Chinook becomes checkers champion

Marion Tinsley lost nine games of checkers in forty-five years and was probably the most dominant player of any game in history. In 1992 he beat Chinook, a program from the University of Alberta, four games to two with 33 draws. In August 1994 they met again in Boston; after six draws Tinsley withdrew, was found to have pancreatic cancer, and died the following spring. Chinook was declared world champion, the first machine to hold a title against humans in any game.

Jonathan Schaeffer's program was in the tradition of Shannon and Samuel: deep search with an evaluation function, plus a large opening book and, crucially, endgame databases that held the perfect play for every position with eight or fewer pieces. The databases were the innovation, and they grew until in 2007 they covered the whole game.

The Tinsley match is the first of the man-versus-machine moments that punctuate the next twenty-five years, Deep Blue in 1997, Watson in 2011, AlphaGo in 2016, and it set the pattern for their reception. The public read it as a machine out-thinking a person. Schaeffer knew it as a machine out-remembering one, and a human who was ill.