It looks like Ohio State would have missed the 12 team playoff only four times since 2000.
2000 and 2001, John Cooper's final season and Jim Tressel's first. Then 2004, the Justin Zwick year. Finally 2011, the Luke Fickel year.
I suppose it's possible that 2000 could have maybe been a fringe bubble team, with two of their three regular season losses being against ranked teams.