Jonathan Schaeffer (the guy behind this project) gave a speech at this year's SIGCSE (computer science education) conference. The article says that artificial intelligence techniques were used to solve checkers, but it was really just brute force. He had a database of all possible 10-piece setups solved, and then he began iterating over all other positions. Of course, once a position reduced to one of the 10-piece positions, that particular game was solved.<p>The guy actually seemed a bit nutty to me. The motivation for the whole endeavor was to demonstrate that his AI player (Chinook) was provably better than an amazing human checkers player by the name of Marion Tinsley. In a 45-year career, the man never lost a World Championship match, and he only ever lost 9 games (2 to Chinook). Do keep in mind that championship checkers matches are 39 games, meaning that he played thousands and thousands of games.<p>Anyways, a PDF of his talk is available here: <a href="http://www.cs.potsdam.edu/sigcse07/schaefferTalk.pdf" rel="nofollow">http://www.cs.potsdam.edu/sigcse07/schaefferTalk.pdf</a> . It was an interesting story, even if I thought the presenter was a bit strange.