Defeating the World Chess Champion
After defeating Deep Blue in 1996, Garry Kasparov issued a rematch challenge for the following year. To prepare, the team tested the machine against several Grandmasters, and doubled the performance of the hardware.
A six-game rematch took place in New York in May 1997. Kasparov won the first game but missed an opportunity in the second game and lost. Kasparov never recovered his composure and played defensively for the remainder of the match. In the last game, he made a simple mistake and lost, marking May 11, 1997, as the date on which a World Chess Champion lost a match to a computer.
There have since been two other matches between a computer and a World Chess Champion. Both have ended in a tie.