30. Fedor Emelianenko
There was a time when ‘The Last Emperor’ was the most feared fighter on the planet. But after a long career, age finally caught up with Emelianenko. He never fought in the UFC, which arguably helped build up his mystique. After going undefeated for nine years, he ran into Fabricio Werdum in 2010 and went on a three-fight losing streak. But he rebounded and continued to fight into his forties.

This amount of brain trauma isn’t good for anybody and when a fighter is as rich and successful as Fedor, it begs the question of why he continued for so long. Nobody likes to see a legend suffer knockout losses. Also, these late defeats can affect their legacy as well. The bad memories often replace the old ones and change the narrative about their careers.