Most college football players will not finish their career with the coach who recruited them
When Steve Spurrier explained why he was resigning as the football coach at the University of South Carolina, one of the reasons he gave was his age and its impact on recruiting, noting that high school players want to know if the coach is going to be at the school the player's entire collegiate career.
It turns out, college players playing their entire career under one coach is not nearly as common most of these high school kids realize.
In order for a player to complete his college career under the same coach that recruited him, the coach needs to stay at the school at least six years, the recruit's senior year of high school (presumably when the player is recruited) and five years of college eligibility. That rarely happens.
In fact, 72% (92) of the 129 current FBS (formerly Division I-A) coaches have been at their current school less than six years, based on data collected by CoachingSearch.com. In other words, at least 72% of 5th-year seniors are playing under a different coach than the one who recruited them, a number that is likely higher due to some recruits committing before their senior year of high school.
So when a coach promises a recruit that he will be there all five years, it is actually unlikely to be true.