A look back at coaching changes from last offseason offers perspective.
Teams Going 6-10 or Worse in 2010
Thirteen NFL teams finished the 2010 season with six or fewer victories.
Five hired new head coaches. Four of those five -- San Francisco, Carolina, Denver and Tennessee -- improved in the standings. One, Cleveland, got worse. The five teams produced a net gain of 17 victories from 2010.
Those improvements provide evidence to support coaching changes. There is more to this story, however.
Two of the 13 teams in question made changes during the 2010 season, then decided to keep their interim coaches. One, Dallas, improved by two victories. The other, Minnesota, got worse by three victories.
Here is the interesting part: Five of the six teams to keep their coaches after finishing 6-10 or worse -- Cincinnati, Detroit, Houston, Arizona and Buffalo -- improved their totals for victories. One, Washington, got worse by a single game. These six teams to stay the course produced a net gain of 17 victories from 2010, same as the five teams that hired brand new coaches.
Counting Dallas and Minnesota among the teams with new head coaches tips the balance in favor of teams that stayed the course. Put another way, teams replacing the head coaches they took into the 2010 season improved by 2.28 victories on average. Teams staying the course after finishing 6-10 or worse improved by 2.83 victories on average.
We can amplify certain aspects of these numbers to justify decisions one way or another. I present them merely as balance to natural perceptions that coaching changes are the key to subsequent improvement.
The 49ers obviously made the right move in hiring Jim Harbaugh to replace Mike Singletary. They improved from 6-10 to 13-3 and we could all see ways the coaching was improved. Other situations are more difficult to evaluate. Tennessee improved from 6-10 to 9-7 after replacing Jeff Fisher with Mike Munchak, but no one would have been shocked if Fisher had also gone 9-7 with a new veteran quarterback behind center.
The Rams will almost certainly improve after firing Steve Spagnuolo. It'll most likely take dramatic gains to convince me coaching was a primary reason for them.