Before Sunday, this year's college coaching carousel had two emerging themes: early dismissals and prominent coaches staying put.
The number of coaches re-signing had started to catch up to the number of coaching changes. Among the notables not leaving: Minnesota's P.J. Fleck, UTSA's Jeff Traylor, Penn State's James Franklin, Liberty's Hugh Freeze, Michigan State's Mel Tucker, Oregon State's Jonathan Smith and Wake Forest's Dave Clawson. Boston College's Jeff Hafley added his name to the list Monday, and Kentucky's Mark Stoops followed Tuesday.
Then, on Sunday, Riley accepted the USC job and sent the carousel spinning off its axis. A day later, Notre Dame coach Brian Kelly, who turned 60 last month and seemed to be in the legacy-solidifying stage of his career, dramatically left for LSU.
Moves like Riley's and Kelly's simply don't happen very often. Oklahoma hasn't had a coach leave for another college job since 1947. Notre Dame hasn't had it happen since 1907.
This historic carousel undoubtedly will be remembered for the two who left, but don't forget about the group that stayed.
As the coaching news continues to roll in, here are seven observations about the carousel to date, and what might be coming in the days and weeks ahead.