Earlier this week, CoachingSearch looked at the longest-tenured assistants in FBS. Now, here’s a look at the tenure of every FBS head coach. Illustrating the amount of turnover in the profession, 108 of the 129 FBS head coaches have been hired since 2010, and 88 have been hired in the past four years. That means more than 2/3 of all head coaches have been hired since 2013.Some veteran coaches who left the list this offseason included Frank Beamer (1987), Gary Pinkel (2001), George O’Leary (2004), and Steve Spurrier (2005).First, the longest tenured coach in each conference:AAC: Ken Niumatalolo (Navy) -...