Garry Kimovich Kasparov is a Russian chess grandmaster, a former World Chess Champion, writer and political activist, considered by many to be the greatest chess player of all time.
Kasparov became the youngest ever undisputed World Chess Champion in 1985 at the age of 22 by defeating then-champion Anatoly Karpov. He held the official FIDE world title until 1993, when a dispute with FIDE led him to set up a rival organization, the Professional Chess Association. He continued to hold the "Classical" World Chess Championship until his defeat by Vladimir Kramnik in 2000. He was the first world champion to lose a match to a computer under standard time controls, when he lost to Deep Blue in 1997.
Kasparov's ratings achievements include being rated world No. 1 according to Elo rating almost continuously from 1986 until his retirement in 2005. He achieved a peak rating of 2851, which was the highest recorded until 2013. He was the world No. 1 ranked player for 255 months, nearly three times as long as his closest rival, Anatoly Karpov. Kasparov also holds records for consecutive tournament victories and Chess Oscars.