Kasparov, Garry

Garry Kasparov became the youngest undisputed World Champion in 1985 at age 22 by defeating Anatoly Karpov, and held the title until 2000, spending a record 255 months ranked world No. 1. Known for his ferocious attacking style, unmatched opening preparation, and extraordinary feel for dynamic positions, he achieved a peak rating of 2851 that stood as the record for over thirteen years. His 1997 match against IBM's Deep Blue was a landmark moment in the history of artificial intelligence, and he later became a prominent author and political activist.