Computer chess built in by the evaluation function and pruning/extension rules began to match the best players in the world. It turned out to produce excellent results, at least in the field of chess, to let computers do what they do best (calculate) rather than coax them into imitating human thought processes and knowledge. In 1997 Deep Blue defeated World Champion Garry Kasparov, marking the first time a computer has defeated a reigning world chess champion in standard time control. Computer chess programs consider chess moves as a game tree. In theory, they examine all moves, then all counter-moves to those moves,
Human–computer chess matches first game (Deep Blue – Kasparov, 1996, Game 1), the first time a reigning world champion had lost to a computer using regular time controls. However, Kasparov regrouped to win three and draw two of the remaining five games of the match, for a convincing 4–2 match victory. In May 1997, an updated version of Deep Blue defeated Kasparov 3½–2½ in a highly publicized six-game match. Kasparov won the first, lost the second, and drew the next three. The match was even after five games but Kasparov was crushed in Game 6. This was the first time a computer had