I'm thinking 30-20, Bama of course, because both teams bog down and kick FGs. ND has scored 3 TDs per game (36) and kicked 2 FGs per game (24). Bama has scored 65 TDs and kicked 15 FGs. Both defenses are capable of turning the other team's TD drives into FG drives. ND has been especially good at that giving up 10 TDs and 18 FGs. Bama not as good at 18 and 5.
The averages of all of that say 24-18 Bama. 30-20 is close enough.