Garry Kimovich Kasparov (born Garik Kimovich Weinstein on 13 April 1963) is a Russian chess grandmaster, political activist and writer, who was the World Chess Champion from 1985 to 2000. His peak FIDE chess rating of 2851, achieved in 1999, was the highest recorded until being surpassed by Magnus Carlsen in 2013. From 1984 until his retirement from regular competitive chess in 2005, Kasparov was ranked the world's No. 1 player for a record 255 months overall. Kasparov also holds records for the most consecutive professional tournament victories (15) and Chess Oscars (11). Kasparov became the youngest undisputed world champion in 1985 at age 22 by defeating then-champion Anatoly Karpov, a record he held until 2024. He defended the title against Karpov three times, in 1986, 1987 and 1990. Kasparov held the official FIDE world title until 1993, when a dispute with FIDE led him to set up a rival organisation, the Professional Chess Association. In 1997, he became the first world champion to lose a match to a computer under standard time controls when he was defeated by the IBM supercomputer Deep Blue in a highly publicised match. He continued to hold the "Classical" world title until his defeat by Vladimir Kramnik in 2000.