A 31-17 score is a 14 point spread and a 48 point total. By the same token if a game has a 14 point spread and a 48 point O/U it can be assumed the oddsmaker is figuring a 31-17 score. What else could it be?
I use this to predict Bama scores if I think the oddsmaker is anywhere near correct. I usually just use 41-14. My birth year and birth date.

That's what I have this week.