Average nERD: -9.08 (69th)
Average Win Differential: -4.50 (59th)

When you pass up Aaron Rodgers in your first season as a head coach -- due to too much attitude -- in favor of Alex Smith because he was introspective and shied away from confrontation, things can only go downhill from here. Mike Nolan worked as a defensive coordinator for 11 years before the San Francisco 49ers brought him on as head coach. He advocated for the short-armed Smith, and this lack of offensive fit for the sake of locker room chemistry led the 49ers to two seasons of sub-.400 win percentage football in four years. Nolan was fired in the middle of the 2008 season, but the Niners would only achieve 7-9 as their high point in the Nolan era.

The sad thing is how much worse he was than his stats suggest. Of the 73 coaches this study examined, Nolan’s average nERD in a season ranked fifth-worst. His 2005 squad, which went 4-12, had the sixth-worst single-season nERD score of all time: -13.44. 2007 wasn’t much better, at -11.97, and he would never have a season with a positive score in this analytic.