Where No. 5 Oregon, No. 6 Ole Miss are weakest against upset-minded James Madison, Tulane in CFP first round

Few are giving College Football Playoff No. 20 Tulane Green Wave (11-2, 7-1 in American) or No. 24 James Madison Dukes (12-1, 8-0 in Sun Belt) much of a chance in their CFP first-round games.

But their showdowns at the No. 6 Ole Miss Rebels (11-1, 7-1 in SEC) and No. 5 Oregon Ducks (11-1, 8-1 in Big Ten), respectively, will be decided on the field, not through podcasts and blog posts. 

So, how can Tulane and James Madison pull off the biggest upsets of the CFP era? Below, we take a look at where Ole Miss and Oregon are most vulnerable headed into Saturday's games.

Ole Miss Rebels

Biggest weakness: Rush defense | Three opponents gained over 200 rushing yards against Ole Miss this season. Among this year's CFP teams, only the No. 7 Texas A&M Aggies (11-1, 7-1 in SEC) allowed more (four). Overall, the Rebels are No. 69 in the country against the run, allowing 150.5 yards per game.

In a Week 4 blowout loss to Ole Miss, the Green Wave successfully ran the ball, finishing with 178 yards on 39 carries (4.6 yards per attempt). They were ultimately undone by an explosive Ole Miss offense and quarterback Jake Retzlaff's worst passing game of the season. He missed on his first nine attempts and was pulled for backup Brendan Sullivan in the fourth quarter.

Ole Miss' big-play offense is the perfect antidote to a ball-control attack Tulane might deploy, but that's where losing head coach Lane Kiffin, who infamously left earlier this month to accept the same position at LSU, could hurt. It's unclear what impact his departure will have, but if the Rebels are out of sync at all and forced into lengthy possessions, that would shorten the game, playing to Tulane's advantage.

Oregon Ducks

Biggest weakness: Run blocking | Critiquing Oregon feels like nitpicking. The Ducks are one of the most complete teams in the country, elite in all three phases. But if there's something to gripe about, it would be their run blocking.

In October's home loss to No. 1 Indiana Hoosiers (13-0, 9-0 in Big Ten), Oregon was held to a season-low rushing 81 yards, averaging 2.7 yards per attempt. In its most recent game against Washington (9-4, 5-4 in Big Ten), it was contained to 2.5 yards per attempt.

Oregon's top three backs — Jordon Davison, Dierre Hill Jr. and Noah Whittington — gain the majority of their yardage after contact, per Pro Football Focus data, and if they're unable to break tackles consistently against a stout James Madison rush defense, it could make the Ducks one-dimensional.

The Dukes are second in the country in rush defense (76.2 yards per game) and one of three teams (Texas Tech, Oklahoma) to allow fewer than 1,000 yards entering the CFP first round.

Per PFF stats, defensive tackle Mychal McMullin has the sixth-highest stop rate (11.9 percent), defined as tackles that constitute a failure for the offense, among interior linemen with at least 120 run-play snaps this season. Edge-rusher Aiden Gobaira ranks third (13.1 percent) among players at his position in the same metric.

James Madison will face its stiffest competition all season this Saturday (7:30 p.m. ET, TNT/truTV/HBO Max). But it's arguably strongest where Oregon is the most flawed, giving it a chance to expose the Ducks' weakness.