1. Isaiah Thomas
Some players just can’t cut it as a head coach. That was exactly the case for Thomas, who is a Pistons legend. A 12-time All-Star and a two-time NBA champion, there weren’t many players out there with his level of experience. But both of his NBA coaching jobs – with the Pacers and the Knicks – ended in disaster.

His time with the Knicks was especially bad. They had the highest payroll in the league, but the second-worst record. As well as that, he lost an $11.5 million sexual harassment lawsuit. Meanwhile, his actual coaching was disastrous. After 59 losses in the 2007-08 season, the fans hated him. Finally, the Knicks cut their losses and fired him.