> exchange doesn't look like it helps
E5 (F5) - because F2 has a weakness at (H2)
F4 (F3) D5 (G3) H4 (G6) G5 (F6) F5 - blue wins
H4 (G6) I7 (F8)
- F9 (G8) G10 (H10) H12 (H11) G12 (F10) - red connects (F8) to the bottom
H4 (D8)
- B12 (D9) C13 (F10) G11 - blue wins
- E5 (F5) G2 (F3) F2 (D2) D3 (C3) D4 (C5) D5 (B7) - red wins
D7 (H5) I7 (F8)
- G6 (F7) F5 (E5) G2 (E3) - reds connection goes: {top->E3/E4/E5 -> F7/F8 -> bottom}
- <...> F2 (?) D3 (C3) D4 (C5) D5 (B7) C9 (D8) D9 (E7) - red wins
D7 <(E7) D8> (I7) H4 (G6) F2 (D2) D3 (C3) D4 (C5) - now red can't connect if he has played (E7)
F2 (D2) D3 (C3) H4 (G6) G5 (E7) C6 (D5) E5 (F5) F4 (H2) I1 (G2) G1 (F3) I7 (D8) B12 - now what?
F2 (H2) H4
</pre>

Move 24: <blah> denotes possibilty of exchanging blah
<pre>
C2
- (I7) F2 (H2) I1 (G2) G1
- (B3) B2 (C3) <D5 (E4)> E1 (J2) I4 (I3) H4 (H3) G6
- (C9) D7 (E7 [G6->E8 ok]) D7 (B7)
- with <D5 (E4)> get: B6 - BLUE wins
- without <D5 (E4)> get: D5 (B6) D4 (D2) D1 (E2) F1 (E3) E5 (F5) - RED wins!
- (D8) D9 (B10) B12 (B11) C13 - now blue wins as G11/F10 are miai
- (J2)
- (D2) F4 (J2)
- (E4) E1 (J2) I4 (I3) H4 (H3)
- (J2) C9 (I7) I4 (H5) H4 (G5) F2 (D2) E4 (D5) E5 - red has no move, blue wins
- (D2)
</pre>

Close to repetition! From move 22 notes:
<pre>
I7 (C9 [B9 doesn't work with D11 because of E12]) C2
- (B3) B2 (C3) F2 (I4) I3 (D2) D5 (E5 [D4 weakness, so (E4)?]) D7 (E7) D8 (F8)
(note the K7) K6 (L6) L5 (J7) I9 sequence)
- (D2) D7 (B7) C5, blue connects, red can play (F8), but looks like this works for blue? What if red plays (H4/G5/H5/I4), threatening an attack around (J2) before (F8)? Well, blue can play at F7 and just connect to I7 and win.
I10 (C11 [threatens D8 connection]) C9 (I7)
- H4 (G6) G5 (E7) F2 (E4) D3 (C3), with C9 in place blue can run down the left
- C2/F2?
</pre>

Question: Does I7 connect E8 to the right edge? It's a series of double threats. Attacking the direct E8--> I7 connected: If red (F8) then blue walks up to I2, however this only connects by running down to J11. So can red attack the connection of E8 to the right edge by first attacking the direct route through I7 (eg. at (K7) or (L11)) and then playing (F8) having damaged the route down the RHS?
Note* I was very worried, after playing move 22 that red would instead play at E10. This blocks E9-->I10 better than D11.

Move 22:
<pre>
/ F10 (G11) \
I10 (D11) I7 [[not needed (F8) F7 (G7) G6 (H6) G4]] (B9) C2 [see below]
\ G11 (F10) /
- (B3) B2 (C3) F2 (I4) I3 (D2) D5 (E5 [D4 weakness, so (E4)?]) D7 (E7) D8 (F8) - blue *almost* wins here. The complication is J3, leading to a ladder down the right hand side, and the possibility of a double threat earlier. Something like (K7) K6 (L6) L5 (J7) I9. So it looks like it doesn't work for red.
- (D2) D7 (B7) C5, blue connects, red can play (F8), but looks like this works for blue? What if red plays (H4/G5/H5/I4), threatening an attack around (J2) before (F8)? Well, blue can play at F7 and just connect to I7 and win.
I10 (C11 [threatens D8 connection]) C9 (I7)
- H4 (G6) G5 (E7) F2 (E4) D3 (C3), with C9 in place blue can run down the left
- C2/F2?
I10 (I7) G11 (C11)

C11 (B12) D11 (B11) C9 (E10) C10
- (G11)
- (A10), and a ladder
C11 (D9 - cuts off E8 pieces fairly thoroughly) I10 (G11)
C11 (B10) C9 (D11) - confusing...

D8s connection to both the top and the bottom?
[E3/F2 - looking at C2? C2? - ignoring F2 too much?] H4 [protect against F2, sets up G6 related moves, like C9?]
Can I get J5 in as a forcing move?
J5 (J4) - looks bad for blue
Red is in danger of playing J2 and chopping through the top. After red J2 blue can get to the E8 stones, but not to the left edge yet.
</pre>

Move 20:
<pre>
D6 (C9? B7? D7? F4?)
E4 (D5) C2 (D2) D6 (B7) C5
E4 (D5) C2 (B3) B2 (C3) F2 (D2) C9 (G11) F6 - looks good for blue
E4 (D5) C2 (D2) D6 - seems to work for blue
Red can pull out (J2) at any time - that looks like a big problem!
</pre>

Problem is that if I play C9, red will play a testing move like (G8). If I play G7 red can play (I7) and I10 no longer threatens anything. So red can focus on the top, with something like (K4). Then when blue plays G11 red can answer at (E10), connecting to the bottom.

Move 18:
<pre>
E5 (F5) F2[say] (I4) I3 (B6) - looks good for red, F5 seems basically connected to top and bottom
E5 (D6) D5 (B6) C7 (D8) C6 (B10) B8 - good for blue, red has no way to the top
D5 (F4) - red seems to connect to the top and benefit substantially from this exchange.
E4 (D5) G5 (B10) - good for red?
</pre>

Move 14:
<pre>
C5?
E8 (F8) F5 [looking at I4 and C5, or even D6, with E8?]
E8 (F8) F7 (G7) G6 (H6) I4 - doesn't look like quite enough for blue?
E8 (I7) H4
E10 (I7) I6 (J6) J5 (F8) F10 (G8) G11 (H11) - now (I7) forcing sequence connects red around to (F8)! - Bad for blue
I7 (F8)
D6 - doesn't connect to the left, can that be ok?
F11 (D10) - goes badly for blue when red [later] plays E11
</pre>

Move 12: Should arguably have been at J3, as this still connects with J11. Should always stretch as much as you can (Jonatan Rydh)

Move 10: I8?
Suggested by 'lazyplayer' of iggamecenter:
<pre>
J6
- (G8) G7 (B10) C2 - a little harder for blue now as the 'sneaking underneath' strategy below has been killed
- (F8) G6 (E7) E8 (F7) F9 (G8) H10 (I9) I10 - very good for blue.
</pre>

[[category:game record]]

Help:Hex

2010-09-21T21:27:20Z

Roland Illig: /* Examples */ added a complete example

This is the documentation for the MediaWiki plug-in for drawing Hex diagrams.

== Syntax ==

Hex diagrams are specified using the <tt><hex></tt>...<tt></hex></tt> tag.
Inside this tag, a series of words describes the diagram itself.
The first letter of each word is called the ''command'', and the remaining letters are its ''arguments''.
There are commands for specifying the board size and for putting stones on the board.

== Setting up the board ==

Before doing anything else, you have to say how large the board is. Each board has a number of rows (which go horizontally) and columns (which go vertically). In addition to that, you can say that you want the rows and colums labelled with their letters and numbers.

The commands for setting up the board all take a single numeric argument. The commands are:

* '''R''': Specifies the number of rows of the board.
* '''C''': Specifies the number of columns of the board.
* '''Q''': Specifies whether the coordinates should be printed next to the board. Zero means ''no'', any other number means ''yes''. By default, they are not shown.

=== Examples ===

* '''R5''' sets the number of rows to 5.
* '''Q1''' makes the coordinates appear next to the board.
* '''Q0''' explicitly makes the coordinates disappear.
* '''<nowiki><hex>R5 C5 Q1</hex></nowiki>''' creates a board with five rows and five colums, which are all labelled.

== Setting up single stones ==

The commands for setting up stones all take a coordinate as their argument. Coordinates are written in the form ''f7'', where ''f'' is the column and ''7'' is the row.

The commands are:
* '''B''' for a blue stone.
* '''R''' for a red stone.
* '''H''' for a horizontal stone (equivalent to '''B''').
* '''V''' for a vertical stone (equivalent to '''R''').
* '''S''' or '''*''' for a star.
* '''P''' or '''+''' for a plus.

When you want to add move numbers, put a single digit (0-9) between the command and the coordinate,
for example '''R5e4''' when Red puts his fifth move onto e4.

It is also possible to link stones to any other wiki page. For that, use the form '''<nowiki>[[</nowiki>''Link_target''|''Word'']]''', where ''Word'' is used to setup the stone and ''Link_target'' is where you want to arrive when you click the link.

=== Examples ===

* '''Ba4''' puts a blue stone ('''B''') in the first column ('''a''') of the fourth row ('''4''').
* '''R7b1''' puts a red stone ('''R''') in the second column ('''b''') of the first row ('''1''') and labels it with a seven ('''7''').
* '''<nowiki>[[</nowiki>#Variant_A|Ba4]]''' is like the first example, but when you click on the stone, you reach the section called ''Variant A'' on the same page.

== Automatically numbered moves ==

There is a special command ('''M''') for setting up numbered sequences of moves. The first of these moves is for Red and is labelled with a ''1''. After each '''M''' command, the color changes and the move number is increased automatically.

If you want to enter a sequence of moves that starts with a blue move, write '''MB'''. This changes the color without affecting the move number or the stones on the board.

When you want to show a complete game, it can be annoying to replace the '''H'''... and '''V'''... commands with '''M'''. For this reason, there is another feature, which automatically numbers the following stones. It is switched on with '''N:on''' and off with (you guessed it) '''N:off'''.

=== Limitations ===
Currently, the number of moves is restricted to 10, but this may be extended if there is the need for it. But before you request this change, please ask yourself whether you really need it. Ten moves is a lot, and especially when analyzing games, it would be easier for the reader if you split the moves into several diagrams.

=== Examples ===
* '''MR Ma1 Ma2 Ma3 Mb4''' is a sequence of four moves, starting with a red ''1''.
* '''M5a1 Ma2 Ma3''' are three moves, starting with a red ''5''.
* '''MB Ma1 Ma2 Ma3''' are three moves, starting with a blue ''1''.
* '''N:on Ra1 Bd7 N:off Re5''' results in two numbered moves on a1 and d7, and one unnumbered move at e5.

== Setting up a whole line at once ==

In many cases, there are many stones on the board, and it would be annoying to write one word for each stone.
For this reason, there exists a short-cut for drawing a complete line. If a word starts with a number, followed by a colon (:) and a list of cell contents, the whole line can be drawn with only one command. The valid types of cell contents are:
* '''R''' or '''V''' for red stones,
* '''B''' or '''H''' for blue stones,
* '''*''' or '''S''' for stars,
* '''+''' or '''P''' for plus,
* '''_''' for an empty cell.

=== Limitations ===
* Stones with numbers cannot be put using this command. Instead, use the commands for putting a single stone or for putting a series of moves.

=== Examples ===
* '''3:__BBRRBBRR__*''' sets up the first 13 stones of the third row. The first two are empty, the next two are blue, and so on.

== Formatting diagrams usefully ==

Depending on the situation and the intent of a diagram, it may be formatted in different styles. Large diagrams should be distributed over several lines, to make editing and reading easier. The suggested format is:
# Board size and coordinates,
# Setup stones: One line per color,
# The moves in the order they are played.

See the diagrams below for examples.

== Examples for Complete Diagrams ==

=== A simple board with stones in all four corners ===

<hex>
R5 C5 Q1
Ra1 Re5
Be1 Ba5
</hex>

And the same with stones that are linked to other pages.

<hex>
R5 C5 Q1
[[Red|Ra1]] [[Red|Re5]]
[[Blue|Be1]] [[Blue|Ba5]]
</hex>

=== Numbered moves ===

<hex>
R5 C5 Q1
Mc3 Ma3 Me3 Mb2 Md4
</hex>

=== Border ===
(This feature is work-in-progress.)
<hex>
R5 C5 Q1 B:on
Ma1 Mb2 Mc3 Md4 Me5
</hex>

=== All possible fields ===

<hex>
Q1 C11 R4
Ra1 R1b1 R2c1 R3d1 R4e1 R5f1 R6g1 R7h1 R8i1 R9j1 R0k1
Ba2 B1b2 B2c2 B3d2 B4e2 B5f2 B6g2 B7h2 B8i2 B9j2 B0k2
Sa3 *b3 Pd3 +e3
Ma4 Mb4 Mc4 Md4 Me4 Mf4 Mg4 Mh4 Mi4 Mj4 Mk4
</hex>

== Source code ==

The full source code of the plug-in is available [http://www.hexwiki.org/mediawiki-common/extensions/hex2/ here].

Help:Hex

2010-09-21T21:25:40Z

Roland Illig: /* Setting up the board */ intro

This is the documentation for the MediaWiki plug-in for drawing Hex diagrams.

== Syntax ==

Hex diagrams are specified using the <tt><hex></tt>...<tt></hex></tt> tag.
Inside this tag, a series of words describes the diagram itself.
The first letter of each word is called the ''command'', and the remaining letters are its ''arguments''.
There are commands for specifying the board size and for putting stones on the board.

== Setting up the board ==

Before doing anything else, you have to say how large the board is. Each board has a number of rows (which go horizontally) and columns (which go vertically). In addition to that, you can say that you want the rows and colums labelled with their letters and numbers.

The commands for setting up the board all take a single numeric argument. The commands are:

* '''R''': Specifies the number of rows of the board.
* '''C''': Specifies the number of columns of the board.
* '''Q''': Specifies whether the coordinates should be printed next to the board. Zero means ''no'', any other number means ''yes''. By default, they are not shown.

=== Examples ===

* '''R5''' sets the number of rows to 5.
* '''Q1''' makes the coordinates appear next to the board.
* '''Q0''' explicitly makes the coordinates disappear.

== Setting up single stones ==

The commands for setting up stones all take a coordinate as their argument. Coordinates are written in the form ''f7'', where ''f'' is the column and ''7'' is the row.

The commands are:
* '''B''' for a blue stone.
* '''R''' for a red stone.
* '''H''' for a horizontal stone (equivalent to '''B''').
* '''V''' for a vertical stone (equivalent to '''R''').
* '''S''' or '''*''' for a star.
* '''P''' or '''+''' for a plus.

When you want to add move numbers, put a single digit (0-9) between the command and the coordinate,
for example '''R5e4''' when Red puts his fifth move onto e4.

It is also possible to link stones to any other wiki page. For that, use the form '''<nowiki>[[</nowiki>''Link_target''|''Word'']]''', where ''Word'' is used to setup the stone and ''Link_target'' is where you want to arrive when you click the link.

=== Examples ===

* '''Ba4''' puts a blue stone ('''B''') in the first column ('''a''') of the fourth row ('''4''').
* '''R7b1''' puts a red stone ('''R''') in the second column ('''b''') of the first row ('''1''') and labels it with a seven ('''7''').
* '''<nowiki>[[</nowiki>#Variant_A|Ba4]]''' is like the first example, but when you click on the stone, you reach the section called ''Variant A'' on the same page.

== Automatically numbered moves ==

There is a special command ('''M''') for setting up numbered sequences of moves. The first of these moves is for Red and is labelled with a ''1''. After each '''M''' command, the color changes and the move number is increased automatically.

If you want to enter a sequence of moves that starts with a blue move, write '''MB'''. This changes the color without affecting the move number or the stones on the board.

When you want to show a complete game, it can be annoying to replace the '''H'''... and '''V'''... commands with '''M'''. For this reason, there is another feature, which automatically numbers the following stones. It is switched on with '''N:on''' and off with (you guessed it) '''N:off'''.

=== Limitations ===
Currently, the number of moves is restricted to 10, but this may be extended if there is the need for it. But before you request this change, please ask yourself whether you really need it. Ten moves is a lot, and especially when analyzing games, it would be easier for the reader if you split the moves into several diagrams.

=== Examples ===
* '''MR Ma1 Ma2 Ma3 Mb4''' is a sequence of four moves, starting with a red ''1''.
* '''M5a1 Ma2 Ma3''' are three moves, starting with a red ''5''.
* '''MB Ma1 Ma2 Ma3''' are three moves, starting with a blue ''1''.
* '''N:on Ra1 Bd7 N:off Re5''' results in two numbered moves on a1 and d7, and one unnumbered move at e5.

== Setting up a whole line at once ==

In many cases, there are many stones on the board, and it would be annoying to write one word for each stone.
For this reason, there exists a short-cut for drawing a complete line. If a word starts with a number, followed by a colon (:) and a list of cell contents, the whole line can be drawn with only one command. The valid types of cell contents are:
* '''R''' or '''V''' for red stones,
* '''B''' or '''H''' for blue stones,
* '''*''' or '''S''' for stars,
* '''+''' or '''P''' for plus,
* '''_''' for an empty cell.

=== Limitations ===
* Stones with numbers cannot be put using this command. Instead, use the commands for putting a single stone or for putting a series of moves.

=== Examples ===
* '''3:__BBRRBBRR__*''' sets up the first 13 stones of the third row. The first two are empty, the next two are blue, and so on.

== Formatting diagrams usefully ==

Depending on the situation and the intent of a diagram, it may be formatted in different styles. Large diagrams should be distributed over several lines, to make editing and reading easier. The suggested format is:
# Board size and coordinates,
# Setup stones: One line per color,
# The moves in the order they are played.

See the diagrams below for examples.

== Examples for Complete Diagrams ==

=== A simple board with stones in all four corners ===

<hex>
R5 C5 Q1
Ra1 Re5
Be1 Ba5
</hex>

And the same with stones that are linked to other pages.

<hex>
R5 C5 Q1
[[Red|Ra1]] [[Red|Re5]]
[[Blue|Be1]] [[Blue|Ba5]]
</hex>

=== Numbered moves ===

<hex>
R5 C5 Q1
Mc3 Ma3 Me3 Mb2 Md4
</hex>

=== Border ===
(This feature is work-in-progress.)
<hex>
R5 C5 Q1 B:on
Ma1 Mb2 Mc3 Md4 Me5
</hex>

=== All possible fields ===

<hex>
Q1 C11 R4
Ra1 R1b1 R2c1 R3d1 R4e1 R5f1 R6g1 R7h1 R8i1 R9j1 R0k1
Ba2 B1b2 B2c2 B3d2 B4e2 B5f2 B6g2 B7h2 B8i2 B9j2 B0k2
Sa3 *b3 Pd3 +e3
Ma4 Mb4 Mc4 Md4 Me4 Mf4 Mg4 Mh4 Mi4 Mj4 Mk4
</hex>

== Source code ==

The full source code of the plug-in is available [http://www.hexwiki.org/mediawiki-common/extensions/hex2/ here].

User:Pttuanzhang

2010-07-04T20:30:50Z

Roland Illig: spam

Intermediate (strategy guide)

2010-06-12T22:36:58Z

Roland Illig: /* Minimal edge templates */ B -> *

''Adapted with permission from Glenn C. Rhoads strategy guide.''

== Loose connections ==
''(See also the article [[Loose connection]])''

[[Adjacent move]]s provide a guaranteed connection but cover little ground. [[Bridge|Two-bridges]] cover twice the distance and are almost as strong. The next best connection when even more distance is required is called the '''loose connection''' — a [[Hex (board element)|hex]] that is a two-bridge plus an adjacent step away.

<hex>R4 C5 Vb2 Sc2 Sc3 Vd3</hex>

The [[piece]]s of the loose connection [[threat]]en to connect via a two-bridge plus an adjacent step [[Multiple threats|in two different ways]] — by playing at either of the marked hexes. Also, the two marked hexes are the only ones that are in the [[overlapping connections|overlap]] of the two [[Template|connection patterns]]. Thus, to break a loose connection, one must play in one of the marked hexes.

Another connection pattern that is useful to be aware of is two pieces in the same row or column that are three hexes apart.

<hex>R5 C6 Sd2 Vb3 Pc3 Pd3 Ve3 Sc4</hex>

The pieces threaten to connect via 2 two-bridge steps in two different ways, namely by playing at piece at one of the hexes marked with a *. There are two hexes that are in the overlap between these two connection threats and a move played in either of them breaks the immediate connection (these two hexes are marked with a +). This connection pattern is not as strong as the loose connection.

== The useless triangle ==
''(See also the article [[Useless triangle]])''

When a piece's neighboring hexes are [[occupied hex|filled]] by the [[opponent]] such that that piece has only two empty neighboring hexes that are also [[adjacent]] to each other, then the piece is said to lie in a "'''useless triangle'''."

<hex>R7 C7 Q1 Vc5 Hd4 Hc4 Hb5 Hd5 Vd7 He7 Vf7</hex>

In the above diagram, the red piece at c5 and the [[empty hex]]es b6 and c6 form a useless triangle. The blue piece at e7 and the empty hexes e6 and f6 also form a useless triangle. The important point is that unless the piece in a useless triangle is in that player's [[First row|border row]], the piece has effectively been removed from the game — that is, it cannot have any effect on the rest of the game regardless of the rest of the position.

== Minimal edge templates ==

An '''edge template''' is a pattern of empty hexes that will allow a piece to be [[Connection|connected]] to the [[edge]] even if the opponent has the next move. Just as the two-bridge is a useful connection pattern to know, so are minimal edge templates — the ones of the smallest size. (The templates are numbered according to row of the [[connecting piece]]).

In the templates, all points that are irrelevant for the connection are marked with a star. Important points are marked with a plus, and everything else is left empty.

=== [[Template I]] ===

Trivially, a piece on an edge row (labelled "1" in the diagram) is connected to the edge.

<hex>R2 C3 Q1 1:*R* 2:*R* R1b2</hex>

=== [[Template II]] ===

<hex>R3 C4 Q1 1:**R* 2:**R* 3:*__*</hex>

If the opponent plays inside the template, [[Red (player)|Red]] plays the other move in the template restoring the connection to the edge.

For templates farther away, the general strategy to apply when the opponent intrudes on the template is to make a move in the template that reduces to a smaller and closer template.

=== [[Template IIIa]] ===
''(Also called [[Ziggurat]])''

<hex>
R4 C6 Q1
1:***R**
2:***R_*
3:**+_+*
4:*____*
</hex>

If the opponent intrudes on the template, then Red plays at one of the two marked points achieving [[template II]]. Since the c3 template and the two-chain/e3 template combination don't overlap, the opponent cannot stop both. (This template exists in a mirror image form with the red piece at e2).

=== Template IIIb ===
[[Image:Template-1-3b.png]]



The clear hex in the above diagram is not part of the minimal template and can be occupied by a blue piece without disturbing the red piece's connection to the bottom edge. An intrusion can be met by two chaining either left/down or right/down to edge template II. The two two-chain/edge template II combinations do not overlap, hence blue cannot stop both threats.

=== Template IVa ===
[[Image:Template-1-4a.png]]


In all cases, an intrusion can be met by reducing to a smaller edge template either by stepping one hex or by two-chaining.

=== Template IVb ===
[[Image:Template-1-4b.png]]


Again, the clear hex is not part of the template and may be occupied by a blue piece without disturbing the connection to the bottom. An intrusion can be met by two chaining either left/down or right/down to edge template IIIa. The two two-chain/edge template IIIa combinations do not overlap, hence blue cannot stop both.

=== See also ===

Continue with the page [[Edge templates everybody should know]].

== Forming ladders ==
''(See also the article [[Ladder]])''

A '''ladder''' occurs when one player tries to force a connection to an edge but is kept a constant distance away by the opponent, resulting in a sequence of moves parallel to the edge. The following is an example with Red to play.

<hex>R9 C9 Q1 Ve3 Vd4 Vd5 Vc6 Vc7 Hb8 Hb9 Hd7 He6 Hf6</hex>

Suppose Red plays c8 which forces c9 in reply. Now Red can play the following forcing sequence. d8, d9, e8, e9, f8, f9, etc. A sequence of such plays parallel to an edge is called a ladder.

<hex>R9 C9 Q1 Ve3 Vd4 Vd5 Vc6 Vc7 Hb8 Hb9 Hd7 He6 Hf6
Mc8 Mc9 Md8 Md9 Me8 Me9 Mf8 Mf9</hex>

Note that the [[Blue (player)|Blue]]'s responses are forced. If Red blindly continues the ladder all the way to end, then he will simply lose (Blue will get pieces in row 9 from b9 through i9). There is no good reason to ever force a ladder all the way through to end, it only helps your opponent.

=== Ladder escapes ===
''(See also the article [[Ladder escape]])''

Consider the same position as before but suppose Red has an additional piece at h8.

<hex>R9 C9 Q1 Ve3 Vd4 Vd5 Vc6 Vc7 Hb8 Hb9 Hd7 He6 Hf6 Vh8</hex>

This additional piece forms a '''ladder escape''' which allows Red to jump a move ahead of the ladder and win the game. The piece at h2 is called the "[[escape piece]]." Red should now play along the ladder as before, forcing Blue's response at each step. After c8, c9, d8, d9, e8, e9, f8, f9, g8 Red is connected to the bottom.

<hex>R9 C9 Q1 Ve3 Vd4 Vd5 Vc6 Vc7 Hb8 Hb9 Hd7 He6 Hf6 Vh8 Mc8 Mc9 Md8 Md9 Me8 Me9 Mf8 Mf9 Mg8</hex>

In general, for a ladder escape to be successful, it should be safely connected to the edge and not interfere with the ladder's [[Projected ladder path|projected path]].

=== Ladder escape templates ===
''(See also the article [[Ladder escape template]])

* [[Second row|Row-2]] ladders: All of the [[edge template]]s described earlier are valid.
* [[Third row|Row-3]] ladders: Templates [[Template II|II]], [[Template IIIa|IIIa]] when the escape piece is on the near side towards the ladder, and [[Template IVa|IVa]] are valid.
* [[Fourth row|Row-4]] ladders: [[Template IIIa]], near side is valid. Also [[template IVa]] is valid if you can double two-bridge to the [[escape piece]] as follows.

<hex>R6 C9 Vb3 Vc3 Vd3 Sf2 Vg3 Ha4 Hb4 Hc4 Hd4</hex>

Red can jump ahead to the escape template by playing at the marked hex.

=== The ladder escape fork ===
''(See also the article [[Ladder escape fork]])''

If you are forced onto a ladder and no convenient escape is present, then you must create one. The best way is to play one of the valid ladder escape templates that threatens another strong connection. Such a move is called a '''ladder escape fork'''. For an example, see the first example in the upcoming section "forcing moves." The first forcing move is a ladder escape fork played just prior to the formation of the ladder (and a very short ladder at that). A ladder escape fork is frequently a [[killer move]].

=== Foiling ladder escapes ===
''(See also the article [[Foiling ladder escapes]])''

In order to successfully stop a ladder escape, you must either block the [[projected ladder path]] from connecting to the escape piece or intrude on the ladder escape template. To successfully stop a ladder escape fork, you need to do both with a single move and almost always with a move that is [[Adjacent move|adjacent]] to the escape piece. The following is an example of foiling a ladder escape fork.

<hex>R9 C9 Q1 Vg3 Vf4 Vf5 Vg5 Vh6 Vh7 Hc6 Hd6 He7 Hf7 Hg7 Hi7 Hg9 +c7 +b8 +c8 +d8 +a9 +b9 +c9 +d9 Md7</hex>

Red has just played a forking ladder escape at d7. This piece is connected to the edge via template IIIa as shown by the marked hexes. Red is threatening to create an unbeatable chain by playing at E6 and the edge template is a valid ladder escape for the row-2 ladder starting G8, F9, F8, etc. To stop this, Blue needs to play a move that blocks the ladder path from connecting to the escape piece and that also intrudes on the escape template. Blue can achieve both aims by playing at D8 (which is adjacent to the escape piece). Red responds by playing C8 re-establishing the connection to the edge (there is nothing better). Now Blue continues by playing E6 blocking the forking path obtaining a [[win|winning position]].

<hex>R9 C9 Q1 Vg3 Vf4 Vf5 Vg5 Vh6 Vh7 Hc6 Hd6 Hd8 He6 He7 Hf7 Hg7 Hi7 Hg9 Md7 Md8 Mc8 Me6</hex>

Consider the same initial position but with Blue's piece on e7 removed.

<hex>R9 C9 Q1 Vg3 Vf4 Vf5 Vg5 Vh6 Vh7 Hc6 Hd6 Hf7 Hg7 Hi7 Hg9 +c7 +b8 +c8 +d8 +a9 +b9 +c9 +d9 Md7</hex>

This change may look inconsequential but now Blue cannot foil the forking ladder escape. Suppose the play goes d8, c8, e6 as before.

<hex>R9 C9 Q1 Vg3 Vf4 Vf5 Vg5 Vh6 Vh7 Hc6 Hd6 Hf7 Hg7 Hi7 Hg9 Md7 Md8 Mc8 Me6</hex>

Now Red can ladder up to E8 by the sequence G8, F9, F8, E9, E8 achieving the following position.

<hex>R9 C9 Q1 Vg3 Vf4 Vf5 Vg5 Vh6 Vh7 Hc6 Hd6 Hf7 Hg7 Hi7 Hg9 Md7 Md8 Mc8 Me6 Mg8 Mf9 Mf8 Me9 Me8</hex>

Now if Blue stops the e8 piece from connecting to the [[Bottom edge|bottom]] by playing d9, Red responds by playing e7 connecting to the bottom anyway. This example illustrates that a potential foiling move that leaves vulnerable points is unlikely to succeed against a forking ladder escape. The proper handling of ladders and ladder escapes is a complex matter and it is where many games are won or lost.

=== Pre-ladder formations ===

It's important to recognize situations in which a ladder is about to form or which could be formed. Such recognition allows you to play pieces that also serve as ladder escapes before the ladder occurs. It also allows you to play defensive moves that also block potential ladder paths prior to the existence of the ladder. By far the most common pre-ladder formation is the following "[[Bottleneck]] formation."

<hex>R5 C7 Q1 Hd3 Ve3 Hf3 Hd5</hex>

Red can now form a ladder by playing e4, e5, f4, f5, etc. or by playing d4, c5, c4, b5, etc. Such formations typically occur due to blocking a player from directly connecting to an edge as in the following example.

<hex>R5 C7 Q1 Vg1 Ve2 Hf3</hex>

In order to block Red from connecting to the bottom edge, Blue plays d3 creating a [[bottleneck]]. Red responds with e3 squeezing through and then Blue blocks with d5 completing the formation in the previous diagram.

The other common pre-ladder formation occurs when the defender is blocking the connection to an edge via a classic block as in the following diagram.

<hex>R5 C7 Q1 Ve1 Hd4</hex>

Red can form a ladder by playing d3, c4 and then laddering either to the left or right (c3, b4, b3, a4 or e3, e4, f3, f4, etc.)

== Forcing moves ==
''(See also the article [[Forcing move]])''

'''Forcing moves''' are moves that make a threat that your opponent must reply to on their next turn. Common forcing moves include playing in one of the [[Empty hex|open hexes]] in a two-chain (threatening to break the link), intrusion into an edge template, or threatening an immediate strong connection or win. Consider the following position with the [[red|vertical player]] to move.

<hex>R9 C9 Q1 Vg3 Vg4 Vf5 Vh5 Hc7 Hd8 Hf7 Hh7</hex>

At first glance, the position looks bad for Red, but Red can win by making a couple of forcing moves. He plays at e8 threatening to play at e7 on his next turn which would create an unbeatable winning chain. Blue has little choice but to stop this threat by playing e7 (there is nothing better). The move e8 is a forcing move.

The forcing nature of the move allows Red to place a piece on the other side of Blue's line without giving Blue any time to do anything constructive. The e8 piece on the other side is connected to the bottom and is of critical importance.

Red continues by playing another forcing move at g7. The only move that stops this piece from immediately connecting to the bottom edge is f9. But after f9, Red completes the win by playing at f8.

<hex>R9 C9 Q1 Vg3 Vg4 Vf5 Vh5 Hc7 Hd8 Hf7 Hh7 Me8 Me7 Mg7 Mf9 Mf8</hex>

The group of red pieces near the bottom are connected to the bottom edge. These pieces are connected via two-chains to the [[group]] g3-g4-f5 which is in turn connected to the top edge via edge [[template IIIa]].

(Note: the two forcing moves could just as easily be played in the reverse order. That is Red plays g7, Blue is forced to respond with f9, and then Red plays e8 which threatens to form an unbeatable chain in two distinct ways.)

In general terms, you have three options when responding to a forcing move in a [[Bridge|two-chain]].

# [[Saving a connection|Save]] the link by playing the other move in the two-chain.
# [[Ignoring a threat|Play elsewhere]] (e.g. playing another move may give another way of meeting the threat thus rendering it harmless)
# [[Counterthreat|Respond]] with a forcing move of your own.

=== Breaking edge templates via forcing moves ===

Forcing moves are also the only way to successfully defeat an edge template. This is done by making a [[template intrusion]] that is also a more threatening forcing move. After the opponent responds to the greater threat, you can play another move within the template and destroy the connection to the edge. For example, consider the following position with the vertical player to move.

<hex>R9 C9 Q1 Hc3 Hd3 He3 Hf2 Hg1 Hg3 Vd7 Ve6 Ve5 Ve4 Vf3 Vh5 Si1 Si2 Si3 Si4 Sh2 Sh3 Sh4 Sg4</hex>

The piece on g3 is connected to the right edge via [[template IIIa]] indicated by the '*'s. Red's best move is to play at h2. This intrudes on the edge template, is connected to the top via edge [[template II]], and threatens to complete an unbeatable chain by playing at g2 next turn. Blue can stop this threat only by playing at g2. Then Red Plays i3 breaking Blue's connection to the right.

<hex>R9 C9 Q1 Hc3 Hd3 He3 Hf2 Hg1 Hg3 Vd7 Ve6 Ve5 Ve4 Vf3 Vh5 Mh2 Mg2 Mi3</hex>

=== Using forcing moves to steal territory ===
''(See also the article [[Stealing territory]])''

I'll define '''territory''' to be the number of empty hexes adjacent to your pieces. By playing a forcing move in one of the empty hexes in a two-chain, a player can steal territory at no cost.

<hex>R5 C5 Hc2 Hb4 Vd2 Vd3 Sb3</hex>

In this position, Blue has two more hexes of territory than Red (9 vs. 7 [[adjacent hex]]es). Suppose Red makes the forcing move at the indicated hex and Blue saves the link.

<hex>R5 C5 Hc2 Hb4 Vd2 Vd3 Mb3 Mc3</hex>

Now Red has two more hexes of territory; i.e. Red has stolen 4 hexes of territory without disturbing either player's connections. Significantly, the additional territory is on the other side of Blue's connection where it may potentially be used for a future threat. The additional territory can't hurt and sometimes it makes a crucial difference.

A forcing move is [[Irrelevant move|harmless]] if it gains no territory for the opponent. You should not be worried at all about leaving harmless forcing moves available for your opponent. When you have more than one way of completing a connection with a two-bridge, e.g. when completing the [[loose connection]] described previously, you should consider which forcing move is least valuable for your opponent. Consider the following position with Red to play.

<hex>R5 C6 Q1 Vd2 He3 Hb4 Vd4 Hb5</hex>

Red wants to connect the d4 piece to the d2 piece. There are three distinct moves that accomplish this, d3, c4 (two-chaining to d2), and c3 (two-chaining to d4).

There is not much to be said about d3; it [[Direct connection|directly connects]] without altering anything else. c4 connects but gives a potentially useful forcing move to Blue. Blue can respond with c3 and suppose Red saves the connection with d3. Now Blue has gained a free hex of territory, the hex c2 is now directly adjacent to the c3/b4/b5 group when it wasn't previously. Hence, c4 is worse than d3.

Now consider the last remaining possibility c3. This leaves two forcing moves for Blue but both of them are completely harmless! If after c3, Blue plays one of the forcing moves c4 or d3, then Red can save the link and Blue will not have gained any territory at all — any empty hexes adjacent to the forcing piece were already adjacent to Blue's existing pieces. Hence, c3 is just as safe as d3 but significantly, c3 ''gains'' one hex! — b3 is now adjacent to Red's d2/b3 group when it wasn't before. Thus, c3 is better than d3 and is the best of three choices.

== Using edge templates to block your opponent ==

If your opponent has not completed an [[edge template]] but is threatening to do so in multiple ways, then the only defensive moves that stop the immediate threatened connections are those in the overlap between all threatened template connections. Suppose you are trying to stop the vertical player from connecting to the [[bottom edge]] in the following example.

<hex>R5 C6 Q1 Ve2 Hf3</hex>

The vertical player has not formed an edge template but is threatening to do so in the following four different ways.

{|
| <hex>R5 C6 Q1 Ve2 Hf3 Sd3 Se3 Sd4 Sc5 Sd5</hex> || <hex>R5 C6 Q1 Ve2 Hf3 Sd3 Se3 Sc4 Sd4 Se4 Sb5 Sc5 Sd5 Se5</hex>
|-
| <center>''Two-chain to [[template II]] at d4''</center> || <center>''Adjacent move to [[template IIIa]] at d3 and e3''</center>
|-
| <hex>R5 C6 Q1 Ve2 Hf3 Sc3 Sd3 Sb4 Sc4 Sd4 Sa5 Sb5 Sc5 Sd5</hex> || <hex>R5 C6 Q1 Ve2 Hf3 Sc3 Sd3 Se3 Sb4 Sc4 Sd4 Se4 Sa5 Sb5 Sd5 Se5</hex>
|-
| <center>''Adjacent move to template IIIa at d3'' || <center>''Adjacent move to [[template IIIb]] at d3''</center>
|}

The only three [[Hex (board element)|hexes]] in the overlap among all these edge templates are marked on the following diagram. To stop the immediate connection, the horizontal player must play at one of them.

<hex>R5 C6 Q1 Ve2 Hf3 Sd3 Sd4 Sd5</hex>

== On connectivity ==

=== Overlapping connections ===
''(See also the article [[Overlapping connections]])''

One should be alert to the situations where various connections, edge templates, and potential connections overlap at some hex(es). Consider the following position with Blue to move.

<hex>R11 C11 Q1 Vj2 Vi4 Vj5 Vi7 Vi9 Vh9 Vg9 Vf9 Se9 Ve8 Vd10 Hg7 Hf7 He6 Hc7 Hc9 He10 Hf10 Hg10 Hh10 Hi10</hex>

At first glance, it appears that Red has an unbreakable winning path. j2 cannot be stopped from connecting to the [[Top edge|top]], j2 is connected the [[group]] f9-g9-h9-i9 through a series of unbreakable two-chains, this group is connected to e8 via a two-chain, e8 is connected to d10 via another two-chain, and d10 cannot be stopped from connecting to the [[Bottom edge|bottom]].

Appearances are deceiving; it is Blue that has a forced win! The [[Weakest link|flaw]] in Red's formation is that the two-chain from f9 to e8 and the two-chain from e8 to d10 [[overlapping connections|overlap]] at the hex marked by a '*' in the diagram (e9). Blue should play at e9. By playing in the overlap, Blue is threatening to break ''both'' two-chains containing this hex. Red cannot save them both.

If Red responds with f8, then Blue plays d9 breaking the two-chain and establishing an unbeatable chain. If Red saves the other link by responding with d9, then Blue breaks through with f8 again establishing an unbeatable chain.

(However, Red could possibly respond with a9, so a bit more thought is required.)

=== Disjoint steps ===

When a piece can be connected to a group of pieces in one move in two non-overlapping ways, then they can be thought of as already connected to the group. Consider the following position.

<hex>R5 C5 Q1 Vc2 Vd2 Vb3 Hc3 Ha5 Hd4</hex>

Red's three pieces are connected to the top. How can Red extend this connection downward? By playing at c4! The piece at c4 is connected to the group of three vertical pieces in two non-overlapping ways; namely, through the hexes b4 and d3. The diagrammed connection pattern is a fairly common occurrence and the connection to the piece at c4 is just as strongly connected as the pieces in a two-chain.

=== Groups ===
''(See also the article [[Group]])''

A '''group''' is a collection of pieces that, considered in isolation from the rest of the position, have an unbreakable connection with each other. As you improve, it is important to learn to think in terms of safely connected groups of pieces. To illustrate why, consider the following two hex puzzles taken from [[Cameron Browne]]'s book "[[Hex Strategy Making the Right Connections|Hex Strategy]]."

<hex>R11 C11 Q1 Hj2 Hh3 Hc4 Vd4 Hf4 Vi4 Vj4 Vd5 Vg5 Hh5 Vi5 Vk5 Ve6 Hf6 Hg6 Hh6 Hi6 He7 Vg7 Hi7 Vj7 Vc8 Vi9</hex>

It is Blue's turn; how can he win?. The chain of pieces j2-h3-f4 is connected to the right edge and furthermore, Blue has no other way of connecting to the right edge. So to win, Blue has to extend this chain to the left edge. Looked at in isolation, there doesn't seem to be any way to do this, yet by thinking in terms of connected groups, the solution falls out easily.

Notice that the j2-h3-f4 chain threatens to connect to the i7-i6-h6-h5-g6-f6-e7 group in two non-overlapping ways, through locations h4 and f5. Hence, these two groups can be thought of as a single group of pieces already connected to the right edge (this is another example of "'''disjoint steps'''"). Now notice the key hex d6. This hex threatens to connect to Blue's big group in two distinct non-overlapping ways (through e5 and d7) hence a piece played at d6 would be part of the big group (disjoint steps again!). Furthermore, a blue piece at d6 could not be stopped from connecting to the left because the c4 piece acts as a ladder escape. Therefore, d6 wins.

<hex>R11 C11 Q1 Hj2 Vc3 Hd3 Vg3 Hj3 Hc4 He4 Vc5 Vd5 Hg5 Vi5 Vd6 He6 Vd7 Ve7 Vh7 Hb9</hex>

Again, it is Blue's turn and the task is to [[win]]. The c4 piece cannot be stopped from connecting to the left edge since after the block a5, Red can ladder down row B to the escape piece at b9. Hence, the group c4-d3-e4 is connected to the [[left edge]]. The group j2-j3 is connected to the [[right edge]]. Blue has a third group e6-g5. If Blue can play a single move that connects the e6-g5 group to both other groups, then this would be a winning move. Blue has a unique move which does this, namely play at g4. The g4-g5-e6 group is connected to the left group through f4 and e5. It threatens to connect to the j2-j3 group via h3 and i4. h3 is directly connected to g4 and two-chains to j2. None of the hexes involved, h3, i2, and i3, is involved in the connection threat i4 plus the two chain to g5. I.e. the threats don't overlap and hence the connection cannot be stopped. Therefore, g4 wins.

There is another way of coming up with this move. Red threatens to cut off the e6-g5 group to the left by two-chaining from g3 to f5. Red is also threatening to cut off the e6-g5 from the right by two-chaining from g3 to h4. However, these threats overlap and hence, Blue can stop them both by playing in the unique hex contained in the overlap, namely g4 again.

This illustrates that [[offense equals defense|offence equals defence]] in hex. Playing in regions of overlapping threats in order to stop all the threats is a defensive way of thinking. Trying to establish unbreakable connections between groups of your pieces is an offensive way of thinking. In this example, both offensive and defensive thinking techniques lead you to the unique best move. A lot of times defensive thinking is easier but sometimes offensive thinking is.

== Conclusion ==

The first two strategy guides cover what I consider to be the fundamentals of [[strategy|hex strategy]]. This information should be enough to move up into the 1800s or 1900s on [[PlaySite]]. To move up the ranks of the red guys (the topmost group) requires the following. First you need to improve your [[opening play]]. Playing any reasonable looking moves during the initial phase of the game is enough for an orange player, but to compete with the reds, you need to [[Consistency|consistently]] play one of the top two or maybe three moves. Unfortunately, I don't know a good way to describe how to do this; I'm not convinced the necessary information can be verbalized. After that, you need to know the [[Minimax]] principle (described in the [[Advanced (strategy guide)|Advanced strategy guide]]).

Also you need a certain mindset, call it [[willpower]] if you like, to move towards the top ranks. You have to try to hold onto every little [[Hex (board element)|hex]] the way a miser hoards gold pieces and you have use every optimization you can no matter how minor it may seem. The most useful optimizations, tricks, and special situations that I've learned so far are included in the Advanced strategy guide. But surely there are other things out there waiting to be discovered.

== See also ==
* [[Basic (strategy guide)]]
* [[Advanced (strategy guide)]]

[[category:Intermediate Strategy]]

Computer Hex

2009-11-09T23:02:15Z

Roland Illig: /* Articles */ typo

This article enumerates diverse ways to exploit [[Hex]] with a computer.

== AI techniques used in Hex ==

*[[Minimax (computer)|Minimax]] and alpha-beta search were used by [[Queenbee]].
*[[UCT]] is used in MoHex.

== Programs with AI ==

There are several computer programs which play Hex.

=== Available programs ===

* The currently strongest available Hex program is [[Six]] by [[Gábor Melis]], running on Linux or Unix or Windows.
* The second strongest program available is [[Hexy]], running on Microsoft Windows. Hexy was the first program to use [[virtual connection]]s and was champion of the 5th Computer Olympiad in 2000.
* [http://www.cs.ualberta.ca/~queenbee/ Queenbee] by [[Jack van Rijswijck]] finished second that year.
* An iPhone app also named [[Hexy (iPhone)|Hexy]] (no relation), released in November 2008, offers an AI opponent; the AI appears to be a custom design and hasn't been rated.
* A second iPhone app named '''Hexatious''' released in August 2009, appears to offer a stronger AI than the iPhone Hexy app (in particular, Hexatious easily beats the other iPhone app in head-to-head competition).
* An online Java AI called [http://www.mattesmedjan.se/hexilla/ Hexilla] by Jonatan Rydh, released in October 2009.

=== Unavailable programs ===

* [[Wolve]] is currently the best Hex program. It is the gold medallist of 2008 Computer Olympiads.
* [[MoHex]] is a [[UCT|UCT-Monte Carlo]] Hex program developed at the [[University of Alberta]] by Philip Henderson, assisted by Broderick Arneson and Ryan Hayward
* [[Mongoose]] by [[Yngvi Björnsson]], [[Ryan Hayward]], Mike Johanson, Morgan Kan, and Nathan Po.

== Non playing programs ==

=== Front End ===
* [[HexGui]] is a graphical user interface designed by "ab", mostly used as a front end to play against Six. It is possible however to play against other programs that can communicate via [[GTP]]. It can be downloaded on "ab"'s web [http://mgame99.mg.funpic.de/havannah.php page].

=== Reviewing and Editing Programs ===

* [http://canyon23.net/jgame/README_hex.html JHex] by Kevin lets you analyse a game, and databases of games.
* [http://www.drking.plus.com/hexagons/hex/khex.html KHex] by David King is a tool for reviewing games. Very well suited for sharing commented games (it exports games in [[Smart Game Format]]!)

== External link==

=== Articles ===

*Anshelevich, Vadim V. [http://home.earthlink.net/~vanshel/VAnshelevich-ARTINT.pdf A hierarchical approach to computer Hex].
*van Rijswijck, Jack. [http://home.fuse.net/swmeyers/y-hex.pdf Search and evaluation in Hex].
*Rasmussen, Rune K. and Maire, Frederic D. and Hayward, Ross F. (2006) [http://eprints.qut.edu.au/5121/1/5121_1.pdf A Move Generating Algorithm for Hex Solvers].
*Rasmussen, Rune K. (2008) [http://eprints.qut.edu.au/18616/1/01Thesis.pdf Algorithmic approaches for playing and solving Shannon games] (PhD Thesis).

== See also ==
[[History of computer Hex]]

The [[ICGA|International Computer Games Association]] also has some [http://www.cs.unimaas.nl/icga/games/hex/ information on Hex]. They organize an annual [[Computer Olympiad]], which also covers Hex.

[[category:Computer Hex]]

Edge template IV1b

2009-09-24T17:05:00Z

Roland Illig:

==The edge template IVb==

<hex> R4 C8
Sa1 Sb1 Sc1 Sd1 Vf1 Sh1
Sa2 Sb2
Sa3 Se3
</hex>

Red has two threats using [[defending against intrusions in template 1-IIIa|template III-1-a]]:

<hex> R4 C8
Sa1 Sb1 Sc1 Sd1 Pe1 Vf1 Sh1
Sa2 Sb2 Pc2 V1d2 Pe2
Sa3 Pb3 Pc3 Pd3 Se3
Pa4 Pb4 Pc4 Pd4
</hex>and

<hex> R4 C8
Sa1 Sb1 Sc1 Sd1 Vf1 Pg1 Sh1
Sa2 Sb2 Pf2 V1g2 Ph2
Sa3 Se3 Pf3 Pg3 Ph3
Pe4 Pf4 Pg4 Ph4
</hex>
These moves lead to easy direct connection. Because there is no common [[hex (board element)|hex]] used in both threats, Blue cannot prevent Red to link to the bottom.

== See also ==

[[Multiple threats]]

[[category:edge templates]]

Edge template III1b

2009-09-24T17:04:24Z

Roland Illig:

==The edge template III-1-b==

<hex> R3 C5
Sa1 Sb1 Vd1
Sa2
Sc3</hex>

Red has two main threats:
<hex> R3 C5
Sa1 Sb1 Pc1 Vd1
Sa2 V1b2 Pc2
Pa3 Pb3 Sc3 </hex>
and

<hex> R3 C5
Sa1 Sb1 Vd1 Pe1
Sa2 Pd2 V1e2
Sc3 Pd3 Pe3</hex>

These moves lead to easy direct connection. Because there is no common [[hex (board element)|hex]] used in both threats, Blue cannot prevent Red to link to the bottom.

== See also ==

[[Multiple threats]]

[[category:edge templates]]

Defending against intrusions in template 1-IIIa

2009-09-24T17:03:53Z

Roland Illig:

== The edge template III-1-a ==

This template is also known under the name ziggurat.

<hex> R3 C4
Sa1 Sb1 Vc1
Sa2</hex>

Red has two main threats:
<hex> R3 C4
Sa1 Sb1 Vc1
Sa2 V1b2
Pa3 Pb3 </hex>
and

<hex> R3 C4
Sa1 Sb1 Vc1 Pd1
Sa2 Pc2 V1d2
Pc3 Pd3</hex>

These moves lead to easy direct connection. Because there is no common [[hex (board element)|hex]] used in both threats, Blue cannot prevent Red to link to the bottom.

== See also ==

[[Multiple threats]]

[[category:edge templates]]