Deep Blue was a chess-playing computer developed by IBM. It is known for being the first piece of artificial intelligence to win both a chess game and a chess match against a reigning world champion under regular time controls.
Deep Blue won its first game against a world champion on February 10, 1996, when it defeated Garry Kasparov in game one of a six-game match. However, Kasparov won three and drew two of the following five games, defeating Deep Blue by a score of 4–2. Deep Blue was then heavily upgraded, and played Kasparov again in May 1997. Deep Blue won game six, therefore winning the six-game rematch 3½–2½ and becoming the first computer system to defeat a reigning world champion in a match under standard chess tournament time controls. Kasparov accused IBM of cheating and demanded a rematch. IBM refused and retired Deep Blue.