Deep Blue versus Kasparov

On February 10, 1996, Deep Blue became the first machine to win a chess game against a reigning world champion (Garry Kasparov) under regular time controls. Deep Blue - Kasparov, 1996, Game 1 is a famous chess game. However, Kasparov won three games and drew two of the following games, beating Deep Blue by a score of 4–2. The match concluded on February 17, 1996.

Deep Blue was then heavily upgraded (unofficially nicknamed "Deeper Blue")[9] and played Kasparov again in May 1997, winning the six-game rematch 3½–2½, ending on May 11, finally ending in game six, and becoming the first computer system to defeat a reigning world champion in a match under standard chess tournament time controls.

The system derived its playing strength mainly out of brute force computing power. It was a massively parallel, 30-node, RS/6000, SP-based computer system enhanced with 480 special purpose VLSI chess chips. Its chess playing program was written in C and ran under the AIX operating system. It was capable of evaluating 200 million positions per second, twice as fast as the 1996 version. In June 1997, Deep Blue was the 259th most powerful supercomputer, capable of calculating 11.38 gigaflops.

The Deep Blue chess computer which defeated Kasparov in 1997 would typically search to a depth of between six and twelve plies to a maximum of forty plies in some situations. An increase in search depth of one ply corresponds on the average to an increase in playing strength of approximately 80 Elo points. Levy and Newborn estimate that one additional ply increases the playing strength 50 to 70 points (Levy & Newborn 1991:192).

Deep Blue's evaluation function was initially written in a generalized form, with many to-be-determined parameters (e.g. how important is a safe king position compared to a space advantage in the center, etc.). The optimal values for these parameters were then determined by the system itself, by analyzing thousands of master games. The evaluation function had been split into 8,000 parts, many of them designed for special positions. In the opening book there were over 4,000 positions and 700,000 grandmaster games. The endgame database contained many six piece endgames and five or fewer piece positions. Before the second match, the chess knowledge of the program was fine tuned by grandmaster Joel Benjamin. The opening library was provided by grandmasters Miguel Illescas, John Fedorowicz and Nick de Firmian. When Kasparov requested that he be allowed to study other games that Deep Blue had played so as to better understand his opponent, IBM refused. However, Kasparov did study many popular PC computer games to become familiar with computer game play in general.