HexWiki - User contributions [en]

Swap

2012-09-10T01:32:50Z

Almo: Add goal color bars

==The rule==
After [[Red]] played the first move [[Blue]] player is asked wether she wants to swap or not, that is to invert the colors or to keep on this way.
[[Swap_rule|Detailled article]].

==Where to swap==
The use of the swap rule is to force the first player to play not too good moves. Therefore it is intersting to find out what are the moves that should be swapped (the best moves), what are moves that should not be swapped (the worse moves), what are the moves for which no answer is known yet.

On every size [[a1_opening|a1]], b1 and symmetrical moves are known losing moves (except 2 x 2, where b1 wins, see [[small boards]]).

*The red marked hexes are to be swapped.

*The blue marked hexes are not to be swapped.

*The star marked hexes are average moves, so the game should be balanced with or without swap.

Hex is not strongly solved on big sizes, therefor the result of [[optimal play]] is not known for every cells.

=== Small Sizes ===

See [[Small boards]] to know which cells lead to victory with optimal play. You might however assume that you and your opponent do not play optimally, and decide to play tricky losing moves in order to trap your opponent !

=== Bigger Sizes ===

[[Theory|Theoritical]] outcome is known for a few cells (for instance a1). For the other cells, stronger players advice can give a hint on whether a move should be swapped or not. One could also try to recognize a pattern in the winning cells for small boards and extrapolate to bigger sizes.

====Size 10====
<hex>R10 C10 Ha1 Hb1 Hc1 Hd1 He1 Hf1 Hg1 Hh1 Hi1 Vj1
Sa2 Sb2 Sc2 Vd2 Ve2 Vf2 Vg2 Vh2 Vi2 Vj2
Sa3 Vb3 Vc3 Vd3 Ve3 Vf3 Vg3 Vh3 Vi3 Vj3
Va4 Vb4 Vc4 Vd4 Ve4 Vf4 Vg4 Vh4 Vi4 Vj4
Va5 Vb5 Vc5 Vd5 Ve5 Vf5 Vg5 Vh5 Vi5 Vj5
Va6 Vb6 Vc6 Vd6 Ve6 Vf6 Vg6 Vh6 Vi6 Vj6
Va7 Vb7 Vc7 Vd7 Ve7 Vf7 Vg7 Vh7 Vi7 Vj7
Va8 Vb8 Vc8 Vd8 Ve8 Vf8 Vg8 Vh8 Vi8 Sj8
Va9 Vb9 Vc9 Vd9 Ve9 Vf9 Vg9 Sh9 Si9 Sj9
Va10 Hb10 Hc10 Hd10 He10 Hf10 Hg10 Hh10 Hi10 Hj10 B:on</hex>

==== Size 14 ====
TODO
==== Size 19 ====
TODO
==See also==

[[Basic (strategy guide)#10_.C3.97_10_swap_rules|Guideline for the 10x10]], in the basic strategy guide.

==External links==

[http://www.cs.cmu.edu/People/hde/hex/hexfaq/ A faq about Hex]

[http://www.cs.ualberta.ca/~queenbee/openings.html A more complete site] with solution to sizes 7. Beware, the colors are inverted, vertical is blue there.

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

Rules

2012-09-10T01:32:10Z

Almo:

== 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.

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

== 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.

Talk:Rules

2012-08-31T15:50:04Z

Almo:

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)

Talk:Swap

2012-08-31T15:46:19Z

Almo:

What is the source for these positions? For board sizes <= 6x6 the queenbee page has proved theorems by brute force. For 7x7 what is the source? and for 10x10 is the wiki asserting that the moves with colours are provable wins for those colours? It's not clear to me whether these assertions are rigorously proved, or just "what the experts think".

[[User:Wccanard|Wccanard]] 17:20, 31 December 2008 (CET)

http://www.ru.is/faculty/yngvi/pdf/HaywardBJKPR05.pdf is a reference for 7x7.

http://www.cs.ualberta.ca/~queenbee/openings.html is a reference for <= 6x6.

In my opinion these should be included in the article. I am still unclear about what precisely is being asserted for 10x10.

[[User:Wccanard|Wccanard]] 18:37, 31 December 2008 (CET)

I agree with Wcccanard that some references must be given. The article is obscure in a) references, b) what is really asserted. --[[User:Gregorio|Gregorio]] 19:56, 4 January 2009 (CET)

I don't understand the diagram, and which sides of the rhombus are blue or red.
--[[User:Almo|Almo]] 11:46, 31 Aug 2012 (CET)