History
Marion Tinsley vs Chinook
The best checkers player who ever lived, a computer program built to beat him, and two matches that ended in a way nobody wanted.
Short answer
Marion Tinsley, world champion from 1955 to 1958 and again from 1975 to 1991, beat the program Chinook in London in 1992, by 4 wins to 2 with 33 draws. Their 1994 rematch in Boston stopped after six draws, when Tinsley withdrew because of illness, and Chinook took the title. He died the next year. In 2007, Chinook’s team proved that checkers is a draw.
The man who almost never lost
Marion Tinsley was an American mathematician, and the greatest checkers player there has ever been. He was world champion from 1955 to 1958, and again from 1975 to 1991. He never lost a world championship match, and between 1950 and 1991 he lost only three games.
That record is hard to believe in a game where one slip can cost you everything. But even Tinsley wasn’t perfect. Now and then, he made a losing mistake.
A program built to beat him
In 1989, Jonathan Schaeffer and his team at the University of Alberta began building Chinook, a checkers program with one aim: to beat the world champion. It improved quickly. In 1990, it earned the right to play for the world title by finishing second to Tinsley at the US national championship.
At first, the American and English checkers federations were against a computer playing in a human championship. Tinsley resigned his title in protest, and the federations created a new one for the match: the Man-Machine World Championship.
London, 1992
Tinsley and Chinook met in London in August 1992, over 39 games. Tinsley won the match by four wins to two, with 33 draws. It was close, and Chinook’s two wins were losses of a kind he almost never suffered.
Boston, 1994
By the 1994 rematch, at the Computer Museum in Boston, Chinook was much stronger, and it used part of a database of every position with eight pieces or fewer. The first six games were all draws. Then Tinsley withdrew, saying he wasn’t well, and Chinook was declared champion: the first program to win a world title against people.
Soon afterwards he was found to have pancreatic cancer. He died in April 1995, eight months after the match, aged 68. The question of who was better, Tinsley or the machine, was never settled over the board.
What happened next
By 1996, Chinook was much stronger than any person, and the gap kept growing as computers got faster. But being stronger than people isn’t the same as being perfect. To settle it for good, Schaeffer’s team set out to solve the game: to prove what happens if neither side ever makes a mistake.
It took until 2007. The answer was a draw. A program playing the proof can never lose, and that, in the end, is the only way a computer could be sure of being better than Tinsley. Read how checkers was solved.
- 1955 to 1958Tinsley is world champion for the first time.
- 1975 to 1991He’s world champion again.
- 1989The Chinook project begins at the University of Alberta.
- 1990Chinook comes second to Tinsley at the US championship, earning a shot at the world title.
- 1992London: Tinsley beats Chinook, 4 wins to 2 with 33 draws.
- 1994Boston: after six draws, Tinsley withdraws because of illness, and Chinook is declared Man-Machine World Champion.
- 1995Tinsley dies in April, aged 68.
- 2007Chinook’s team proves that checkers is a draw.
Why people still play
Computers have been better than us at checkers since the 1990s. People still play, for the same reason they play chess: a game against someone at your own level is as good as it ever was. That’s what Checky’s 40 bots are for, from Pip, who’s still learning, up to master level. Pick one and play.
Sources
- Jonathan Schaeffer and others, “Checkers Is Solved”, Science 317, 1518–1522 (2007). doi.org/10.1126/science.1144079
- Wikipedia, “Chinook (computer program)” and “Marion Tinsley”.
Questions people ask
Who was Marion Tinsley?
An American mathematician and the greatest checkers player ever. He was world champion from 1955 to 1958 and from 1975 to 1991, and lost only a handful of games in four decades.
Did Chinook beat Marion Tinsley?
Not in a finished match. Tinsley won their 1992 match 4 wins to 2, with 33 draws. Their 1994 rematch stopped after six draws, when Tinsley withdrew because of illness.
What was Chinook?
A checkers program built at the University of Alberta by Jonathan Schaeffer’s team, starting in 1989. The same team later used it to prove that checkers is a draw.
