8. Rod Marinelli
Marinelli took over the Detroit Lions job in 2006. He lasted for three seasons before his inevitable demise. Nobody foresaw how bad it would be. This was a disastrous reign that stained the legacy of the franchise forever. That’s because they became the first team to lose 16 games in a season. They went winless in 2008 after failing to win a single match (via Detroit Free Press).

There are arguments that the 2008 Lions weren’t the worst team ever. But there is no way to erase that zero. Unfortunately, Marinelli led them at this time because he’s a great defensive coach. He had success with Tampa and Dallas as a defensive line coach and coordinator. Unfortunately, Detroit was a poor team and he failed to revitalize them.