How Computers Play Games - Robots Unlimited: Life in a Virtual Age - page 90

Figure 26. Marion Tinsley (right) in play versus Chinook (operated by Jonathan Scha-
effer), the World Checkers 21 (Draughts) Championship, London 1992 (Courtesy of

Jonathan Schaeffer)

In 1990 Chinook came second to the legendary Marion Tinsley at the
U.S. Open Checkers Championship, proving itself ready to challenge
Tinsley to a match for the World Checkers Championship (see Figure
26 ) . Winning a match against Tinsley was an intermediate goal on the
road to solving the game completely—Tinsley had lost only three games
in a span of 40 years. The match was played in London in 1992, with
Chinook having the benefit of an openings topic developed by Martin
Bryant, whose research had found some flaws in the established Checkers
openings literature.
Although Chinook took the lead in the match by winning the eleventh
game of the 40-game series, eventually Tinsley drew level, then went
ahead and remained ahead until the end. Schaeffer and his team had
come very close to dethroning Tinsley but, in the end, Tinsley's faith was
vindicated. In an interview with The Independent before the match he
had said: “I can win. I have a better programmer than Chinook. His was
Jonathan, mine was the Lord.” 22
There can be little doubt that, since Tinsley's death in 1995, Chinook
has been the world's strongest Checkers player. All that now remains

22 A rematch was started in Boston in 1994, but after four games, all of which were drawn, Tinsley
was hospitalized and diagnosed with cancer, from which he died six months later.