Land mines for Texas Longhorns, more

Matt Barkley leads the Trojans' offense, but stopping QBs of his caliber will be USC's key this fall. Chris Morrison/US Presswire

Every team in ESPN.com/ESPN The Magazine's preseason top 25 poll made rank because they have lots of positive things going for them. But nobody's perfect, and in order to identify the things that could hold these teams back, we sent them through ESPN Insider's Eliminator model.

This week we'll examine five teams per day, picking out the statistical weakness that could trip up each team, and the three teams/games that could exploit them (the land-mine games, if you will). Each stat is drawn from our Eliminator model and thus is a category that correlates strongly to success in college football. The minimum benchmark met by each conference and BCS champ, and the average of past champs, is provided for each.

Today, we tackle the teams ranked No. 25 through No. 21.

25. USC Trojans (8-5 in 2010)

Statistical category: Defensive passing efficiency

BCS benchmark: 133.7 passer rating allowed (101.8 average)

Pac-12 benchmark: 118.8 (105.0 average)

USC in 2010: 135.9

Tracking how the Trojans will fare in the Pac-12 and BCS races may seem futile given their bowl ban, but we'll look at them here thinking in terms of how they'll fare in the conference standings.

USC had plenty of weaknesses in 2010, but none was more glaring than its inability to defend the pass (it's important to pay attention to the average figure for this BCS benchmark, as Auburn's championship run last season was an outlier in the passing efficiency D area).

The Trojans' yards per attempt allowed numbers and passing efficiency D were both poor last season, and the latter is a problem that could be exacerbated in 2011 by the fact the Pac-12 features five of the nation's 22 best QBs in passing efficiency rating (among returning passers). Losing Shareece Wright, the Trojans' leader in pass break-ups in 2010, to the NFL doesn't make things any easier for USC.

Land mines: at Notre Dame, Stanford, at Oregon

In a loss to Notre Dame last season, USC watched the Irish's star receiver, Michael Floyd, catch 11 passes, including a touchdown.

Andrew Luck presents an obvious challenge for any pass D, and Oregon's Darron Thomas is no slouch, either. The Ducks' prolific running game may get most of the attention, but check out Thomas' stats in the passing department: ninth nationally among returning starters in passer rating, and 15th in yards per passing attempt.