Chuck Pagano
The Colts finished 2-14 in 2011 with Peyton Manning on the sidelines due to a neck injury and Curtis Painter taking the reigns at quarterback. That season got Jim Caldwell fired and ushered in the Chuck Pagano era.
Pagano went 11-5 in his first season with the Colts with a sensational rookie quarterback named Andrew Luck. Their 11-5 record was a bit misleading as they were outscored by 30 points on the year, but a playoff appearance as a first-year head coach is almost always deemed a success.