Every winter, a wave of programs change head coaches. The assumption inside a lot of front offices is that the new hire's scheme is what shakes a roster loose. Pro-style teams that install an air raid lose their downhill runners. 4-3 teams that flip to a 3-3-5 lose linebackers who don't fit. We tested that assumption directly against roughly 85 FBS head-coaching changes from 2021 to 2023, isolating scheme change from staff change for the first time in our research library.
The scheme change turned out not to matter, statistically. Programs that shifted their offensive identity by a wide margin, measured by year-over-year swings in offensive line yards and power-success rate, showed no meaningfully different portal departure rate than programs that kept the same offense.
What did move the number was simply whether the head coach changed. Across Power 4 and Group of 5 program-seasons from 2021 to 2024, programs with a new head coach averaged 22.68 transfer departures the following season. Programs that kept the same head coach averaged 17.93. That is a 26.5% increase tied to the coaching change alone, measured across 100 coaching-change program-seasons against 380 stable ones.
That is a real signal for anyone planning around a coaching change, whether you are the incoming staff working scholarship math or a rival program scouting the portal for opportunity. The instability that triggers exits is not about which plays get called. It is about who is calling them.
Methodology: we cross-referenced head coaching changes (college_coach_seasons, resolved to the coach of record each season so mid-year interim staffs are not double-counted) against FBS offensive scheme shifts (offensive line yards and power-success rate, year over year) and Power 4 / Group of 5 portal departures by position group. The 2021 to 2023 head-coaching-change count lands at roughly 85, in line with the public coaching-carousel tallies for those years. Full findings: RI-RF148 and RI-RF160, approved for publication in our research library.