16-0 is with a bye! If we went undefeated but ended up ranked fifth of the conference champs (pretend PAC-12 still existed and all P5 champs went undefeated), we'd have to go 17-0 like the '72 Dolphins.
And post that we're going 15-0 and winning a championship after seeing practise highlights.
With the CFP expansion, undefeated is now 16-0.
You're welcome