HexWiki - User contributions [en]

Rules

2012-11-03T17:11:09Z

Roland Illig (Admin): /* Playing the game */ added an example

== 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]].

Forcing move

2012-11-03T13:18:19Z

Roland Illig (Admin): /* Breaking edge templates via forcing moves */ added move numbers

A '''forcing move''' is a move that makes a threat that your opponent must reply to on their next [[turn]]. Common forcing moves include playing in one of the [[Empty hex|open hex]]es in a two-chain (threatening to break the link), intrusion into an [[edge template]], or [[threat]]ening 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 (player)|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 (player)|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 edge|bottom]] and is of critical importance.

Red continues by playing another [[forcing move]] at g7. The only move that stops this piece from immediately [[connection|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 Ve8 He7 Vg7 Hf9 Vf8</hex>

The group of red pieces near the bottom are connected to the bottom edge. These pieces are connected via [[chain|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 [[Double threat|in two distinct ways]].)''

In general terms, you have three options when responding to a forcing move in a 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 [[red|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 [[Edge template IIIa|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 edge|right]].

<hex>R9 C9 Q1 Hc3 Hd3 He3 Hf2 Hg1 Hg3 Vd7 Ve6 Ve5 Ve4 Vf3 Vh5 N:on Vh2 Hg2 Vi3</hex>

== Using forcing moves to steal territory ==

I'll define [[territory]] to be the number of [[empty hex]]es adjacent to your pieces. By playing a forcing move in one of the empty hexes in a two-chain, a player can [[Stealing territory|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 hexes). Suppose Red makes the forcing move at the indicated hex and Blue [[Saving a connection|saves the link]].

<hex>R5 C5 Hc2 Hb4 Vd2 Vd3 Vb3 Hc3</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.

[[category:strategy]]

Advanced (strategy guide)

2012-11-03T13:06:04Z

Roland Illig (Admin): /* Third row ladder to a3 and its symmetric analogues */ added move numbers

== Advanced edge templates ==
=== Template IVc ===

<hex>R4 C4 Q1 1:BBRR 2:B_+_ 3:B**_ 4:_+__</hex>

This is a two-piece template and is useful for squeezing edge connections and ladder escapes into relatively small regions. Also, many players are unaware of it. Red's main threats are the two-chained connections via b3 or c3 (marked '*'). So the only strong defense is playing at c2 or b4 (marked '+').

==== Solution to intrusion at b4 ====

<hex>R4 C4 Q1 1:BBRR 2:B 3:B MH Mb4 Md3 Md2 Mb3</hex>

If Blue intrudes at b4, Red responds with d3, which is connected to the edge, so the blue move on d2 is forced.
Now b3 is a double threat for connecting either to the edge or to the forcing move at d3.
It is also possible to reverse the order of Red2 and Red4.

==== Solution to intrusion at c2 ====

<hex>R4 C4 Q1 1:BBRR 2:B 3:B MH Mc2 Mb3 Mb2 Md2 Mc4 Mc3</hex>

If Blue intrudes at c2, then Red responds with b3; b3 is connected to the edge via template II and threatens a direct connection via b2. So b2 by Blue is forced. Then Red plays at d2. Red threatens to extend d2 to template II at c3 and d3, and threatens to two-chain from d2 to the edge at c4. The only hex that is in the overlap of all these threats is c4 thus, Blue is forced to play at c4. Then Red plays at c3 completing the connection.

=== [[Defending_against_intrusions_in_template_1-Va|Template Va]] ===

<hex>R6 C10 Q1 1:BBBBBBRRBB 2:BBBBB_R_BB 3:BBBB_____B 4:BB 5:B +f4 +d6 +f6</hex>

If Blue intrudes in the template at any hex besides the three marked '+', Red makes a move that reduces the situation to a closer template.

Note that template Va occurs in a mirror-image form (in the mirror image form, the three hexes on the 5th row (from the bottom) are shifted over 1 hex to the G, H, and I columns). It may seem that this template is very strong because it reaches 5 rows into the board but it rarely occurs because of the huge size of the template; the template requires 31 empty hexes and 10 hexes along an edge — the entire edge on the 10x10 board!

Furthermore, the large perimeter makes it more vulnerable to encroaching adjacent plays and forcing moves. Additionally, template area surrounds the 5th row piece on both "shoulders" so that non-overlapping plays from the 5th row piece can occur in only two directions.

=== Template Vb ===

<hex>R6 C10 Q1 1:BBBBBBRBBB 2:BBBBBRRBBB 3:BBBB___BBB 4:BBB_____BB 5:BB______BB 6:B_______BB +f3 +e5</hex>

If the horizontal player Blue intrudes in the template at any hex besides the two marked '+', Red makes a move that reduces the situation to a closer template.

==== Solution to the intrusion at f3 ====

There are several solutions but the simplest is to respond with g3. Blue's only play to stop the immediate connection is f5. Then Red plays e4 yielding

<hex>R6 C10 Q1 1:BBBBBBRBBB 2:BBBBBRRBBB 3:BBBB___BBB 4:BBB_____BB 5:BB______BB 6:B_______BB MB Mf3 Mg3 Mf5 Me4</hex>

The e4 piece is connected to the bottom via a 3rd row template and e4 is connected to the other group of red pieces through e3 and f4. Thus, the connection is complete.

==== Solution to the intrusion at e5 ====

Red's best response is g4. This piece is connected to the bottom via a 3rd row template and hence Blue must block at g3. Red then plays e4 yielding

<hex>R6 C10 Q1 1:BBBBBBRBBB 2:BBBBBRRBBB 3:BBBB___BBB 4:BBB_____BB 5:BB______BB 6:B_______BB MB Me5 Mg4 Mg3 Me4</hex>

The e4 piece threatens to connect to the bottom in two non-overlapping ways, to d5 and to g4 (through f4). Hence the connection is unstoppable.

Unlike template Va, this template is not a rare occurrence and many hex players are not familiar with it.

== Advanced templates as ladder escapes ==

Templates IVc and Vb are valid escapes for row 2, row 3, and row 4 ladders. Template Va is not a valid ladder escape.

Exception: Template Vb is not valid for 3rd and 4th row ladders coming from the right side in the above diagram if the Horizontal player has a piece at h3. For the horizontal player to defeat the 3rd row ladder in this case, connecting to h3 must provide a strong threat that the vertical player needs to respond to.

Note: The unique way to win with template Vb and a 2nd row ladder is as follows. As soon as your head ladder piece intrudes on the template, your very next move must be to two-chain up to the 3rd row (this is true no matter which side of the template you are entering from). Then you break off the ladder (this piece will be connected to the edge via a smaller edge template).

== The minimax principle ==
(See also the page [[Minimax]])

Suppose you have multiple ways of establishing/maintaining a connection to an edge. A move that maintains as strong a connection as possible is not preferable to other connection moves because you only need to get some connection; you don't win extra points by connecting more strongly.

In fact it is generally better to play a move that maintains as ''weak'' a connection as possible; the reason being that such a piece may help you extend the connection towards the opposite edge. This principle is sometimes called "mini-maxing."

The idea behind the term is that you are playing a move that maintains a minimal connectivity in one direction while building up (i.e. maximizing) your strength in the other direction. I'll illustrate this with a couple of positions from my games. (Note that this principle applies equally well when establishing/maintaining a connection to ''a group of pieces''.)

=== Example 1 ===
<hex>R10 C10 Q1 Ma3 Mf5 Mc6</hex>

My opponent, Blue played the minimax move f4. This move maintains a minimal strength connection to the left while building up strength to the right; in fact the f4-f5 group is almost connected to the right edge via template Vb. I responded with my own minimax move d5 (d6 is the other minimax option) yielding the following position.

<hex>R10 C10 Q1 Va3 Hf5 Vc6 MH M4f4 Md5</hex>

d5 maintains a minimal strength connection to the bottom while maximizing my strength to the top. (d6 would have maintained a minimal strength connection to the top while maximizing my strength to the bottom.) A move that is even stronger towards the top, such as d4, would be a mistake. My opponent could then block at the bottom with c7, which is connected to the left edge via a 3rd row template and which threatens to link up with the central group. If I try to stop the connection to the central group with e6, my opponent responds with d5 yielding the following position.

<hex>R10 C10 Q1 Va3 Hf5 Vc6 Hf4 M5d4 Mc7 Me6 Md5</hex>

d5 is connected to the central group via a 2-chain and the combined threats c5 and d6 guarantee a connection to the left edge (a7 is defeated by c5, b5, b6, a6, b7, a8, b9). I would be in dire straits as the central pair f4-f5 is almost connected to the right edge.

Now back to the game; after my minimax move d5, I can safely meet c7 with e6. Yielding

<hex>R10 C10 Q1 Va3 Hf5 Vc6 Hf4 Vd5 MH M6c7 Me6</hex>

In fact, the c7, e6 sequence occurred in the actual game. I eventually won after a close hard fought battle.

=== Example 2 ===
<hex>R10 C10 Q1 Va3 Vc6 Vb8 Vc8 Vd8 Ve8 Vg6 Vg7 Vg8 Hf5 Hf7 Hf8 He9 Hd9 Hc9 Hb9 Hd7</hex>

In this position, I was the vertical player and was expecting f6 to which h4 would give me an excellent position (with best play, this position would in fact be winning though this is not obvious). Instead my opponent played the excellent minimax move f4. This move fights in both directions and is in fact a killer move. I can't block the f4-f5 pair from the right due to the forking ladder escape at h9. Thus, I must meekly submit to the forcing sequence f6, e7, e6, d5 yielding

<hex>R10 C10 Q1 Va3 Vc6 Vb8 Vc8 Vd8 Ve8 Vg6 Vg7 Vg8 Hf5 Hf7 Hf8 He9 Hd9 Hc9 Hb9 Hd7 MH Mf4 Mf6 Me7 Me6 Md5</hex>

The game is over. The f4-f5 pair is connected to d5 which in turn threatens to connect to left in two non-overlapping ways, c5 (a 3rd row template) and d6, hence the pair is connected to the left. If I try to block at the right, the best I can do is yield a ladder (e.g. h4, h3, j2, i3 and H has a second row ladder) and then the forking ladder escape at h9 wins the game.

=== Example 3 ===
In the next example, I am the horizontal player and it is my move.

<hex>C10 R10 Q1 Va2 Vb5 Vb8 Vc7 Vd6 Vd5 Vf4 Hc6 Hc5 Hd4 He4 He5 Hf5</hex>

Most hex players would probably connect to the left side with a7 (or b6 or b7). Despite its apparent necessity, this move actually loses (against best play). Instead I played the winning minimax move d3! By adding a second non-overlapping connection threat to the left, my group of pieces maintains a connection to the left. And despite its modest appearance, d3 also helps out on the right and in fact guarantees a winning connection from f5 to the right by defeating one of the main potential blocking plays.

<hex>C10 R10 Q1 Va2 Vb5 Vb8 Vc7 Vd6 Vd5 Vf4 Hc6 Hc5 Hd4 He4 He5 Hf5 MH Md3</hex>

E.g. suppose V tries to block the f5 piece from the right as follows.

<hex>C10 R10 Q1 Va2 Vb5 Vb8 Vc7 Vd6 Vd5 Vf4 Hc6 Hc5 Hd4 He4 He5 Hf5 Hd3 M2g5 Mg4 Mi3 Mi2</hex>

4 at h4 would also be possible. Now I have a forced winning ladder down row 2, completing the win.

<hex>C10 R10 Q1 Va2 Vb5 Vb8 Vc7 Vd6 Vd5 Vf4 Hc6 Hc5 Hd4 He4 He5 Hf5 Hd3 Vg5 Hg4 Vi3 Hi2 Mh3 Mh2 Mg3 Mg2 Mf3 Mf2 Me3 Me2</hex>

This line clearly shows the usefullness of d3. If I hadn't played d3 (playing a7 instead, for instance), the vertical player could continue d3, d2, c3, c2, b3, b2, a3 and eventually winning with best play (considerable deep analysis is needed to show this).

<hex>C10 R10 Q1 Va2 Vb5 Vb8 Vc7 Vd6 Vd5 Vf4 Hc6 Hc5 Hd4 He4 He5 Hf5 Ha7 Vg5 Hg4 Vi3 Hi2 Vh3 Hh2 Vg3 Hg2 Vf3 Hf2 Ve3 He2 Md3 Md2 Mc3 Mc2 Mb3 Mb2 Ma3</hex>

Minimax moves are not always "parallel" moves. The principle of maintaining a minimal amount of connectivity in one direction while maximizing your strength in the opposite direction is more general than that.

=== Example 4 ===
The final example from a game of mine illustrates non-parallel mini-max moves. I was the vertical player and opened with 1. a3 and my opponent responded with 1... e4 yielding the following position.

<hex>C10 R10 Q1 V1a3 H2e4</hex>

I played the minimax move 2. f5 yielding

<hex>C10 R10 Q1 Va3 He4 V3f5</hex>

By connecting as far away as possible from the top, I increase my strength towards the bottom. (i.e. I am maintaining a minimal strength connection to the top while maximizing my strength towards the bottom). Before playing such a move, I have to verify that my opponent can't stop me from reaching the top. I could meet the attempted block with 2...g4 or 2...h2 by getting a third row ladder (2...g4 3.f4 g2 4.f3, etc. or 2...h2 3.g3 g2 4.f3, etc.), laddering down to e3, and then playing b4 (how to play a third row to a3 is described in a later section). I would be happy with such a line. My opponent however played the excellent e3. This move takes away the ladder, hence forcing me to reconnect to the top, while at the same time increasing his strength to the left.

<hex>C10 R10 Q1 Va3 He4 Vf5 H4e3</hex>

Here I played the minimax move g4. g4 has the potential to help block my opponent from going across the bottom of the board (e.g. Blue e7, Red f7, Blue f6, Red h5 and now g4 is helping out) or equivalently helps me to connect downwards on the right. I.e. g4 maintains a minimal strength connection towards the top while maximizing my strength towards the bottom. Note that a stronger move towards the top such as g3 does not have the same potential to help out towards the bottom. This potential may seem remote but in fact I would not have won the game without it! The rest of the game does not illustrate minimaxing but it is instructive nevertheless.

'''See [[Glenn_C._Rhoads_vs._unknown]]'''

== Special situations, tricks, etc. ==

=== Reconnecting edge template IIIa after an intrusion ===

<hex>R4 C10 Q1 Ve2 Hd3 Pf2 Se3</hex>

In this diagram, suppose you are Red and Blue has just played d3 intruding upon the third row template connecting your e2 to the bottom. Most hex players would reconnect with e3 without giving it much if any thought, yet there are three distinct ways to reconnect and there is often a reason for preferring one over the other.

A second way for Red to reconnect is to play f2 — the hex f2 and the empty hexes g2,e3,f3,g3,d4,e4,f4, and g4 form edge template IIIa; hence f2 has an unbreakable connection to the bottom and f2 is connected to e2.

The potential advantage of reconnecting with f2 over e3 is that it is easier to connect other pieces to the the group e2-f2 than to the group e2-e3 (e.g. h1 is a two-chain away from f2 but is not a two-chain away from either e2 nor e3). The extra connection possibilities can make a critical difference. For example, consider the following position with Red to move.

<hex>R9 C9 Q1 Vg2 Vf3 Ve4 Vd5 Vd6 Vh3 Vh4 Vf7 Hi4 Hc6 Hb8 Hc8 He6 Hf6 Hg6</hex>

Red can win by laddering 1. d7 d8 2. e7. Suppose instead Red plays 1.h5 intruding on the g6 edge template. If Blue reconnects with h6, then Red would have nothing else to do except play the winning line. So Blue reconnects with g7 making the win tougher. (Red could still win by d7, d8, e7, e9, f8, f9, h8! — a forking ladder escape which decides the issue).

Now suppose that Red again intrudes on the edge template with 2. h6. Now the game continues 2...g8 (again reconnecting by playing parallel to the edge) 3. h7 (persistent) h8, 4. d7 d8, 5. e7 e9! and now Blue has an unbreakable winning chain at the bottom. By reconnecting with the parallel moves instead of the direct reconnection, Blue's group had a new way to connect to the left and this extra possibility turned a defeat into a win.

So is it always better to reconnect with the parallel move? No!! Sometimes the parallel reconnection can lose the game while the simple direct connection wins! The potential weakness of the parallel reconnection is that your opponent might then be able to use a double threat to defeat the edge connection. For example, consider the following position with Red to move.

<hex>R9 C9 Q1 Vh3 Vg2 Vf3 Ve4 Vd5 Vd6 Hc6 Hb8 Hc8 He6 Hg5 Hi3</hex>

With best play Blue wins, so Red tries 1. h4. If Blue responds with the direct reconnection h5, then the win is assured and Red may as well resign. Suppose instead that Blue reconnects with 1... g6. Then Red can respond with 2.h7! — this forking ladder escape is a killer. Red now has two disjoint winning threats, laddering from d7 to h7 and play i5 (This double two-chain cutoff threat occurs in situations besides cutting off third row edge templates. It is well worth being familiar with this idea.). Blue cannot stop them both so Red wins.

But this doesn't exhaust the reconnection possibilities. There is a third way to reconnect; a way that most players don't seem to discover.

<hex>R4 C10 Q1 Ve2 Hd3</hex>

Again starting at the initial position in this section, Red's e2 piece is connected to the bottom via edge template IIIa and Blue intrudes upon it with d3. In addition to e3 and f2, Red can reconnect with the surprising f1!

<hex>R4 C10 Q1 Ve2 Hd3 Vf1</hex>

Red is threatening to connect e2-f1 to the bottom with e3. If Blue tries to block this with e3, then Red can reconnect by playing g2. g2 is connected to the bottom via template IIIa (Blue's e9 piece is just outside of this template) and h3 connects to f1 via a two-chain.

But what if Blue blocks with e4 instead of e3? (note the e4 is within the g2 piece's edge template). Then Red can still reconnect by playing as follows. 1. e3 d4 (forced) 2. g3 f3 (forced again) 3.g2 ending up with the following position.

<hex>R4 C10 Q1 Ve2 Hd3 Vf1 MH Me4 Me3 Md4 Mg3 Mf3 Mg2</hex>

How does this method compare to the previous two? Compared to the parallel reconnection, it is quite a bit more susceptible to forking plays and plays that encroach upon the increased area that is needed to reconnect, but by playing away from the edge, you have even more potential to connect the edge group towards the opposite edge. Sometimes the extra connection possibilities generated by playing away from the edge is exactly what is needed.

For example consider the beautiful solution to the following position which makes use of what I call "Tom's Move" (I wish I could take the credit for its discovery but the original over the board play was found by Tom239 on _Playsite_, he was at the orange level at the time!). The position below is a slight modification of one constructed by Kevin O'Gorman, the maintainer of the Ohex data base).

<hex>R10 C10 Q1 Va2 Va3 Va4 Va5 Va6 Va7 Va8 Va9 Ha10 Hb2 Hb3 Hb4 Hb5 Hb6 Hb7 Hb8 Vc6 Hc7 Vd5 Hd6 Vd7 Ve4 He5 Vf3 Hf4 Vg2 Hg3 Vh1 Hh2 Hi2</hex>

It is Red's move. To win, Red must connect his a9 piece to bottom. To do this, Red must make some ladder escape that additionally must somehow use the d7 piece to threaten another way to connect to the ladder. This looks impossible but yet there is a way. Red can win by starting with 1.b9 b10 2.c9 c10 3.f8!! (f8 is "Tom's Move").

<hex>R10 C10 Q1 Va2 Va3 Va4 Va5 Va6 Va7 Va8 Va9 Ha10 Hb2 Hb3 Hb4 Hb5 Hb6 Hb7 Hb8 Vc6 Hc7 Vd5 Hd6 Vd7 Ve4 He5 Vf3 Hf4 Vg2 Hg3 Vh1 Hh2 Hi2 Mb9 Mb10 Mc9 Mc10 Mf8</hex>

This brilliant move is the only way to win (it is, essentially, [[Tom's move]]). 3.g7 is defeated only by 3...d9 and 3.d9 d10 4.g7 is defeated only by 4...f8 (it takes a ''lot'' of analysis to demonstrate these claims). Blue's only good attempt is to intrude on the edge template with 3... e9. But Red can defeat this by reconnecting with 4.g7! (this is what Red had in mind when playing 3.f8!!)

<hex>R10 C10 Q1 Va2 Va3 Va4 Va5 Va6 Va7 Va8 Va9 Ha10 Hb2 Hb3 Hb4 Hb5 Hb6 Hb7 Hb8 Vc6 Hc7 Vd5 Hd6 Vd7 Ve4 He5 Vf3 Hf4 Vg2 Hg3 Vh1 Hh2 Hi2 Vb9 Hb10 Vc9 Hc10 Vf8 MH Me9 Mg7</hex>

Now f8-g7 has an unbreakable connection to the bottom and Red threatens two distinct ways of connecting this group back to the group containing c9; Red threatens f6, double two-chaining between d7 and g7, and Red threatens e8 two-chaining to c9. Blue's only possible defense is the forcing move 4...d8. This interferes with the immediate connection threat between c9 and f8, and it prepares to meet the f6 threat with c8 cutting off d7 from c9. But this move is still not sufficient because after 4...d8, Red can win with 5.d9 d10 (forced) 6.e8.

In practice, you can think of the parallel reconnection as your "standard" response (more often than not, it is the correct choice). But if the potential threat to cut off the parallel play from the edge is serious, then go with the direct reconnection. The "away" reconnection entails a substantially increased risk of being cut off from the edge but if you can see that it will be safe or if you need the stronger connection possibilities towards the opposite edge, then go with the "away" connection.

=== Third row ladder to a3 and its symmetric analogues ===
(See also the page [[a3 escape trick]])

The following position is from one of my games.

<hex>R10 C10 Q1 Hg2 Vi2 He3 Hg3 Hb4 Hc4 He4 Vf4 Vg4 Vb5 Vc5 Ve6 Vf6 Hh10</hex>

I am Blue and it is my move. Red's e6-f6(-f4-g4) group is connected to bottom via template Vb. Red's i2 piece is connected to the top via edge template II. In order to stop these two groups from connecting to each and completing a win, I must start laddering down column H. So I ladder down to h6 forcing Red to follow down column I to i6 yielding the following position.

<hex>R10 C10 Q1 Hg2 Vi2 He3 Hg3 Hb4 Hc4 He4 Vf4 Vg4 Vb5 Vc5 Ve6 Vf6 Hh10 N:on Hh3 Vi3 Hh4 Vi4 Hh5 Vi5 Hh6 Vi6</hex>

My h10 piece is ''not'' a valid ladder escape. If I ladder all the way down to h10, then Red follows down to i8 and his response to h9 is not i9 but j9!

<hex>R10 C10 Q1 Hg2 Vi2 He3 Hg3 Hb4 Hc4 He4 Vf4 Vg4 Vb5 Vc5 Ve6 Vf6 Hh10 Hh3 Vi3 Hh4 Vi4 Hh5 Vi5 Hh6 Vi6 N:on Hh7 Vi7 Hh8 Vi8 Hh9 Vj9</hex>

Red has a winning chain on the right side. You might think I could win by instead laddering down one more hex, and then double two-chain to the h10 piece yielding the following position.

<hex>R10 C10 Q1 Hg2 Vi2 He3 Hg3 Hb4 Hc4 He4 Vf4 Vg4 Vb5 Vc5 Ve6 Vf6 Hh10 Hh3 Vi3 Hh4 Vi4 Hh5 Vi5 Hh6 Vi6 N:on Hh7 Vi7 Hg9</hex>

This may appear to settle the matter in my favor but in actuality, Red has a winning position! Red can win by 1. h8 (h9 also works but h8 is slightly more deceptive). If I respond by saving the link, i.e. by 1...g8, then Red wins by playing 2.h9 g10 (forced) 3. j9.

<hex>R10 C10 Q1 Hg2 Vi2 He3 Hg3 Hb4 Hc4 He4 Vf4 Vg4 Vb5 Vc5 Ve6 Vf6 Hh10 Hh3 Vi3 Hh4 Vi4 Hh5 Vi5 Hh6 Vi6 Hh7 Vi7 Hg9 N:on Vh8 Hg8 Vh9 Hg10 Vj9</hex>

Red has an unbreakable winning chain down the right. Instead it is better for me to respond to Red's 1.h8 with 1...h9. My g9-h9-h10 group is now solidly connected to the right but Red can continue 2.g8 and I cannot stop g8 from connecting to the bottom because of the help provided by Red's e6-f6 pieces (work it out!)

In the initial position I cannot afford to ladder down any farther than g6. If I ladder down one more hex, I lose against best play no matter what. If there are no other pieces in the area, as is the case here, then the strongest way to play it is to ladder down one hex short of the hex that could double two-chain to the "almost-escape" piece, and then two chain up from the almost-escape piece which in our present case yields the following position.

<hex>R10 C10 Q1 Hg2 Vi2 He3 Hg3 Hb4 Hc4 He4 Vf4 Vg4 Vb5 Vc5 Ve6 Vf6 Hh10 Hh3 Vi3 Hh4 Vi4 Hh5 Vi5 Hh6 Vi6 N:on Hg9</hex>

Red has three tries to stop the connection between the h6 and g9 pieces.

* g8 is defeated by continuing the ladder down (try it!).
* h7 and h8 are best met by f8 (double two-chaining in the same direction).
* Meeting the play h8 with g8 (connecting up to h6) doesn't work for the same reason that laddering down to h7 and double two-chaining to h10 doesn't work (work it out and you should see what I mean).

Also, note that Red's attempt h9 is of no consequence. Against h9 you should save the link with g10 and then again meet either h7 or h8 with f8.

In the actual game my opponent played h7 and I responded with f8. f8 threatens to connect with with h6 through g7. So my opponent played g7 to which I responded with f7. Again this threatens a winning connection from f7 to h6 through g6. So my opponent played g6 and I responded with c9 with a winning position.

<hex>R10 C10 Q1 Hg2 Vi2 He3 Hg3 Hb4 Hc4 He4 Vf4 Vg4 Vb5 Vc5 Ve6 Vf6 Hh10 Hh3 Vi3 Hh4 Vi4 Hh5 Vi5 Hh6 Vi6 Hg9 N:on Vh7 Hf8 Vg7 Hf7 Vg6 Hc9</hex>

Further play no longer concerns the topic under discussion but the remaining moves were d9, e7, d7, d8, b9, c8, a8, b8, a9, b7, a7, d6, resigns. My opponent doesn't need to see g8, f9, h9, g10, j9, i8

The key play of two-chaining up from the escape piece is also useful in another common type of third row ladder position. For example, consider the following position with the vertical player to move.

<hex>R10 C10 Q1 He2 Vi2 Va3 Hf3 Hc4 Vd4 He4 Hf4 Vh4 Vi4 Vc5 Hd5 Hf5 Hh5 Vi5 Vc6 Hf6 Hg6 Hi6 Vc7 Hd7 He7 Vf7 Hg7 Vh7 Vc8 Vd8 Ve8 Hg8 Hh8 Hb9 Vc9</hex>

Red has a chain running from the bottom at c9 up to d4. The only way Red can win is to connect this group to the top. Red can ladder d3, c3, b3 but as we saw earlier, the a3 piece is not a valid ladder escape. But Red can still win by two-chaining from a3 to b4.

<hex>R10 C10 Q1 He2 Vi2 Va3 Hf3 Hc4 Vd4 He4 Hf4 Vh4 Vi4 Vc5 Hd5 Hf5 Hh5 Vi5 Vc6 Hf6 Hg6 Hi6 Vc7 Hd7 He7 Vf7 Hg7 Vh7 Vc8 Vd8 Ve8 Hg8 Hh8 Hb9 Vc9 N:on Vb4</hex>

This threatens a winning connection to c5 through b5. If Blue blocks this with b5, then Red plays the ladder because now the pair a3-b4 are a valid ladder escape. If instead Blue blocks off the ladder with say c3, then Red wins with the line b5, b3, a4 (forced), b1, d2!

<hex>R10 C10 Q1 He2 Vi2 Va3 Hf3 Hc4 Vd4 He4 Hf4 Vh4 Vi4 Vc5 Hd5 Hf5 Hh5 Vi5 Vc6 Hf6 Hg6 Hi6 Vc7 Hd7 He7 Vf7 Hg7 Vh7 Vc8 Vd8 Ve8 Hg8 Hh8 Hb9 Vc9 Vb4 N:on Hc3 Vb5 Hb3 Va4 Hb1 Vd2</hex>

d2 is a forking ladder escape; it threatens d3 and it provides an escape to the 2nd row ladder starting with b2. Blue cannot stop both winning threats with a single move, thus Red wins.

a3/j8 is a common opening move. If you frequently play it or play against somebody who does, then you will run into these 3rd row ladder situations and hence, it will be beneficial to learn how to play them.

=== The parallel ladder escape ===
(See also the page [[Parallel ladder]])

Consider the following position with Red to play.

<hex>R10 C10 Q1 Hc1 Vd2 Vd3 He3 Vf3 Vd4 Ve4 Hf4 Hg4 Ve5 Vc6 Vd6 He6 Hi6 Hc7 Vd7 Ha8 Hb8 Vc8 Hd8 Hb10</hex>

All of Red's pieces form a connected group. This group is connected to the top. At the bottom, Red has a second row ladder with no possible escape on the left. The potential escapes on the right are inadequate. For example, suppose Red ladders to f9. Then tries to escape with 5.h9 g9 6.h8 g8 7.h7 f7.

<hex>R10 C10 Q1 Hc1 Vd2 Vd3 He3 Vf3 Vd4 Ve4 Hf4 Hg4 Ve5 Vc6 Vd6 He6 Hi6 Hc7 Vd7 Ha8 Hb8 Vc8 Hd8 Hb10 Vc9 Hc10 Vd9 Hd10 Ve9 He10 Vf9 Hf10 Vh9 Hg9 Vh8 Hg8 Vh7 Hf7</hex>

Now Red's only reasonable try is 8.g7 f8. Now 9.g6 loses to 9...f5 and 9.h5 loses to the forcing sequence 9...g6 10.h6 h4 11.g5 f5. All the other escape attempts likewise fail. Is Red done for?

No! Red can create a sufficient escape by making use of a parallel ladder. In the original position Red plays 1.e7. How can Blue stop Red from connecting to the bottom? d9 lets Red two-chain from e7 to f8 connecting to the bottom; e9 and e10 allow d9 which is connected to the bottom and threatens to connect to Red's big group through c9 and e8; d10 loses to e8, f9 (forced), c10; hence, Blue is forced to play the parallel ladder move 1...e8. It is simplest for Red to repeat this and ladder to f7 forcing the 2...f8 response.

<hex>R10 C10 Q1 Hc1 Vd2 Vd3 He3 Vf3 Vd4 Ve4 Hf4 Hg4 Ve5 Vc6 Vd6 He6 Hi6 Hc7 Vd7 Ha8 Hb8 Vc8 Hd8 Hb10 Ve7 He8 Vf7 Hf8</hex>

Now Red now goes back to the second row ladder and tries to escape. What have we gained by preceding this with the parallel ladder moves? When trying to escape, the threat to connect to d7-e7-f7 is stronger than the previous weak threat to connect to d7. This extra threat will let us push our escape chain farther up the board and in this case, just far enough to win the game.

Red's winning sequence is long but rather simple because every one of Blue's replies is forced. As before, Red ladders to f9 and escapes with 7. h9. Play continues 7...g9 8.h8 g8 9.h7 g7 10.h6 g6 11.h5. Red is threatening to play g5 with the double winning threats f5 and f6. But if Blue blocks this, say with 11...g5, then Red continues 12.i3 i2 13.h3 and 14.g3 completes the win.

I have managed to pull this trick off from one row farther back; i.e. with ladders on row 3 and 5 but this occurs far less frequently and you have to examine some additional defensive possibilities. Consider the following position.

<hex>R10 C10 Q1 Vd5 He5 Vd6 Ve6 Hb7 Vc7 Hd7 Hb9</hex>

Red has just played e6 trying the parallel ladder exccape. With the closer ladder on row 2, we saw that Blue was forced to respond with the parallel ladder play e7. But here Blue has two additional possibilities e8 and c9 (the only other possibility where Red doesn't have a way to force his group to connect to the bottom is c10. But Red can respond with f8 and now Blue has nothing better than e7, g6).

e8 yields a second row ladder after d8, e7, c8, c10, d9. The play c9 also leads to a second row ladder after the likely f7, f8, e8 (d9 is met by e7) d10. In the latter case, Red could again try the parallel ladder escape by playing g7. Of course, the existence of other pieces in the area can change the possibilities.

For whom who understand The parallel ladder escape !
This trick is useful only for ladder 2nd and 4th!

Consider the following position with Red to play and win. Red's has winning position even with a blue stones in h5 from the beginning.
<hex>R10 C10 Q1
Hc1
Vd2
Vd3 He3 Vf3
Vd4 Ve4 Hf4 Hg4
Ve5 Hh5
Vc6 Vd6 He6 Hi6
Hc7 Vd7
Ha8 Hb8 Vc8 Hd8

Hb10 </hex>

[[parallel ladder#A parallel ladder escape puzzle|The solution is 1.f8]]

Note from original author (Glenn C. Rhoads):
I realized that my example had this improved solution which ruins the example but I never got around to writing a correct example. The move 1.f8 is essentially what I call "Tom's Move" in the last example of the section "Reconnecting template IIIa after an intrusion." The parallel ladder escape is when you can push the escape up by using the threats to connect to each branch of the parallel ladder. You might think Tom's move does away with the need for the parallel ladder escape but this is not the case. If you take the above position and shift every piece one hex to the right, then Tom's move no longer works because after blue's intrusion, there is not enough room to reconnect this piece to the bottom by playing the "away" connection (see Blue's third option in the provided solution). Yet there is still enough room to potentially ladder escape up the third row from the right edge. The example has to be modified to make the parallel ladder escape work and be the only way to win. Also, there are cases where the ladder starts at the far left and you must push the parallel ladders to the right in order to avoid some centrally located pieces. After pushing past them, Tom's move can then work. Both ideas are useful but Tom's move seems to work more often than the parallel ladder escape.

Also, I did have one game where I managed to pull off a parallel ladder escape from rows 3 and 5! I wish I had saved the moves of the game. The position was much too complex for me to ever remember it.

As an aside, I recall the conventional wisdom that every chess book ever written has mistakes in it (not literally true but a chess book without an error is a rarity indeed; even most beginner chess books have mistakes in them). Perhaps a similar thing could be said about Hex. Both games are at times very difficult and complex where it is all too easy to make a mistake. Of course I had no such intention of providing supporting evidence by my mistaken example. There is another mistake in my advanced guide. In the fourth example in the mini-maxing section, my first mini-maxing play can be defeated! In the subsequent game, my opponent plays an excellent move which I believe would have given him a winning position had it been played in the opening (with this hint, can you find the move?). I didn't bother trying to come up with another example out of sheer laziness. I wanted an opening example where mini-maxing would upon a close examination of the subsequent game, make a more or less direct difference in the outcome of game. Most examples of mini-maxing in the opening help in a less direct extremely complex way. I was reluctant to spend the time to find a good example and to provide a detailed analysis of the subsequent game when it seemed unlikely that anybody would notice the problem!

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

[[category:Advanced Strategy]]

Advanced (strategy guide)

2012-11-03T13:00:49Z

Roland Illig (Admin): /* Example 4 */ added move numbers

== Advanced edge templates ==
=== Template IVc ===

<hex>R4 C4 Q1 1:BBRR 2:B_+_ 3:B**_ 4:_+__</hex>

This is a two-piece template and is useful for squeezing edge connections and ladder escapes into relatively small regions. Also, many players are unaware of it. Red's main threats are the two-chained connections via b3 or c3 (marked '*'). So the only strong defense is playing at c2 or b4 (marked '+').

==== Solution to intrusion at b4 ====

<hex>R4 C4 Q1 1:BBRR 2:B 3:B MH Mb4 Md3 Md2 Mb3</hex>

If Blue intrudes at b4, Red responds with d3, which is connected to the edge, so the blue move on d2 is forced.
Now b3 is a double threat for connecting either to the edge or to the forcing move at d3.
It is also possible to reverse the order of Red2 and Red4.

==== Solution to intrusion at c2 ====

<hex>R4 C4 Q1 1:BBRR 2:B 3:B MH Mc2 Mb3 Mb2 Md2 Mc4 Mc3</hex>

If Blue intrudes at c2, then Red responds with b3; b3 is connected to the edge via template II and threatens a direct connection via b2. So b2 by Blue is forced. Then Red plays at d2. Red threatens to extend d2 to template II at c3 and d3, and threatens to two-chain from d2 to the edge at c4. The only hex that is in the overlap of all these threats is c4 thus, Blue is forced to play at c4. Then Red plays at c3 completing the connection.

=== [[Defending_against_intrusions_in_template_1-Va|Template Va]] ===

<hex>R6 C10 Q1 1:BBBBBBRRBB 2:BBBBB_R_BB 3:BBBB_____B 4:BB 5:B +f4 +d6 +f6</hex>

If Blue intrudes in the template at any hex besides the three marked '+', Red makes a move that reduces the situation to a closer template.

Note that template Va occurs in a mirror-image form (in the mirror image form, the three hexes on the 5th row (from the bottom) are shifted over 1 hex to the G, H, and I columns). It may seem that this template is very strong because it reaches 5 rows into the board but it rarely occurs because of the huge size of the template; the template requires 31 empty hexes and 10 hexes along an edge — the entire edge on the 10x10 board!

Furthermore, the large perimeter makes it more vulnerable to encroaching adjacent plays and forcing moves. Additionally, template area surrounds the 5th row piece on both "shoulders" so that non-overlapping plays from the 5th row piece can occur in only two directions.

=== Template Vb ===

<hex>R6 C10 Q1 1:BBBBBBRBBB 2:BBBBBRRBBB 3:BBBB___BBB 4:BBB_____BB 5:BB______BB 6:B_______BB +f3 +e5</hex>

If the horizontal player Blue intrudes in the template at any hex besides the two marked '+', Red makes a move that reduces the situation to a closer template.

==== Solution to the intrusion at f3 ====

There are several solutions but the simplest is to respond with g3. Blue's only play to stop the immediate connection is f5. Then Red plays e4 yielding

<hex>R6 C10 Q1 1:BBBBBBRBBB 2:BBBBBRRBBB 3:BBBB___BBB 4:BBB_____BB 5:BB______BB 6:B_______BB MB Mf3 Mg3 Mf5 Me4</hex>

The e4 piece is connected to the bottom via a 3rd row template and e4 is connected to the other group of red pieces through e3 and f4. Thus, the connection is complete.

==== Solution to the intrusion at e5 ====

Red's best response is g4. This piece is connected to the bottom via a 3rd row template and hence Blue must block at g3. Red then plays e4 yielding

<hex>R6 C10 Q1 1:BBBBBBRBBB 2:BBBBBRRBBB 3:BBBB___BBB 4:BBB_____BB 5:BB______BB 6:B_______BB MB Me5 Mg4 Mg3 Me4</hex>

The e4 piece threatens to connect to the bottom in two non-overlapping ways, to d5 and to g4 (through f4). Hence the connection is unstoppable.

Unlike template Va, this template is not a rare occurrence and many hex players are not familiar with it.

== Advanced templates as ladder escapes ==

Templates IVc and Vb are valid escapes for row 2, row 3, and row 4 ladders. Template Va is not a valid ladder escape.

Exception: Template Vb is not valid for 3rd and 4th row ladders coming from the right side in the above diagram if the Horizontal player has a piece at h3. For the horizontal player to defeat the 3rd row ladder in this case, connecting to h3 must provide a strong threat that the vertical player needs to respond to.

Note: The unique way to win with template Vb and a 2nd row ladder is as follows. As soon as your head ladder piece intrudes on the template, your very next move must be to two-chain up to the 3rd row (this is true no matter which side of the template you are entering from). Then you break off the ladder (this piece will be connected to the edge via a smaller edge template).

== The minimax principle ==
(See also the page [[Minimax]])

Suppose you have multiple ways of establishing/maintaining a connection to an edge. A move that maintains as strong a connection as possible is not preferable to other connection moves because you only need to get some connection; you don't win extra points by connecting more strongly.

In fact it is generally better to play a move that maintains as ''weak'' a connection as possible; the reason being that such a piece may help you extend the connection towards the opposite edge. This principle is sometimes called "mini-maxing."

The idea behind the term is that you are playing a move that maintains a minimal connectivity in one direction while building up (i.e. maximizing) your strength in the other direction. I'll illustrate this with a couple of positions from my games. (Note that this principle applies equally well when establishing/maintaining a connection to ''a group of pieces''.)

=== Example 1 ===
<hex>R10 C10 Q1 Ma3 Mf5 Mc6</hex>

My opponent, Blue played the minimax move f4. This move maintains a minimal strength connection to the left while building up strength to the right; in fact the f4-f5 group is almost connected to the right edge via template Vb. I responded with my own minimax move d5 (d6 is the other minimax option) yielding the following position.

<hex>R10 C10 Q1 Va3 Hf5 Vc6 MH M4f4 Md5</hex>

d5 maintains a minimal strength connection to the bottom while maximizing my strength to the top. (d6 would have maintained a minimal strength connection to the top while maximizing my strength to the bottom.) A move that is even stronger towards the top, such as d4, would be a mistake. My opponent could then block at the bottom with c7, which is connected to the left edge via a 3rd row template and which threatens to link up with the central group. If I try to stop the connection to the central group with e6, my opponent responds with d5 yielding the following position.

<hex>R10 C10 Q1 Va3 Hf5 Vc6 Hf4 M5d4 Mc7 Me6 Md5</hex>

d5 is connected to the central group via a 2-chain and the combined threats c5 and d6 guarantee a connection to the left edge (a7 is defeated by c5, b5, b6, a6, b7, a8, b9). I would be in dire straits as the central pair f4-f5 is almost connected to the right edge.

Now back to the game; after my minimax move d5, I can safely meet c7 with e6. Yielding

<hex>R10 C10 Q1 Va3 Hf5 Vc6 Hf4 Vd5 MH M6c7 Me6</hex>

In fact, the c7, e6 sequence occurred in the actual game. I eventually won after a close hard fought battle.

=== Example 2 ===
<hex>R10 C10 Q1 Va3 Vc6 Vb8 Vc8 Vd8 Ve8 Vg6 Vg7 Vg8 Hf5 Hf7 Hf8 He9 Hd9 Hc9 Hb9 Hd7</hex>

In this position, I was the vertical player and was expecting f6 to which h4 would give me an excellent position (with best play, this position would in fact be winning though this is not obvious). Instead my opponent played the excellent minimax move f4. This move fights in both directions and is in fact a killer move. I can't block the f4-f5 pair from the right due to the forking ladder escape at h9. Thus, I must meekly submit to the forcing sequence f6, e7, e6, d5 yielding

<hex>R10 C10 Q1 Va3 Vc6 Vb8 Vc8 Vd8 Ve8 Vg6 Vg7 Vg8 Hf5 Hf7 Hf8 He9 Hd9 Hc9 Hb9 Hd7 MH Mf4 Mf6 Me7 Me6 Md5</hex>

The game is over. The f4-f5 pair is connected to d5 which in turn threatens to connect to left in two non-overlapping ways, c5 (a 3rd row template) and d6, hence the pair is connected to the left. If I try to block at the right, the best I can do is yield a ladder (e.g. h4, h3, j2, i3 and H has a second row ladder) and then the forking ladder escape at h9 wins the game.

=== Example 3 ===
In the next example, I am the horizontal player and it is my move.

<hex>C10 R10 Q1 Va2 Vb5 Vb8 Vc7 Vd6 Vd5 Vf4 Hc6 Hc5 Hd4 He4 He5 Hf5</hex>

Most hex players would probably connect to the left side with a7 (or b6 or b7). Despite its apparent necessity, this move actually loses (against best play). Instead I played the winning minimax move d3! By adding a second non-overlapping connection threat to the left, my group of pieces maintains a connection to the left. And despite its modest appearance, d3 also helps out on the right and in fact guarantees a winning connection from f5 to the right by defeating one of the main potential blocking plays.

<hex>C10 R10 Q1 Va2 Vb5 Vb8 Vc7 Vd6 Vd5 Vf4 Hc6 Hc5 Hd4 He4 He5 Hf5 MH Md3</hex>

E.g. suppose V tries to block the f5 piece from the right as follows.

<hex>C10 R10 Q1 Va2 Vb5 Vb8 Vc7 Vd6 Vd5 Vf4 Hc6 Hc5 Hd4 He4 He5 Hf5 Hd3 M2g5 Mg4 Mi3 Mi2</hex>

4 at h4 would also be possible. Now I have a forced winning ladder down row 2, completing the win.

<hex>C10 R10 Q1 Va2 Vb5 Vb8 Vc7 Vd6 Vd5 Vf4 Hc6 Hc5 Hd4 He4 He5 Hf5 Hd3 Vg5 Hg4 Vi3 Hi2 Mh3 Mh2 Mg3 Mg2 Mf3 Mf2 Me3 Me2</hex>

This line clearly shows the usefullness of d3. If I hadn't played d3 (playing a7 instead, for instance), the vertical player could continue d3, d2, c3, c2, b3, b2, a3 and eventually winning with best play (considerable deep analysis is needed to show this).

<hex>C10 R10 Q1 Va2 Vb5 Vb8 Vc7 Vd6 Vd5 Vf4 Hc6 Hc5 Hd4 He4 He5 Hf5 Ha7 Vg5 Hg4 Vi3 Hi2 Vh3 Hh2 Vg3 Hg2 Vf3 Hf2 Ve3 He2 Md3 Md2 Mc3 Mc2 Mb3 Mb2 Ma3</hex>

Minimax moves are not always "parallel" moves. The principle of maintaining a minimal amount of connectivity in one direction while maximizing your strength in the opposite direction is more general than that.

=== Example 4 ===
The final example from a game of mine illustrates non-parallel mini-max moves. I was the vertical player and opened with 1. a3 and my opponent responded with 1... e4 yielding the following position.

<hex>C10 R10 Q1 V1a3 H2e4</hex>

I played the minimax move 2. f5 yielding

<hex>C10 R10 Q1 Va3 He4 V3f5</hex>

By connecting as far away as possible from the top, I increase my strength towards the bottom. (i.e. I am maintaining a minimal strength connection to the top while maximizing my strength towards the bottom). Before playing such a move, I have to verify that my opponent can't stop me from reaching the top. I could meet the attempted block with 2...g4 or 2...h2 by getting a third row ladder (2...g4 3.f4 g2 4.f3, etc. or 2...h2 3.g3 g2 4.f3, etc.), laddering down to e3, and then playing b4 (how to play a third row to a3 is described in a later section). I would be happy with such a line. My opponent however played the excellent e3. This move takes away the ladder, hence forcing me to reconnect to the top, while at the same time increasing his strength to the left.

<hex>C10 R10 Q1 Va3 He4 Vf5 H4e3</hex>

Here I played the minimax move g4. g4 has the potential to help block my opponent from going across the bottom of the board (e.g. Blue e7, Red f7, Blue f6, Red h5 and now g4 is helping out) or equivalently helps me to connect downwards on the right. I.e. g4 maintains a minimal strength connection towards the top while maximizing my strength towards the bottom. Note that a stronger move towards the top such as g3 does not have the same potential to help out towards the bottom. This potential may seem remote but in fact I would not have won the game without it! The rest of the game does not illustrate minimaxing but it is instructive nevertheless.

'''See [[Glenn_C._Rhoads_vs._unknown]]'''

== Special situations, tricks, etc. ==

=== Reconnecting edge template IIIa after an intrusion ===

<hex>R4 C10 Q1 Ve2 Hd3 Pf2 Se3</hex>

In this diagram, suppose you are Red and Blue has just played d3 intruding upon the third row template connecting your e2 to the bottom. Most hex players would reconnect with e3 without giving it much if any thought, yet there are three distinct ways to reconnect and there is often a reason for preferring one over the other.

A second way for Red to reconnect is to play f2 — the hex f2 and the empty hexes g2,e3,f3,g3,d4,e4,f4, and g4 form edge template IIIa; hence f2 has an unbreakable connection to the bottom and f2 is connected to e2.

The potential advantage of reconnecting with f2 over e3 is that it is easier to connect other pieces to the the group e2-f2 than to the group e2-e3 (e.g. h1 is a two-chain away from f2 but is not a two-chain away from either e2 nor e3). The extra connection possibilities can make a critical difference. For example, consider the following position with Red to move.

<hex>R9 C9 Q1 Vg2 Vf3 Ve4 Vd5 Vd6 Vh3 Vh4 Vf7 Hi4 Hc6 Hb8 Hc8 He6 Hf6 Hg6</hex>

Red can win by laddering 1. d7 d8 2. e7. Suppose instead Red plays 1.h5 intruding on the g6 edge template. If Blue reconnects with h6, then Red would have nothing else to do except play the winning line. So Blue reconnects with g7 making the win tougher. (Red could still win by d7, d8, e7, e9, f8, f9, h8! — a forking ladder escape which decides the issue).

Now suppose that Red again intrudes on the edge template with 2. h6. Now the game continues 2...g8 (again reconnecting by playing parallel to the edge) 3. h7 (persistent) h8, 4. d7 d8, 5. e7 e9! and now Blue has an unbreakable winning chain at the bottom. By reconnecting with the parallel moves instead of the direct reconnection, Blue's group had a new way to connect to the left and this extra possibility turned a defeat into a win.

So is it always better to reconnect with the parallel move? No!! Sometimes the parallel reconnection can lose the game while the simple direct connection wins! The potential weakness of the parallel reconnection is that your opponent might then be able to use a double threat to defeat the edge connection. For example, consider the following position with Red to move.

<hex>R9 C9 Q1 Vh3 Vg2 Vf3 Ve4 Vd5 Vd6 Hc6 Hb8 Hc8 He6 Hg5 Hi3</hex>

With best play Blue wins, so Red tries 1. h4. If Blue responds with the direct reconnection h5, then the win is assured and Red may as well resign. Suppose instead that Blue reconnects with 1... g6. Then Red can respond with 2.h7! — this forking ladder escape is a killer. Red now has two disjoint winning threats, laddering from d7 to h7 and play i5 (This double two-chain cutoff threat occurs in situations besides cutting off third row edge templates. It is well worth being familiar with this idea.). Blue cannot stop them both so Red wins.

But this doesn't exhaust the reconnection possibilities. There is a third way to reconnect; a way that most players don't seem to discover.

<hex>R4 C10 Q1 Ve2 Hd3</hex>

Again starting at the initial position in this section, Red's e2 piece is connected to the bottom via edge template IIIa and Blue intrudes upon it with d3. In addition to e3 and f2, Red can reconnect with the surprising f1!

<hex>R4 C10 Q1 Ve2 Hd3 Vf1</hex>

Red is threatening to connect e2-f1 to the bottom with e3. If Blue tries to block this with e3, then Red can reconnect by playing g2. g2 is connected to the bottom via template IIIa (Blue's e9 piece is just outside of this template) and h3 connects to f1 via a two-chain.

But what if Blue blocks with e4 instead of e3? (note the e4 is within the g2 piece's edge template). Then Red can still reconnect by playing as follows. 1. e3 d4 (forced) 2. g3 f3 (forced again) 3.g2 ending up with the following position.

<hex>R4 C10 Q1 Ve2 Hd3 Vf1 MH Me4 Me3 Md4 Mg3 Mf3 Mg2</hex>

How does this method compare to the previous two? Compared to the parallel reconnection, it is quite a bit more susceptible to forking plays and plays that encroach upon the increased area that is needed to reconnect, but by playing away from the edge, you have even more potential to connect the edge group towards the opposite edge. Sometimes the extra connection possibilities generated by playing away from the edge is exactly what is needed.

For example consider the beautiful solution to the following position which makes use of what I call "Tom's Move" (I wish I could take the credit for its discovery but the original over the board play was found by Tom239 on _Playsite_, he was at the orange level at the time!). The position below is a slight modification of one constructed by Kevin O'Gorman, the maintainer of the Ohex data base).

<hex>R10 C10 Q1 Va2 Va3 Va4 Va5 Va6 Va7 Va8 Va9 Ha10 Hb2 Hb3 Hb4 Hb5 Hb6 Hb7 Hb8 Vc6 Hc7 Vd5 Hd6 Vd7 Ve4 He5 Vf3 Hf4 Vg2 Hg3 Vh1 Hh2 Hi2</hex>

It is Red's move. To win, Red must connect his a9 piece to bottom. To do this, Red must make some ladder escape that additionally must somehow use the d7 piece to threaten another way to connect to the ladder. This looks impossible but yet there is a way. Red can win by starting with 1.b9 b10 2.c9 c10 3.f8!! (f8 is "Tom's Move").

<hex>R10 C10 Q1 Va2 Va3 Va4 Va5 Va6 Va7 Va8 Va9 Ha10 Hb2 Hb3 Hb4 Hb5 Hb6 Hb7 Hb8 Vc6 Hc7 Vd5 Hd6 Vd7 Ve4 He5 Vf3 Hf4 Vg2 Hg3 Vh1 Hh2 Hi2 Mb9 Mb10 Mc9 Mc10 Mf8</hex>

This brilliant move is the only way to win (it is, essentially, [[Tom's move]]). 3.g7 is defeated only by 3...d9 and 3.d9 d10 4.g7 is defeated only by 4...f8 (it takes a ''lot'' of analysis to demonstrate these claims). Blue's only good attempt is to intrude on the edge template with 3... e9. But Red can defeat this by reconnecting with 4.g7! (this is what Red had in mind when playing 3.f8!!)

<hex>R10 C10 Q1 Va2 Va3 Va4 Va5 Va6 Va7 Va8 Va9 Ha10 Hb2 Hb3 Hb4 Hb5 Hb6 Hb7 Hb8 Vc6 Hc7 Vd5 Hd6 Vd7 Ve4 He5 Vf3 Hf4 Vg2 Hg3 Vh1 Hh2 Hi2 Vb9 Hb10 Vc9 Hc10 Vf8 MH Me9 Mg7</hex>

Now f8-g7 has an unbreakable connection to the bottom and Red threatens two distinct ways of connecting this group back to the group containing c9; Red threatens f6, double two-chaining between d7 and g7, and Red threatens e8 two-chaining to c9. Blue's only possible defense is the forcing move 4...d8. This interferes with the immediate connection threat between c9 and f8, and it prepares to meet the f6 threat with c8 cutting off d7 from c9. But this move is still not sufficient because after 4...d8, Red can win with 5.d9 d10 (forced) 6.e8.

In practice, you can think of the parallel reconnection as your "standard" response (more often than not, it is the correct choice). But if the potential threat to cut off the parallel play from the edge is serious, then go with the direct reconnection. The "away" reconnection entails a substantially increased risk of being cut off from the edge but if you can see that it will be safe or if you need the stronger connection possibilities towards the opposite edge, then go with the "away" connection.

=== Third row ladder to a3 and its symmetric analogues ===
(See also the page [[a3 escape trick]])

The following position is from one of my games.

<hex>R10 C10 Q1 Hg2 Vi2 He3 Hg3 Hb4 Hc4 He4 Vf4 Vg4 Vb5 Vc5 Ve6 Vf6 Hh10</hex>

I am Blue and it is my move. Red's e6-f6(-f4-g4) group is connected to bottom via template Vb. Red's i2 piece is connected to the top via edge template II. In order to stop these two groups from connecting to each and completing a win, I must start laddering down column H. So I ladder down to h6 forcing Red to follow down column I to i6 yielding the following position.

<hex>R10 C10 Q1 Hg2 Vi2 He3 Hg3 Hb4 Hc4 He4 Vf4 Vg4 Vb5 Vc5 Ve6 Vf6 Hh10 Hh3 Vi3 Hh4 Vi4 Hh5 Vi5 Hh6 Vi6</hex>

My h10 piece is ''not'' a valid ladder escape. If I ladder all the way down to h10, then Red follows down to i8 and his response to h9 is not i9 but j9!

<hex>R10 C10 Q1 Hg2 Vi2 He3 Hg3 Hb4 Hc4 He4 Vf4 Vg4 Vb5 Vc5 Ve6 Vf6 Hh10 Hh3 Vi3 Hh4 Vi4 Hh5 Vi5 Hh6 Vi6 Hh7 Vi7 Hh8 Vi8 Hh9 Vj9</hex>

Red has a winning chain on the right side. You might think I could win by instead laddering down one more hex, and then double two-chain to the h10 piece yielding the following position.

<hex>R10 C10 Q1 Hg2 Vi2 He3 Hg3 Hb4 Hc4 He4 Vf4 Vg4 Vb5 Vc5 Ve6 Vf6 Hh10 Hh3 Vi3 Hh4 Vi4 Hh5 Vi5 Hh6 Vi6 Hh7 Vi7 Hg9</hex>

This may appear to settle the matter in my favor but in actuality, Red has a winning position! Red can win by 1. h8 (h9 also works but h8 is slightly more deceptive). If I respond by saving the link, i.e. by 1...g8, then Red wins by playing 2.h9 g10 (forced) 3. j9.

<hex>R10 C10 Q1 Hg2 Vi2 He3 Hg3 Hb4 Hc4 He4 Vf4 Vg4 Vb5 Vc5 Ve6 Vf6 Hh10 Hh3 Vi3 Hh4 Vi4 Hh5 Vi5 Hh6 Vi6 Hh7 Vi7 Hg9 Vh8 Hg8 Vh9 Hg10 Vj9</hex>

Red has an unbreakable winning chain down the right. Instead it is better for me to respond to Red's 1.h8 with 1...h9. My g9-h9-h10 group is now solidly connected to the right but Red can continue 2.g8 and I cannot stop g8 from connecting to the bottom because of the help provided by Red's e6-f6 pieces (work it out!)

In the initial position I cannot afford to ladder down any farther than g6. If I ladder down one more hex, I lose against best play no matter what. If there are no other pieces in the area, as is the case here, then the strongest way to play it is to ladder down one hex short of the hex that could double two-chain to the "almost-escape" piece, and then two chain up from the almost-escape piece which in our present case yields the following position.

<hex>R10 C10 Q1 Hg2 Vi2 He3 Hg3 Hb4 Hc4 He4 Vf4 Vg4 Vb5 Vc5 Ve6 Vf6 Hh10 Hh3 Vi3 Hh4 Vi4 Hh5 Vi5 Hh6 Vi6 Hg9</hex>

Red has three tries to stop the connection between the h6 and g9 pieces.

* g8 is defeated by continuing the ladder down (try it!).
* h7 and h8 are best met by f8 (double two-chaining in the same direction).
* Meeting the play h8 with g8 (connecting up to h6) doesn't work for the same reason that laddering down to h7 and double two-chaining to h10 doesn't work (work it out and you should see what I mean).

Also, note that Red's attempt h9 is of no consequence. Against h9 you should save the link with g10 and then again meet either h7 or h8 with f8.

In the actual game my opponent played h7 and I responded with f8. f8 threatens to connect with with h6 through g7. So my opponent played g7 to which I responded with f7. Again this threatens a winning connection from f7 to h6 through g6. So my opponent played g6 and I responded with c9 with a winning position.

<hex>R10 C10 Q1 Hg2 Vi2 He3 Hg3 Hb4 Hc4 He4 Vf4 Vg4 Vb5 Vc5 Ve6 Vf6 Hh10 Hh3 Vi3 Hh4 Vi4 Hh5 Vi5 Hh6 Vi6 Hg9 Vh7 Hf8 Vg7 Hf7 Vg6 Hc9</hex>

Further play no longer concerns the topic under discussion but the remaining moves were d9, e7, d7, d8, b9, c8, a8, b8, a9, b7, a7, d6, resigns. My opponent doesn't need to see g8, f9, h9, g10, j9, i8

The key play of two-chaining up from the escape piece is also useful in another common type of third row ladder position. For example, consider the following position with the vertical player to move.

<hex>R10 C10 Q1 He2 Vi2 Va3 Hf3 Hc4 Vd4 He4 Hf4 Vh4 Vi4 Vc5 Hd5 Hf5 Hh5 Vi5 Vc6 Hf6 Hg6 Hi6 Vc7 Hd7 He7 Vf7 Hg7 Vh7 Vc8 Vd8 Ve8 Hg8 Hh8 Hb9 Vc9</hex>

Red has a chain running from the bottom at c9 up to d4. The only way Red can win is to connect this group to the top. Red can ladder d3, c3, b3 but as we saw earlier, the a3 piece is not a valid ladder escape. But Red can still win by two-chaining from a3 to b4.

<hex>R10 C10 Q1 He2 Vi2 Va3 Hf3 Hc4 Vd4 He4 Hf4 Vh4 Vi4 Vc5 Hd5 Hf5 Hh5 Vi5 Vc6 Hf6 Hg6 Hi6 Vc7 Hd7 He7 Vf7 Hg7 Vh7 Vc8 Vd8 Ve8 Hg8 Hh8 Hb9 Vc9 Vb4</hex>

This threatens a winning connection to c5 through b5. If Blue blocks this with b5, then Red plays the ladder because now the pair a3-b4 are a valid ladder escape. If instead Blue blocks off the ladder with say c3, then Red wins with the line b5, b3, a4 (forced), b1, d2!

<hex>R10 C10 Q1 He2 Vi2 Va3 Hf3 Hc4 Vd4 He4 Hf4 Vh4 Vi4 Vc5 Hd5 Hf5 Hh5 Vi5 Vc6 Hf6 Hg6 Hi6 Vc7 Hd7 He7 Vf7 Hg7 Vh7 Vc8 Vd8 Ve8 Hg8 Hh8 Hb9 Vc9 Vb4 Hc3 Vb5 Hb3 Va4 Hb1 Vd2</hex>

d2 is a forking ladder escape; it threatens d3 and it provides an escape to the 2nd row ladder starting with b2. Blue cannot stop both winning threats with a single move, thus Red wins.

a3/j8 is a common opening move. If you frequently play it or play against somebody who does, then you will run into these 3rd row ladder situations and hence, it will be beneficial to learn how to play them.

=== The parallel ladder escape ===
(See also the page [[Parallel ladder]])

Consider the following position with Red to play.

<hex>R10 C10 Q1 Hc1 Vd2 Vd3 He3 Vf3 Vd4 Ve4 Hf4 Hg4 Ve5 Vc6 Vd6 He6 Hi6 Hc7 Vd7 Ha8 Hb8 Vc8 Hd8 Hb10</hex>

All of Red's pieces form a connected group. This group is connected to the top. At the bottom, Red has a second row ladder with no possible escape on the left. The potential escapes on the right are inadequate. For example, suppose Red ladders to f9. Then tries to escape with 5.h9 g9 6.h8 g8 7.h7 f7.

<hex>R10 C10 Q1 Hc1 Vd2 Vd3 He3 Vf3 Vd4 Ve4 Hf4 Hg4 Ve5 Vc6 Vd6 He6 Hi6 Hc7 Vd7 Ha8 Hb8 Vc8 Hd8 Hb10 Vc9 Hc10 Vd9 Hd10 Ve9 He10 Vf9 Hf10 Vh9 Hg9 Vh8 Hg8 Vh7 Hf7</hex>

Now Red's only reasonable try is 8.g7 f8. Now 9.g6 loses to 9...f5 and 9.h5 loses to the forcing sequence 9...g6 10.h6 h4 11.g5 f5. All the other escape attempts likewise fail. Is Red done for?

No! Red can create a sufficient escape by making use of a parallel ladder. In the original position Red plays 1.e7. How can Blue stop Red from connecting to the bottom? d9 lets Red two-chain from e7 to f8 connecting to the bottom; e9 and e10 allow d9 which is connected to the bottom and threatens to connect to Red's big group through c9 and e8; d10 loses to e8, f9 (forced), c10; hence, Blue is forced to play the parallel ladder move 1...e8. It is simplest for Red to repeat this and ladder to f7 forcing the 2...f8 response.

<hex>R10 C10 Q1 Hc1 Vd2 Vd3 He3 Vf3 Vd4 Ve4 Hf4 Hg4 Ve5 Vc6 Vd6 He6 Hi6 Hc7 Vd7 Ha8 Hb8 Vc8 Hd8 Hb10 Ve7 He8 Vf7 Hf8</hex>

Now Red now goes back to the second row ladder and tries to escape. What have we gained by preceding this with the parallel ladder moves? When trying to escape, the threat to connect to d7-e7-f7 is stronger than the previous weak threat to connect to d7. This extra threat will let us push our escape chain farther up the board and in this case, just far enough to win the game.

Red's winning sequence is long but rather simple because every one of Blue's replies is forced. As before, Red ladders to f9 and escapes with 7. h9. Play continues 7...g9 8.h8 g8 9.h7 g7 10.h6 g6 11.h5. Red is threatening to play g5 with the double winning threats f5 and f6. But if Blue blocks this, say with 11...g5, then Red continues 12.i3 i2 13.h3 and 14.g3 completes the win.

I have managed to pull this trick off from one row farther back; i.e. with ladders on row 3 and 5 but this occurs far less frequently and you have to examine some additional defensive possibilities. Consider the following position.

<hex>R10 C10 Q1 Vd5 He5 Vd6 Ve6 Hb7 Vc7 Hd7 Hb9</hex>

Red has just played e6 trying the parallel ladder exccape. With the closer ladder on row 2, we saw that Blue was forced to respond with the parallel ladder play e7. But here Blue has two additional possibilities e8 and c9 (the only other possibility where Red doesn't have a way to force his group to connect to the bottom is c10. But Red can respond with f8 and now Blue has nothing better than e7, g6).

e8 yields a second row ladder after d8, e7, c8, c10, d9. The play c9 also leads to a second row ladder after the likely f7, f8, e8 (d9 is met by e7) d10. In the latter case, Red could again try the parallel ladder escape by playing g7. Of course, the existence of other pieces in the area can change the possibilities.

For whom who understand The parallel ladder escape !
This trick is useful only for ladder 2nd and 4th!

Consider the following position with Red to play and win. Red's has winning position even with a blue stones in h5 from the beginning.
<hex>R10 C10 Q1
Hc1
Vd2
Vd3 He3 Vf3
Vd4 Ve4 Hf4 Hg4
Ve5 Hh5
Vc6 Vd6 He6 Hi6
Hc7 Vd7
Ha8 Hb8 Vc8 Hd8

Hb10 </hex>

[[parallel ladder#A parallel ladder escape puzzle|The solution is 1.f8]]

Note from original author (Glenn C. Rhoads):
I realized that my example had this improved solution which ruins the example but I never got around to writing a correct example. The move 1.f8 is essentially what I call "Tom's Move" in the last example of the section "Reconnecting template IIIa after an intrusion." The parallel ladder escape is when you can push the escape up by using the threats to connect to each branch of the parallel ladder. You might think Tom's move does away with the need for the parallel ladder escape but this is not the case. If you take the above position and shift every piece one hex to the right, then Tom's move no longer works because after blue's intrusion, there is not enough room to reconnect this piece to the bottom by playing the "away" connection (see Blue's third option in the provided solution). Yet there is still enough room to potentially ladder escape up the third row from the right edge. The example has to be modified to make the parallel ladder escape work and be the only way to win. Also, there are cases where the ladder starts at the far left and you must push the parallel ladders to the right in order to avoid some centrally located pieces. After pushing past them, Tom's move can then work. Both ideas are useful but Tom's move seems to work more often than the parallel ladder escape.

Also, I did have one game where I managed to pull off a parallel ladder escape from rows 3 and 5! I wish I had saved the moves of the game. The position was much too complex for me to ever remember it.

As an aside, I recall the conventional wisdom that every chess book ever written has mistakes in it (not literally true but a chess book without an error is a rarity indeed; even most beginner chess books have mistakes in them). Perhaps a similar thing could be said about Hex. Both games are at times very difficult and complex where it is all too easy to make a mistake. Of course I had no such intention of providing supporting evidence by my mistaken example. There is another mistake in my advanced guide. In the fourth example in the mini-maxing section, my first mini-maxing play can be defeated! In the subsequent game, my opponent plays an excellent move which I believe would have given him a winning position had it been played in the opening (with this hint, can you find the move?). I didn't bother trying to come up with another example out of sheer laziness. I wanted an opening example where mini-maxing would upon a close examination of the subsequent game, make a more or less direct difference in the outcome of game. Most examples of mini-maxing in the opening help in a less direct extremely complex way. I was reluctant to spend the time to find a good example and to provide a detailed analysis of the subsequent game when it seemed unlikely that anybody would notice the problem!

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

[[category:Advanced Strategy]]

HexWiki:About

2012-09-22T19:57:58Z

Roland Illig (Admin): Removed irrelevant history

HexWiki is a community initiative aimed at creating a central knowledge-base on the game [[Hex]]. The idea came about during discussions in the [http://www.littlegolem.net/jsp/forum/topic2.jsp?forum=50&topic=48 Hex forum] on [[Little Golem]].

Help:Hex

2012-09-09T23:14:06Z

Roland Illig (Admin): /* Examples */ example by visualization

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.

<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].

Help:Hex

2012-09-09T23:12:58Z

Roland Illig (Admin): /* Examples */ example by visualization

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.

<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.

== 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].

Help:Hex

2012-09-09T23:04:04Z

Roland Illig (Admin): /* Examples */ example by visualization

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.

<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''.
* '''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 ===
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].

Help:Hex

2012-09-09T22:59:08Z

Roland Illig (Admin): /* Examples */ example by visualization

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.

<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>#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 ===
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].

Help:Hex

2012-09-09T22:56:34Z

Roland Illig (Admin): /* Border */ explained

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 ===
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].

Talk:Rules

2012-09-09T22:51:26Z

Roland Illig (Admin):

The description of playing the game is really confusing, especially since the image of the board doesn't have any colors on the edges.
--[[User:Almo|Almo]] 17:50, 31 August 2012 (CEST)
: Did you have a look at [[Help:Hex#Border]]? It has long been marked "work-in-progress", but some minutes ago I finished implementing the blue border to the left and right. --[[User:Roland Illig (Admin)|Roland Illig (Admin)]] 00:51, 10 September 2012 (CEST)

Help:Hex

2012-09-09T22:48:03Z

Roland Illig (Admin): Implemented the "border" feature.

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 ===
<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].

History of Hex

2012-03-10T14:37:30Z

Roland Illig (Admin): cleaned up a dead link

== Early History ==
The game was first invented by the Danish mathematician [[Piet Hein]]. The first article describing the game, which Piet Hein called Polygon, appeared in the Danish newspaper [http://en.wikipedia.org/wiki/Politiken Politiken] on 26 December [http://en.wikipedia.org/wiki/1942 1942] but the game was introduced to an association of math students at The University of Copenhagen called [[The Parenthesis]] during a lecture on conditions for good games.

In [http://en.wikipedia.org/wiki/1948 1948] the game was discovered independently by the mathematican [[John Nash]]. Nash's fellow players at first called the game Nash. According to [[Martin Gardner]], some of the [http://en.wikipedia.org/wiki/Princeton_University Princeton University] students also referred to the game as John, because it was often played on the hexagonal tiles of bathroom floors. However, this story is, according to [[Jack van Rijswijck]], unfortunately apocryphal. In [http://en.wikipedia.org/wiki/1952 1952] [[Parker Brothers]] marketed a version. They called their version "Hex" and the name stuck.

== Recent History ==
The first book devoted to Hex and only Hex is available since 2000. [[Hex Strategy Making the Right Connections]], by [[Cameron Browne]].

As of 2008, [[Poland]] dominates the game of Hex.

''Here we could add something about the development of the different online communities.''

== Hex and Go ==
Hex has many similarities to the game Go.
One similarity is that both have a wiki dedicated to them, and each wiki has a page pointing to the opposite wiki: [[Go]] and [http://senseis.xmp.net/?Hex Sensei's library: Hex].

[http://senseis.xmp.net/?OtherGamesConsideredUnprogrammable Sensei's library: other games considered unprogrammable] lists other games similar to Go and Hex.

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

[[Tournaments]]

==References==
* Browne, Cameron (2000). Hex Strategy Making the Right Connection. A K Peters, Ltd. ISBN 1-56881-117-9.

[[category:history]]

History of Hex

2012-03-10T13:13:52Z

Roland Illig (Admin): external link has nothing to do with Hex.

== Early History ==
The game was first invented by the Danish mathematician [[Piet Hein]]. The first article describing the game, which Piet Hein called Polygon, appeared in the Danish newspaper [http://en.wikipedia.org/wiki/Politiken Politiken] on 26 December [http://en.wikipedia.org/wiki/1942 1942] but the game was introduced to an association of math students at [http://mydatapages.com/university_of_copenhagen.html The University of Copenhagen] called [[The Parenthesis]] during a lecture on conditions for good games.

In [http://en.wikipedia.org/wiki/1948 1948] the game was discovered independently by the mathematican [[John Nash]]. Nash's fellow players at first called the game Nash. According to [[Martin Gardner]], some of the [http://en.wikipedia.org/wiki/Princeton_University Princeton University] students also referred to the game as John, because it was often played on the hexagonal tiles of bathroom floors. However, this story is, according to [[Jack van Rijswijck]], unfortunately apocryphal. In [http://en.wikipedia.org/wiki/1952 1952] [[Parker Brothers]] marketed a version. They called their version "Hex" and the name stuck.

== Recent History ==
The first book devoted to Hex and only Hex is available since 2000. [[Hex Strategy Making the Right Connections]], by [[Cameron Browne]].

As of 2008, [[Poland]] dominates the game of Hex.

''Here we could add something about the development of the different online communities.''

== Hex and Go ==
Hex has many similarities to the game Go.
One similarity is that both have a wiki dedicated to them, and each wiki has a page pointing to the opposite wiki: [[Go]] and [http://senseis.xmp.net/?Hex Sensei's library: Hex].

[http://senseis.xmp.net/?OtherGamesConsideredUnprogrammable Sensei's library: other games considered unprogrammable] lists other games similar to Go and Hex.

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

[[Tournaments]]

==References==
* Browne, Cameron (2000). Hex Strategy Making the Right Connection. A K Peters, Ltd. ISBN 1-56881-117-9.

[[category:history]]

Six

2012-02-20T20:38:18Z

Roland Illig (Admin): Reverted edits by Sanders Dowdy (Talk); changed back to last version by Littlefish

Six is a free [[Hex]] playing program running on Unix written by Gábor Melis. The currently offered version is 0.5.3. It has won [[ICGA]] Hex tournament in 2003, 2004 and 2006. Six is quite good against human beings too.

==Features==

*It allows playing form [[board size|size]] 4 to 15.
*It offers 4 different skill levels (Beginner, Intermediate, Advanced, Expert).
*Games as well as positions can be saved.

==Windows Port==
Six has been adapted to Windows by [http://www.littlegolem.net/jsp/info/player.jsp?plid=6603 ab]. The project came out [http://www.littlegolem.net/jsp/forum/topic2.jsp?forum=50&topic=301 a thread] in the [[Little Golem]] forum. "ab" separated the GUI from the Six engine, thus creating [[HexGui]], inspired by GoGui.

To play the AI:
*Put HexGui.jar and six_gtp_engine.exe in one directory
*Double-click on HexGui.jar (or use "java -jar HexGui.jar")
*File menu / attach / "six_gtp_engine.exe --level=0"
*F5 to make a computer move, or
*Game menu / Computer plays / "Black" or "White" or "Both"

While the computer makes a move, which can take a while at expert level, you cannot access all the program functions.
The two zip files full of source code are unnecessary to play.

==See also==

[[Hexy]] is another Hex playing program. Hexy runs on Microsoft Windows.

[[Roland Illig vs. Six 0.5.3, 2007-09-28]].

==External links==

[http://six.retes.hu/ Six on Gábor Melis page].

[http://mgame99.mg.funpic.de/havannah.php Download Windows version].

[http://www.grappa.univ-lille3.fr/icga/round.php?tournament=100&round=1 8 games between Six and Mongoose] in the 8th Computer Olympiad in Graz (2003).

==References==

[http://www.littlegolem.net/jsp/forum/topic2.jsp?forum=50&topic=294 Six is pretty damn strong on a fast machine] a forum topic by David J Bush (top hex rating > 2150 on [[Little Golem]]).

[[category:Computer Hex]]
[[category:Hex playing program]]

Draw

2012-02-20T20:37:52Z

Roland Illig (Admin):

One of the beautiful properties of Hex is that the game can never end in a '''draw''', i.e., there is always a winner.

There are various ways of proving this, for example:

* A [http://www.cs.ualberta.ca/~javhar/hex/hex-galeproof.html proof] by [[David Gale]] that used the fact that exactly three hexes meet at every vertex.
* An [http://www.cs.ualberta.ca/~javhar/hex/hex-yproof.html elegant proof] using the [[Y|game of Y]].
* Another [[Y#No draws|proof]] using the game of Y.

In fact, David Gale showed that the no-draw property is equivalent to the 2-dimensional case of [http://en.wikipedia.org/wiki/Brouwer_fixed_point_theorem Brouwer's fixed point theorem] (a non-trivial theorem from topology saying that any continuous map from the unit square into itself must have a fixed point).

In 2006, [[Yasuhito Tanaka]] proved another equivalence involving Hex. The no-draw property is equivalent to the [[Arrow impossibility theorem]].

[[category:Theory]]

Draw

2012-02-20T20:37:08Z

Roland Illig (Admin): Reverted edits by Sanders Dowdy (Talk); changed back to last version by Adams Quinn

Draw

2011-12-18T00:52:00Z

Roland Illig (Admin): Reverted edits by VictoriaGreenham (Talk); changed back to last version by Halladba

Template:Http

2007-11-09T09:23:03Z

Roland Illig (Admin): removed

<noinclude>removed</noinclude>

Template talk:Http

2007-11-09T09:22:35Z

Roland Illig (Admin): removed

HexWiki:Community Portal

2007-11-09T09:21:55Z

Roland Illig (Admin): http

Does anyone know how to contact the sysop for this wiki? I and a few others are interested in contributing new content with hex diagrams, and note that the markup that used to work no longer does. Perhaps we can fix that.

-- kogorman

:Yes, here I am. Mail (through hexwiki@yahoogroups.com) is a good way, just as you did. I've replied to you now. Sorry for the delay. — [[User:Turing|turing]] 12:38, 14 Jul 2007 (CEST)

Question: Where is the Hex plugin for this wiki documented? Is it possible to mark moves with numbers like this:? <nowiki><hex>R11 C11 Va4[1] Ha5:2</hex></nowiki> I want to be able to draw diagrams like these: [http://senseis.xmp.net/?MonkeyJump]. --[[User:Roland Illig|Roland Illig]] 16:17, 13 Jun 2007 (CEST)

:Not possible in current plugin, sadly. Many of us would like it to, I think. Expertise is needed in how to improve the plugin, which right now is in a sad state. See recent mail on hexwiki@yahoogroups.com — [[User:Turing|turing]] 13:42, 14 Jul 2007 (CEST)

:: The hexwiki plugin is fully documented now. See [[Help:Hex]]. --[[User:Roland Illig|Roland Illig]] 20:05, 6 October 2007 (CEST)

User talk:Roland Illig

2007-11-09T09:21:27Z

Roland Illig (Admin): http

hello. Why do you change the links to <nowiki>{{http}}</nowiki> ?
: Because most spammers try to add pages to this wiki that contain external links, and they always have the text http:// in them. To prevent that, I am blocking every edit that contains this "bad word". Sure, there are better ways to do this, but this server is still stuck to PHP4, and recent MediaWiki versions (with good anti-spam extensions) require PHP5. --[[User:Roland Illig (Admin)|Roland Illig (Admin)]] 17:12, 8 November 2007 (CET)
:: From now on, external links can be written as usual. --[[User:Roland Illig (Admin)|Roland Illig (Admin)]] 10:21, 9 November 2007 (CET)

Help:Hex

2007-11-09T09:20:26Z

Roland Illig (Admin): http

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 =

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.

== 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''').

= 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>

== 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].

Ladder puzzle 2

2007-11-09T09:18:49Z

Roland Illig (Admin): http

Red to move and win.
From [http://www.littlegolem.net/jsp/game/game.jsp?gid=137809&nmove=30 game #137809] at [[Little Golem]], after move 30. k3.

:Theme: distant [[Ladder escape]].

<hex>R13 C13 Q1 Vb11 Vc10 Vd9 Vf8 Vg8 Vh9 Vi5 Vj6 Vj8 Vj9 Vk9 Vl4 Vl5 Vl6 Vm11 Hb12 Hc11 Hd4 Hd10 Hf10 Hf11 Hh10 Hi7 Hi8 Hi9 Hj7 Hk3 Hk5 Hk6</hex>

[[Ladder puzzle 2/Solution|Solution]]

[[Category: ladder puzzle]]

Proverbs

2007-11-09T09:18:10Z

Roland Illig (Admin): http

In [[Go]], there are many proverbs about strategy. Since the strategic concepts are very related, one might check whether the proverbs also apply to [[Hex]].

= External links =
* http://senseis.xmp.net/?GoProverbs

Move

2007-11-09T09:17:55Z

Roland Illig (Admin): http

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

Commented TwixtPP games

2007-11-09T09:17:42Z

Roland Illig (Admin): http

*[[Games from the 13th Little Golem TwixtPP Championship]]
*[[Games from the 14th Little Golem TwixtPP Championship]]

= External links =

* http://twixt.servegame.org/

Physical Hex sets

2007-11-09T09:17:30Z

Roland Illig (Admin): http

A (physical) Hex set was marketed under that name by Parker Bros. starting in 1952. Today, hand-made Hex sets can be bought at [http://www.mattesmedjan.se/produkter/index.html Mattesmedjan] in Sweden.

Here are some ideas on building a set:
* the page [http://www.nada.kth.se/~rydh/Hex/hexPics.html Hex Boards] has photos of wooden boards as used in the International Tournament 2005 in Wroclaw, Poland;
* Miguel Garcia has build a nice [http://members.fortunecity.es/zeycus/hexboard/hexboard.html set using steel nuts and ball-bearings];
* or you can use an [http://gregconquest.com/hex.html erase board and magnets].
* Łukasz Rygało submited [http://www.boardgamegeek.com/image/167362 this board] to [http://www.boardgamegeek.com BoardGameGeek].
* In the city of Alicante we have made [http://www.flickr.com/photos/liopic/1688139952 this board] with steel nuts and color-glass balls. We are looking for red and blue glass balls, though.

Online playing

2007-11-09T09:16:14Z

Roland Illig (Admin): http

Hex can be played online either using a web-based format or via e-mail.

==Web-based games==
Web-based games can be played either in ''real-time'', where moves are made within minutes (or even seconds), or ''turn-based'', where a player has days for one move.

The most popular sites are
* [[kurnik]] for real-time play,
* [[boardspace]] for real-time play
* http://www.ludoteka.com/ for real-time play
* and [[Little Golem]] for turn-based play.
* less popular but also turn based is [http://www.gamerz.net/pbmserv Richard's server]. One can play completely by e-mail, but it also has a [http://www.gamerz.net/pbmserv/List.php?Hex graphical interface] now. Furthermore any sized board is supported.
* http://www.googlegamecenter.com/ for real-time play, with time settings, and ranking. (Note: Despite the name, that page is not affiliated with Google.)

==E-mail-based games==

Hex may also be played over e-mail, in a turn-based fashion. The board can be represented in ASCII using either the full or compact formats below. The full layout is rotated 90 degrees from the compact one. (A fixed-width font is required for either board to display correctly in an e-mail client.)

<pre>
Full layout:

O _ X
O _/ \_ X
O _/ \_/ \_ X
O _/ \_/ \_/ \_ X
O _/ \_/ \_/ \_/ \_ X
O _/ \_/ \_/ \_/ \_/ \_ X
O _/ \_/ \_/ \_/ \_/ \_/ \_ X
O _/ \_/ \_/ \_/ \_/ \_/ \_/ \_ X
_/ \_/ \_/O\_/ \_/ \_/ \_/ \_/ \_
/ \_/ \_/ \_/ \_/X\_/ \_/ \_/ \_/ \
\_/ \_/ \_/ \_/ \_/ \_/ \_/ \_/ \_/
X\_/ \_/ \_/O\_/O\_/X\_/ \_/ \_/O
X\_/ \_/ \_/ \_/ \_/ \_/ \_/O
X\_/ \_/ \_/X\_/ \_/ \_/O
X\_/ \_/ \_/ \_/ \_/O
X\_/ \_/ \_/ \_/O
X\_/ \_/ \_/O
X\_/ \_/O
X\_/O

Compact layout:
/.\
/. .\
/. . .\
X /. . . .\ O
/. . . . .\
/. . . O . .\
/. . O . . . .\
/. . . . . . . .\
. . X O X . . . .
\. . . . . . . ./
\. . X . . . ./
\. . . . . ./
\. . . . ./
O \. . . ./ X
\. . ./
\. ./
\./
</pre>

Connection game

2007-11-09T09:15:40Z

Roland Illig (Admin): http

A '''connection game''' is a [[game]] where the goal is to use the [[Piece (general)|piece]]s to create a connection between some parts of the [[Board (general)|board]]. The first connection game was [[Hex]], which was invented in 1942, after which several other connection games have been created.

== Timeline ==

;[[Hex]] ([[Piet Hein]] 1942 and [[John Nash]] 1948)
:The original connection game. Played on a [[rhombic hex grid]].
;[[Y]] ([[Craige Schenstead]] and [[Charles Titus]], 1950s)
:Played on a [[triangluar grid of hexagons]]
;[[Twixt]] ([[Alex Randolph]], 1960s)
:Played on a [[square grid]] of holes into which the players place [[peg]]s. The pegs can be connected via [[Bridge (general)|bridges]].
;[[Havannah]] ([[Christian Freeling]], 1980)
;[http://www.di.fc.ul.pt/~jpn/gv/quax.htm Quax] (Bill Taylor?, 2000?)
:Played on a square grid with the possibility of diagonal connections.
;[[Onyx]] ([[Larry Back]], 2000)
:Played on an original grid consisting of both triangles and squares. It is the first connection game with a [[capturing rule]].
;[[Gonnect]] ([[João Pedro Neto]], 2000)
:This game is simply [[Go]], but with a different goal, namely to create a connection between any two opposite sides.
;[[Unlur]] ([[Jorge Gómez Arrausi]], 2001)
:Played on a [[hexagonal hex grid]]. Unique in the way that the players have [[different objectives]].
;[[Connecto]] (unknown author, unknown year)
:Played on an interlaced square board.

== References ==

;[[Cameron Browne]], [http://www.amazon.com/Connection-Games-Variations-Cameron-Browne/dp/1568812248/ref=pd_bbs_sr_1/104-1532904-9846317?ie=UTF8&s=books&qid=1177663469&sr=8-1 "Connection Games: Variations on a Theme"]

Puzzle server

2007-11-09T09:14:44Z

Roland Illig (Admin): http

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 intependent -> Java)
* Database for recording the problems

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

Help:Contents

2007-11-09T09:13:41Z

Roland Illig (Admin): changed anti-spam measures

[[HexWiki]] is a [[Wikipedia:Wiki|wiki]] for the game of [[Hex]], i.e., it is a website written collaboratively by people from around the world.

The [[Wikipedia:Help:Contents|help page for Wikipedia]] contains guidance and information about participating which is mostly applicable to HexWiki as well (since both the Wikipedia and HexWiki are based on the MediaWiki software).

The plug-in for drawing Hex diagrams is documented on its own page: [[Help:Hex]].

User talk:Gregorio

2007-11-09T09:12:41Z

Roland Illig (Admin): Update to external links

== External links ==

Hello Gregorio,

it is quite easy to embed external links. See [[Help:Contents]], the last paragraph. --[[User:Roland Illig|Roland Illig]] 20:20, 4 November 2007 (CET)

: Thanks!!!!! --[[User:Gregorio|Gregorio]] 13:23, 5 November 2007 (CET)

:: Update: You can now write external links as http://, since I changed the spam protection. --[[User:Roland Illig (Admin)|Roland Illig (Admin)]] 10:12, 9 November 2007 (CET)

== Hi ==

Hi! (Buenas!)

--[[User:RBerenguel|RBerenguel]] 22:46, 8 November 2007 (CET)

Talk:Y

2007-11-08T16:13:44Z

Roland Illig (Admin): answer

As a project for university I made with my team a proof of y having no draws. I wrote it in wikipedia, am I allowed to copy it here ?
: If you are the author of the text, sure. This is mainly a wiki about Hex, but looking a bit around shouldn't jhurt anyone. ;) --[[User:Roland Illig (Admin)|Roland Illig (Admin)]] 17:13, 8 November 2007 (CET)

User talk:Roland Illig

2007-11-08T16:12:21Z

Roland Illig (Admin): answer

hello. Why do you change the links to {{http}} ?
: Because most spammers try to add pages to this wiki that contain external links, and they always have the text {{http}} in them. To prevent that, I am blocking every edit that contains this "bad word". Sure, there are better ways to do this, but this server is still stuck to PHP4, and recent MediaWiki versions (with good anti-spam extensions) require PHP5. --[[User:Roland Illig (Admin)|Roland Illig (Admin)]] 17:12, 8 November 2007 (CET)

MediaWiki:Sidebar

2007-10-28T08:39:14Z

Roland Illig (Admin): Removed unneeded entries

Wroclaw game 08

2007-10-10T15:48:36Z

Roland Illig (Admin): move numbers

'''Red player:''' na_wspak<br>
'''Blue player:''' David Rydh<br>
'''Date:''' 2005-05-07

<hex>
R13 C13 Q1 N:on Vm7 Hg7 Ve7 He8 Vc9 Hd9
</hex>

<hex>
R13 C13 Q1 Vm7 Hg7 Ve7 He8 Vc9 Hd9 N:on Vf7 Hf9 Vc10 Hc7 Vf8 He9 Vd7 Hc11
</hex>

<hex>
R13 C13 Q1 Vm7 Hg7 Ve7 He8 Vc9 Hd9 Vf7 Hf9 Vc10 Hc7 Vf8 He9 Vd7 Hc11 N:on Vd10 Hc10 Ve10 He11 Vg10 Hh10
</hex>

<hex>
R13 C13 Q1 Vm7 Hg7 Ve7 He8 Vc9 Hd9 Vf7 Hf9 Vc10 Hc7 Vf8 He9 Vd7 Hc11 Vd10 Hc10 Ve10 He11 Vg10 Hh10 N:on Vg11 Hf10 Vh8 Hg8 Vi6 Hi5 Vh6 Hh4 Vg6 Hg3
</hex>

<hex>
R13 C13 Q1 Vm7 Hg7 Ve7 He8 Vc9 Hd9 Vf7 Hf9 Vc10 Hc7 Vf8 He9 Vd7 Hc11 Vd10 Hc10 Ve10 He11 Vg10 Hh10 Vg11 Hf10 Vh8 Hg8 Vi6 Hi5 Vh6 Hh4 Vg6 Hg3 N:on Vd4 He5 Vc5 Hd5 Vg4 Hh2 Vf4
</hex>

Blue resigns.

[[Category:Wroclaw_games]]

Commented TwixtPP games

2007-09-25T21:26:15Z

Roland Illig (Admin): typo

*[[Games from the 13th Little Golem TwixtPP Championship]]
*[[Games from the 14th Little Golem TwixtPP Championship]]

= External links =

* {{http|//twixt.servegame.org/}}

Help:Hex

2007-09-20T20:08:15Z

Roland Illig (Admin): /* Examples */ typo

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

Each diagram consists of the board settings and the pieces that are placed on the board. All this is enclosed in <tt><hex></tt>...<tt></hex></tt> tags.

= Syntax =

The description of a Hex diagram consists of a series of words. 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 =

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.

== 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''').

= 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.

Currently, the number of moves is restricted to 10, but this may be extended if there is the need for it.

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.

== 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''.

= 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>

== Numbered moves ==

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

Help:Hex

2007-09-20T20:07:53Z

Roland Illig (Admin): /* Automatically numbered moves */ explained how to start with a blue move; provided some examples

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

Each diagram consists of the board settings and the pieces that are placed on the board. All this is enclosed in <tt><hex></tt>...<tt></hex></tt> tags.

= Syntax =

The description of a Hex diagram consists of a series of words. 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 =

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.

== 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''').

= 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.

Currently, the number of moves is restricted to 10, but this may be extended if there is the need for it.

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.

== 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''.

= 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>

== Numbered moves ==

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

Talk:Advanced (strategy guide)

2007-09-20T19:57:38Z

Roland Illig (Admin): Reverted edits by ArxIfs (Talk); changed back to last version by Roland Illig

= Template Va =

: Does the hex at a1 really have to be empty? --[[User:Roland Illig|Roland Illig]] 14:02, 15 Jun 2007 (CEST)
::Not sure I understand your question, Roland. It says in the next paragraph that hexes marked '*' are not relevant to the template, i.e. it doesn't matter whether a1 is empty or not. I think I will move this discussion shortly to the Talk page, so that it doesn't disturb the flow of the tutorial. — [[User:Turing|turing]] 13:53, 14 Jul 2007 (CEST)
::: Oops, I meant either J1 or A6, though I don't remember which one I meant. :( --[[User:Roland Illig|Roland Illig]] 23:52, 8 Sep 2007 (CEST)

Basic (strategy guide)

2007-09-20T19:55:44Z

Roland Illig (Admin): Reverted edits by JvbWtl (Talk); changed back to last version by 213.39.183.228

''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 [[Hex (board element)|hexagon]]. The [[first player]]'s goal is to form an unbroken [[chain]] of hexes of his color that [[connection|connects]] the [[top edge|top]] to the [[bottom edge|bottom]] while the [[second player]] tries to form an unbroken chain connecting the [[left edge|left]] and [[right edge|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 [[pattern|formation]] consisting of two pieces that are [[non-adjacent]] but have two empty [[adjacent|neighboring]] hexes in common is referred to as a [[bridge|two-bridge]]; e.g. the pieces on b2 and c3, and the [[empty hex]]es 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 at a distance. If you block too close, then the opponent 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 Q1 Vh1 Vh2 Vh3 Vg4 Vg5 Vg6</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 Q1 Vh1 Vh2 Vh3 Vg4 Vg5 Vg6 MH Mg7 Mf7 Me8 Mf8</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 Q1 Vh1 Vh2 Vh3 Vg4 Vg5 Vg6 MH Mf8 Mh7</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 Q1 Vh1 Vh2 Vh3 Vg4 Vg5 Vg6 MH Mg7 Mf7 Me9</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 Q1 Vh1 Vh2 Vh3 Vg4 Vg5 Vg6 MH Mf9 Mf8 Me9 Mh7 Mh8 Me7 Md8</hex>

== 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 I will look for the connection that my opponent is going to have the toughest time making (point 3.1 above), e.g 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. This is very sound strategy.

=== 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 [[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.

=== 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 [[Wikipedia:Go_(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 100 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.