At top-level (Division I) college football programs, chances are only about 50-50 that a player's head coach as a freshman will be his head coach when he is a senior. So it's a good idea for high school football recruits to base their commitment decisions on more than how they like those coaches personally. Recruits should also consider whether the college itself is a good fit for them academically, socially, and geographically.
Looking at the numbers, head coach turnover averaged nearly 19 percent annually over the past three years (2009-2011) at Division I Football Bowl Subdivision (formerly Division I-A) programs, according to NCAA statistics. And head coach turnover averaged more than 13 percent annually over the last three years at Division I Football Championship Subdivision (formerly Division I-AA) programs. No data is available for lower-division programs.
So taken together, this data indicates that there were head coaching changes at nearly one-half of NCAA Division I football programs over the most recent three-year period (2009-2011). And that doesn't take into account other coaching changes among offensive coordinators, defensive coordinators, and other assistant coaches. Many of them leave and join college football coaching staffs every year, even if the head coach remains the same at a given program.
Assistant coaches are often the primary points of contact for college players, so a player's college football experience can be greatly affected when those assistants leave and new ones arrive -- another great reason for taking into account other factors, such as academics, social issues, and location -- when recruits try to determine where to play college football.
Coaching changes often begin in late November and December, soon after the end of a football season in which a college team might fail to meet the expectations of fans, alumni, and other supporters.