In 1992, Marion Tinsley, who seemed unbeatable at checkers, defended his title against the computer program CHINOOK. After a tough, close match, Tinsley came from behind to win by getting four wins to CHINOOK's two wins and 33 draws. 

This incident was the first time in history that a human world champion defended his title against a computer.

Overview

The most well-known checker-playing program from 1955 to 1965 was Samuel's (1967, 1959). This research continues to mark a turning point in AI. 

However, pursuing a checker program that could compete in world championships received little attention, save for one from Duke University in the 1970s (Truscott 1979). To learn more about heuristic search using a less complex experimental domain than chess, the CHINOOK Project began in 1989. 

Moreover, Chinook is an algorithm that plays checkers (also known as draughts). It was created at the University of Alberta between 1989 and 2007 by a group directed by Jonathan Schaeffer and consisting of Rob Lake, Paul Lu, Martin Bryant, and Norman Treloar. 

Algorithm

The program's algorithms include:

• An opening book.
• A library of opening moves from checkers grandmasters' games.
• A deep search algorithm.
• A good move evaluation function.
• An end-game database for all positions with eight or fewer pieces.

Chinook is the first computer program to beat people at a game and win the world champion title. In 1990, it got to play in the human World Championship because it came in second at the US Nationals, behind Marion Tinsley. At first, the American Checkers Federation and the English Draughts Association didn't want a computer to participate in a tournament between humans. Tinsley gave up his title in protest, so the ACF and EDA came up with a new name for the competition: the Man vs Machine World Championship. Tinsley won because he had four wins to Chinook's two, with 33 ties.

Achievements

In a rematch against Marion Tinsley in 1994, Chinook was declared the Man-Machine World Checkers Champion after six draws and Tinsley's withdrawal due to pancreatic cancer. Even though Chinook won the world championship, it never beat Tinsley, the best checkers player. 

In 1995, Chinook played Don Lafferty in a 32-game match to defend its man-machine title. In the end, Chinook beat Lafferty with a score of 1-0 and 31 ties. After the match, Jonathan Schaeffer decided that Chinook shouldn't play anymore and that he should instead try to figure out how to win at checkers. At the time, it had an Elo score of 2814. researchers found the answer, and researchers wrote up the result in 2007.

CHINOOK uses the most up-to-date parallel alpha-beta search algorithm. In addition, the machine had four times as much RAM and twice as many processors as it did in 1992. Because of the better hardware, the program could search at least two layers deeper. 

Conclusion

The success of the CHINOOK team is due to Marion Tinsley. Tinsley may have declined the challenge posed by a machine with the support of the checker federations. Tinsley was solely interested in competing against the best players, whether they were human or artificial. Due to a lack of human competition, their initiative might have died in 1990. However, with Tinsley's assistance, CHINOOK was able to compete in the most prestigious checkers events and play against the world's best players.

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