1988 to 2000: 887 wins, 2 losses, 4 Olympic Gold medals.
For wrestling, which is arguably the most grueling and physically demanding sport on earth (brutal training and competition, basically guaranteed major injuries over time) Karelin’s reign was straight up preposterous and unheard of. Wrestling ain’t like basketball or other sports, you don’t just have a 15-20 year career undoing it at the highest level, the human body ain’t made to take that kind of punishment. He is absolutely up there with the all-time greats in all of sport, both longevity and just sheer dominance wise.