Computer chess-playing system designed by IBM. In 1996 Deep Blue made history by defeating Garry Kasparov in one of their six games the first time a computer had won a game against a world champion under tournament conditions. In the 1997 rematch, it won the deciding sixth game in only 19 moves; its 3.5-2.5 victory (it won two games and had three draws) marked the first time a current world champion had lost a match to a computer under tournament conditions. In its final configuration, the IBM RS6000/SP computer used 256 processors working in tandem, with an ability to evaluate 200 million chess positions per second