It hurts just to watch this highlight reel of Mike Tyson's knockouts
Has any boxer ever hit as hard as Mike Tyson?
The former heavyweight exploded onto the boxing scene back in the 1980s, winning his first 19 fights by KO, and becoming the youngest ever heavyweight champion of the world when he was just 20.
Tyson was a knock-out specialist, winning 44 of his 58 fights by KO over a 20 year career filled with controversy, personal problems and a stint in prison.
There was also that time he bit a part out of opponent Evander Hollyfield's ear.
The Brooklyn native retired in 2005, and is now 49, but it's safe to say no heavyweight boxer has come close since to matching his KO feats.
It almost hurts just to watch some of these clips.