Stats are deceiving.
A simple look at yards per rush, would tell you that the USC Trojans give up 3.48 yards per rush, a number good for 26th in the country. Comparatively, the Oregon Ducks give up 3.73 yards per rush, which is good for 43rd in the country. Conventional wisdom would tell you that the Trojans have a better run defense than the Ducks. Yet, as Kalon pointed out earlier today, the advanced stats, in this case S&P+, rank USC 60th against the run and Oregon 5th.
This is largely because of how S&P+ weights the statistics. USC held Hawaii--105th in the nation in rushing--to 1.8 yards per carry in a game that was over early (S&P+ discredits garbage time stats). Its not a coincidence that SC has faced five teams that rank 85th or worse in yards per rush--and have held all of those to a 3.4 yard average or less. The two competent rushing teams SC has played have both exceeded their season averages against SC. Stanford, with a season average of 4.3 ypc, rushed for 5.5 against SC. Arizona outperformed theirs as well, by a margin of 5.1-4.8. Its not surprise that USC lost both of those games, and both are weighed heavily by S&P+, as they were both close games where starters played the whole way. Oregon is ranked #1 in the country at 6.18 yards per rush.
Meanwhile, Oregon's defensive ypc stats are skewed slightly by the Arkansas State performance--ASU rushed for 6.1 yards per carry, but that game was over after a quarter and the Red Wolves faced mostly backups and walkons in their first action for the bulk of that game. The same could be said of the Colorado game, where the Ducks gave up 4.5 yards per rush. S&P+ throws a lot of that out as being irrelevant. Look at the two games where the starters had to play into the third quarter: Arizona, with their 4.8 ypc mark on the season, was held to 2.8 yards per carry in Eugene. Washington State, which is the worst rushing offense in the country at a woeful 1.6 ypc, was still held two yards below that by the Oregon starters, averaging -0.4 ypc against the Ducks.
Competent running teams can, and have run on the Trojans, and there is no team more competent at running the football than Oregon. We saw what trouble Arizona gave USC last weekend--not just Kadeem Carey, but Matt Scott as well. Well, as Stuart Mandel tweeted, Oregon's offense is Arizona's perfected. Oh yeah, the Ducks have a better defense than the 'Cats, too.
USC's defense is very aggressive (8th in sacks, 22nd in TFL), and tied with Oregon for 4th in turnovers. Oregon can be a turnover prone team offensively, and a rash of turnovers could prove to be the great equalizer, so they must be avoided. But aggression can often backfire against Oregon given the inherent deception in the offense, so you may see a more conservative style in favor of staying home and making sure tackles.
As we saw last season, USC has a small but speedy linebacking corps that was built to counter what Oregon does. Dion Bailey and Hayes Pullard played out of their minds in last year's contest, but were bolstered by a dominant defensive line that simply doesn't exist for the Trojans this season. And we saw that bear out against Arizona. Another factor is the mobile quarterback, as Matt Scott had 100 yards rushing against Arizona, and Marcus Mariota adds a running element that Darron Thomas didn't provide. However, Oregon has suffered major injuries on the offensive line (Carson York, Mana Grieg), and also have guys like Ryan Clanton and Kyle Long battling injuries.
Last season, Oregon's offensive line was unable to consistently win the line of scrimmage, and it allowed USC to roll out to a big lead that they held on to. This year's Trojan line doesn't have the experience, or the depth, that made such a difference last season, and the few adequate rushing teams they have played have made them pay. The Ducks' offensive line doesn't have to be outstanding, they need to be merely adequate and the Ducks offense should be able to put up plenty of points.