Red Flags: 5 college football teams on upset alert in Week 8

3. Air Force Falcons

Opponent: at Navy | Time: Saturday, Oct. 21, Noon ET (CBS) | Spread: AFA -10.5

To start out painting the picture of why one of the 11 undefeated teams remaining in college football, Air Force, is in danger of an upset on the road against a 3-3 Navy team, you first need to be enlightened by one of the greatest betting trends in the history of the sport.

Shoutout to Tom Fornelli of CBS Sports (the proverbial godfather of this stat), but since 2005 when service academies play against one another, the under in those games is an astounding 42-10-1, meaning that it goes under the total more than 80% of the time. And for further context, that trend has continued even with totals in the mid-30s (such as this one that currently sits at 34.5.

The reason for that is multi-faceted, though. For one, there are limited possessions with every service academy -- obviously Air Force and Navy included -- running the triple-option. That keeps the clock moving, it breeds long, sustained drives, and there is just fewer opportunities for these teams to score. Beyond that and more simply, though, these teams running the triple-option makes them uniquely prepared to face a triple-option offense defensively, something most teaems in the country aren't privy to.

Air Force has been by far the better team between these two. But the Falcons come into this game with starting QB and second-leading rusher Zac Larrier out. Not having him is a downgrade for the offense. Though Navy is also without Tai Lavatai, their starter, the drop-off is far less dramatic.

With the Midshipmen defense prepared for this offense and Air Force potentially taking a step back without Larrier, Navy could be love to shock the world. Even if that happens, it could (and maybe should) be a closer game than expected.