12. Romeo Crennel
Crennel is a good man and an excellent assistant (via Sportscasting). However, he failed to convince as a head coach in the NFL. Firstly, he endured mixed fortunes with the Cleveland Browns. Then the Chiefs hired him and promoted him to interim head coach in 2011. This came after the team fired Todd Haley. Crennel won two out of three games and the Chiefs gave him the job permanently.

But his short tenure was disastrous. First, the team wasn’t good enough with a 2-14 record and showing no signs of improvement. Then, Crennel had to deal with Jovan Belcher’s suicide. He witnessed the tragic death of the Chiefs star. Incredibly, Kansas won their next game after this incident. In the end, he was almost happy to depart after a tumultuous season.