Chinook

Chinook is a computer program for checkers built by Jonathan Schaeffer and colleagues ^[1]. It is best known for two linked claims: it was the first computer program to win a human world championship in any game, and its completed version cannot be beaten ^[1].

由来

Schaeffer started the Chinook project in 1989 with a specific goal: win the human world checkers championship ^[1]. The program earned the right to play for the championship in 1990 and lost the championship match in 1992 ^[1]. In that 1992 match against Marion Tinsley, Chinook beat Tinsley twice, but computer glitches led to a forfeit, according to Scientific American ^[4]. The early program was not yet the final, unbeatable database. CBC reported that Chinook originally used a heuristic approach based on rules of thumb from top checkers players, and that in the mid-1990s it still sometimes lost games ^[3].

主要特点

The early Chinook therefore played by guidance rather than by complete knowledge ^[3]. A heuristic is a practical rule that helps a program choose moves without proving the best move in every case. The finished program changed character: it no longer needs heuristics and has become a database of information that knows the best move in every situation of a game ^[1]. Building that knowledge took large-scale computation. An average of 50 computers, with more than 200 running at peak times, were used every day to compute the knowledge needed for Chinook ^[1]. The solving effort built a database of all 39,000 billion arrangements with 10 or fewer pieces on the board ^[2]. Within that set of positions, the program could consult stored information instead of estimating.

比赛与结果

In 1994 Chinook won the human world championship ^[1]. It became the first computer program to win a human world championship in any game, a feat recognized by Guinness World Records ^[1]. The 1994 rematch with Tinsley was unusual: Scientific American says Tinsley withdrew after six drawn games because of health problems ^[4]. Chinook remained undefeated until it was retired in 1997 ^[1]. Schaeffer restarted the project in 2001 ^[1].

在发展中的位置

Chinook matters because it joined a concrete human competition to a long solving effort ^[1]. The early losses and the later unbeatable version mark the change from a heuristic player to a stored, completed body of knowledge ^[3][1]. The project also made the scale of game solving visible: many computers ran daily, and the result was a database covering all arrangements with 10 or fewer pieces ^[1][2]. Its 1994 title and Guinness recognition made it a public example of a computer program winning a human world championship in a game ^[1]. The later restart in 2001 continued the project after its retirement ^[1]. In that sense Chinook is both a competitive program and a solved-position archive: a program built to win a championship, and a finished system whose answers for covered positions come from a database rather than from heuristics ^[1][2].