American Mathematical Monthly , number 86, 1979. Acta Informatica , volume 15, pp. An Automatic Theorem Proving Approach to Game Programming. Will appear in AAAI-2000 proceedings. Hex is simple, but standard computer chess methods would be woefully inadequate.
Human players use several powerful reasoning techniques to analyse the game.
A good Hex program must approximate these methods. That's what my thesis work was about, but I never finished it. I am very impressed by Vadim Anshelevich's web page, especially the Download section where you can download his strong hex-playing program Hexy and also a very nice paper about its algorithms. Jack van Ryswyck's web page is also very interesting. He has a paper there about his Hex-playing program Queenbee.