Garry Kasparov
Kasparov became the youngest non-disputed World Chess Champion in 1985 at the age of 22. He held the official FIDE world title until 1993, when an argument with FIDE led him to set up a rival company, the Professional Chess Association. He continued to hold the "Classical" World Chess Championship until his defeat by Vladimir Kramnik in 2000. Kasparov lost a match (a series of chess games) against Deep Blue, a computer made by IBM, in 1997. Lately, retired from competition, he has been coaching Magnus Carlsen, the young player from Norway who is the current world #1.