19. Jon Jones
The UFC has a history of contract holdouts because they grossly underpay their fighters. Jones was one of their biggest stars but came with a lot of baggage. After vacating the 205 lb. title, he announced his move up to heavyweight. Fans hoped for a super fight between Jones and Francis Ngannou but the UFC disappointed them. They refused to meet Jones’s demands so he sat out.

There are two sides to this story. First, the UFC is infamously cheap and refuses to make their best athletes into big stars. They want brand ambassadors instead of global icons. Meanwhile, Jones is a problematic individual. His doping record and legal issues damage his leverage. It’s difficult to see him winning this war of numbers with the promotion (via SportsJoe).