Deep Blue (chess computer) of the following five games, beating Deep Blue by a score of 4–2 (wins count 1 point, draws count ½ point). The match concluded on 17 February 1996. Deep Blue was then heavily upgraded (unofficially nicknamed "Deeper Blue") and played Kasparov again in May 1997, winning the six-game rematch 3½–2½, ending on 11 May. Deep Blue won the deciding game six after Kasparov made a mistake in the opening, 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 from brute force computing
Reversi game has been particularly attractive to programmers. Therefore, the best Othello computer programs have easily defeated the best humans since 1980, when the program "The Moor" beat the reigning world champion. In 1997, Logistello defeated the human champion Takeshi Murakami with a score of 6–0. Analysts have estimated the number of legal positions in Othello is at most 10, and it has a game-tree complexity of approximately 10. Mathematically, Othello still remains unsolved. Experts have not absolutely resolved what the outcome of a game will be where both sides use perfect play. However, analysis of thousands of high quality games