Michael Gerard Tyson (New York, June 30, 1966) is a former American boxer, nicknamed "Iron Mike", who is considered one of the best boxers of all time, world heavyweight champion from 1986 to 1990, with a brief stint in 1996. Tyson won his first 19 fights by knockout, 12 of them in the first round. In 1986, at the age of 20 years 4 months and 22 days, he won the WBC crown against Trevor Berbick, becoming the youngest world champion of heavyweights, a record that still remains unbeaten. A year later he also won the WBA and IBF titles, becoming undisputed champion and the first heavyweight to unify the world championships. His defeats were also memorable, especially those against Evander Holyfield: they went down in history the rematch when Tyson was disqualified for biting his opponent's ears, detaching a piece of cartilage from his right ear.