Difference between revisions of "Hex theory"

From HexWiki
Jump to: navigation, search
m (added cat. theory)
(reorganised: heading + inner links + external link + complexity + TODO)
Line 1: Line 1:
Unlike many other games, it is possible to say certain things about [[Hex]], with absolute certainty. While, for example, nobody seriously believes that black has a winning strategy in [http://en.wikipedia.org/wiki/Chess chess], nobody has been able to prove that such a strategy doesn't exist. In Hex, on the other hand, a simple argument can show that the [[Blue (player)|second player]] certainly does not have a winning strategy from the [[starting position]] (when the [[Swap rule|swap option]] is not used). Whether this makes Hex a better game is of course debatable, but many find this attribute charming.
+
Unlike many other games, it is possible to say certain things about '''[[Hex]]''', with absolute certainty. Whether this makes Hex a [[why did you start playing Hex|better game]] is of course debatable, but many find this attribute charming.
  
 
The most important properties of Hex are the following:
 
The most important properties of Hex are the following:
  
* The game can not end in a [[draw]]. ([http://javhar1.googlepages.com/hexcannotendinadraw Proofs] on Javhar's page)
+
== Winning Strategy ==
* The [[Red (player)|first player]] has a [[winning strategy]].
+
 
* When playing with the [[swap]] option, the second player has a winning strategy.
+
While nobody seriously believes that black has a winning strategy in [http://en.wikipedia.org/wiki/Chess chess], nobody has been able to prove that such a strategy doesn't exist. In Hex, on the other hand, a simple [[strategy-stealing argument|argument]] can show that the [[Blue (player)|second player]] certainly does not have a '''[[winning strategy]]''' from the [[starting position]]:
 +
 
 +
* When the [[Swap rule|swap option]] is not used, the [[Red (player)|first player]] has a winning strategy.
 +
* When playing with the swap option, the second player has a winning strategy.
 +
 
 +
== [[Complexity]] ==
 +
 
 +
* The decision problem associated to generalised Hex is '''PSPACE-complete'''.
 +
* The detection of [[dominated cell]]s is NP-complete. ('''To be checked''' then sourced)
 +
 
 +
== Solving Hex ==
 +
 
 +
* Hex has been solved on [[small boards]].
 +
* The game can not end in a [[draw]]. ([http://javhar1.googlepages.com/hexcannotendinadraw Proofs] on [[Jack van Rijswijck|Javhar]]'s page)
  
 
== See also ==
 
== See also ==
  
 
[[Open problems]]
 
[[Open problems]]
 +
 +
== External links ==
 +
 +
* [[Thomas Maarup]] masters [http://maarup.net/thomas/hex/ thesis]
  
 
[[category:Theory]]
 
[[category:Theory]]

Revision as of 21:33, 3 December 2008

Unlike many other games, it is possible to say certain things about Hex, with absolute certainty. Whether this makes Hex a better game is of course debatable, but many find this attribute charming.

The most important properties of Hex are the following:

Winning Strategy

While nobody seriously believes that black has a winning strategy in chess, nobody has been able to prove that such a strategy doesn't exist. In Hex, on the other hand, a simple argument can show that the second player certainly does not have a winning strategy from the starting position:

  • When the swap option is not used, the first player has a winning strategy.
  • When playing with the swap option, the second player has a winning strategy.

Complexity

  • The decision problem associated to generalised Hex is PSPACE-complete.
  • The detection of dominated cells is NP-complete. (To be checked then sourced)

Solving Hex

See also

Open problems

External links