It took until week 5 for the Beavers to be tested, and they didn't pass. Oregon State was outcoached and outplayed. The Trojans are the more talented team, but not enough to explain a 25-point loss and 0 points in the 2nd half. Let's look at what went wrong, and what should go right in the future.
Just like last year, Sean Mannion struggled mightily against USC, but it's difficult to put much blame on him. Clearly, 15/32, 132 yards, 2 interceptions and 0 scores isn't pretty. But neither were the receivers, play-calling, or offensive line surrounding him. Two of the more talented receivers on the roster, Victor Bolden and Rahmel Dockery, were both out with injuries, Oregon State never committed to the run game, despite its success, and when USC did bring pressure, it pretty much always got to Mannion, even if it didn't always bring him down. Mannion should, and has, gotten blame for some of his decisions when passing the ball, but often his best chance at a completion was trying to thread a throw through 3 defenders due to how blanketed the receivers and tight ends were all game.
In the end, we know what to expect from Sean Mannion. For the most part, he'll make the right pass and give you a chance to win the game, but, partially due to being a traditional pocket passer, he's rarely able to carry an overmatched team to victory.
More concerning than Sean Mannion's play is Mike Riley's play-calling. On the first drive, Oregon State had runs from Terron Ward and Storm Woods of 8, 15, and 12 yards that helped them get to midfield. From there, the Beavers went pass on first down, fly sweep on 2nd, and pass on 3rd to stall the drive. Same story on their final drive before halftime. Move 25 yards, mostly on the ground, to midfield, then call 5 consecutive passes, culminating in an interception in the end zone. The game ended with Ward and Woods averaging 5.6 yards/carry, yet the Beavers had 35 passing attempts to 21 rushing attempts. The excuse of "having to pass when you're losing" doesn't hold weight in this case, either, as the Beavers were down 11 points for most of the 2nd half and were just as unbalanced then.
In recent years, Mike Riley has become less and less committed to running the ball, despite what he says in pre-season and mid-week press conferences. Last year, it was somewhat defensible. This year, it's an egregious misuse of personnel, and it's hard to believe he's ever going to change his ways.
Contrary to what the Trojans' 35 points seems to say, the Beavers' defense played very well against the Trojans, and proved that they really can compete with the top-tier offenses in the conference. 7 of those points came off a Sean Mannion pick-six, and 14 more came in the 4th quarter after the defense had been on the field for a terribly long time due to offensive incompetence. USC picked up just 42 yards in the first quarter, and the Hail Mary touchdown at the end of the first half was obviously a bit fluky and arguably avoidable had Mike Riley called a timeout. The Beavers' second half time of possession was a whopping 9:25, meaning the defense was on the field for more than two-thirds of the 2nd half, and only broke down late in that stretch.
The defense is legit, and should continue to impress as the season wears on. They'll be slowed, but not stopped, by a couple injuries to the defensive line sustained against the Trojans, and should continue to hold teams down, probably excluding the Ducks.
From here, it will really be interesting to see if the Beavers can break 6 wins. The conference matchups in 2014 have been bizarre to say the least, and we can already see the start of the the infamous Pac-12 circle of death. The Beavers should beat Colorado and Utah, but I don't put a loss to the latter isn't exactly out of the question. Still left on the schedule is the state of Washington, northern California, ASU, and the Civil War. It's tough to have confidence penciling any of those in as wins, as a combination of bad Oregon State play and good opponent play could lead to a Beavers loss in every one of those.
This Oregon State team will go as far as the offense takes them. Unfortunately, Mike Riley seems to think that substituting "offense" with "Sean Mannion" in that sentence is a recipe for success. If he doesn't change that, the offense won't take them very far.