Chinook: Computer Checkers Program

Chinook is a computer program on checkers most preferred by most checkers enthusiasts. Here is a summary of how the program started and developed.

It was in Jonathan Schaeffer who first came up with the idea of a checkers computer program in 1989. Today this is the most popular checkers program for computers. Schaeffer first started with a program for chess but later decided to do programs for checkers instead. So what he did first was to gather a team.

The team was composed of a checkers expert, Norman Treolar, the endgame databases was handled by Robert Lake, while Martin Bryant provided opening strategies for Chinook, the checkers program, and compiled them in a book. For the analysis of the function and the opening strategies Treolar was also in charge. Lots of graduate students also join in the band wagon.

Among the fine features that Chinook contributed to computerized checkers was the introduction of the so-called endgame databases. There had been a system for doing retrograde examinations of checkers games. It was done first by Strohlein. The system was tried out for chess by Ken Thompson.

Databases were made by the Schaeffer team which provided the checkers computer program excellent information for all possible formations or positions using 8 pieces or fewer on the board. This was used to calculate winning odds in the game, specifically how long till a win is effected. With this system less information is needed to give way for more important ones in the database. Access becomes easier too.

The Schaeffer team got to play with world title holder Marion Tinsley in 1992. But the team lost, gaining merely 2 wins in 6 games. However, we should note that during the match the team was not yet armed with the database involving 8 pieces yet. In a 1994 re-match the database was used which resulted in 6 draws. However, Tinsley's untimely death cut the story short and never produced a conclusion.

The Chinook program then started to defeat opponents like Don Lafferty, seen as second to Tinsley in skill and popularity. The Chinook program and team started to gain prominence in the checkers US scene, especially in 1996. After this, with no more challengers to take on, the Chinook program was discontinued. Later on, however, another versionóa 6-piece database systemówas introduced and became the official system used for PC programs for a long while.

The Chinook checkers computer program was the first and still among the best PC programs for checkers.