Usually by the time a head coach reaches his fourth year in charge of a program everything is finally and exclusively "his." The players he has recruited now make up a majority of the team, those players have become fully acclimated to the schemes and systems he has installed, and the coaches he has brought over now have some continuity within the program. It can be difficult for players to get in any kind of a rhythm if new coaches and schemes are constantly on their way in and out. Nathan Scheelhaase, former Illinois quarterback who had three offensive coordinators in four years in Champaign, may tell you otherwise, but as a general rule of thumb consistency is the key.