Kasparov-Deep Blue 1997

Kasparov-Deep Blue 1997 was a six-game rematch played in New York in May 1997. Garry Kasparov was the reigning world champion, and Deep Blue was an IBM computer built specifically to play chess. The match used standard tournament time controls, meaning slow games in which each side had hours, rather than minutes, to make its moves.

Kasparov won Game 1 and Deep Blue won Game 2. The next three games were draws, so the contest was decided in the sixth and final game. Deep Blue won it and took the match 3.5-2.5 . The distinction from 1996 matters: Deep Blue won one game in the earlier meeting, but Kasparov recovered and won that match 4-2.

Preparing for the rematch meant more than speeding up calculation. In their technical report, members of the team explained that they had devoted most of their work between the matches to improving evaluation: the mechanism that assigned values to the positions the system calculated. Joel Benjamin and other grandmasters also helped prepare openings and identify weaknesses through test games. Deep Blue combined variation search, evaluation and chess knowledge. It was a specialized system, similar in purpose to a chess engine, not a general intelligence.

More than a mistake in the final game

Kasparov’s opening win had offered a chess argument, not just a point. William Hartston described his opening as a way of avoiding early complications against the computer. After a manoeuvring struggle, Deep Blue gained a rook for a bishop, but White’s advanced pawns and king safety mattered more. The machine’s material gain was not enough to stop those pawns.

Game 2 prevented that success from becoming a recipe for the entire match. In their account, Jonathan Schaeffer and Aske Plaat emphasized the quality of Deep Blue’s positional play, which restricted the champion’s pieces. The program could pose problems that went beyond finding an immediate tactic. After the three draws, both sides entered the final day with a chance to win.

Game 6 was very different from that first manoeuvring struggle. With the king still uncastled, 7...h6 allowed the known sacrifice 8.Nxe6; Deep Blue had not invented it during the game. The attack led to Kasparov’s resignation after 19.c4. The reasons for 7...h6 remain disputed. His opening error decided that game, but it does not sum up the entire match.

The achievement and its public image

Deep Blue became the first computer system to defeat a reigning world champion in a match under standard time controls. IBM’s web broadcast provided live moves and a transcript of the commentary, while coverage presented the contest as a symbolic test between humanity and machine. What the six games established was more specific: a specialized system, prepared by a team, could beat the champion in that competitive format.