First computer to beat a world chess champion under regular time controls

On May 11, 1997, world chess champion Garry Kasparov was beaten by the IBM chess computer Deep Blue – a superpowerful parallel processor capable of evaluating 200 million board positions every second, and holding in its memory details of 700,000 past games played by grandmasters. Kasparov won the first game of the match but lost the second. The next three games were drawn, making the sixth and final one the decider. However, Kasparov made an early mistake that proved fatal. Although he had been defeated in 1994 by the another computer, called "Chess Genius", that match was played under "rapid chess" rules, in which players have less time in which to act. This was the first time a reigning world champion had been out-manoeuvred by a computer under regular time controls.