Beaver fans and media have been lamenting the Oregon State defense all year and it is well merited, especially when they have given up over 45 points in two out of three contests, and no one would (or should) claim that the performance against Hawaii was that much better. The defensive unit lost a handful of players, but all the replacements seemed to be in place, and the impact should not have been nearly as high as it has been. Blame can be spread equally across the board, to the coaches, the secondary, and the run defense.
The coaches are somewhat to blame, as expected when any team gives up over 40 points. Mark Banker's scheme is certainly outdated and needs more change, but he has shifted a little bit, starting last year. Banker switched to way more nickel looks, getting an extra defensive back out there to put more speed on the field to help combat the spread, and it saw moderate success last year. This evidence of a properly functioning defense last year with the majority of the same pieces lends the question of what has changed this year and how could that make such an impact? One answer is the lack of contact in practice.
The Beavs did suffer a fair amount of injuries in training camp, but that happens to every team. Last year, there was a lot of media coverage about how Riley was looking for more contact and they practiced with that in mind. Last year's game against Wisconsin was a demonstration of that change, with solid tackling and stopping players in space, wrapping up on first contact and not giving up cheap yards. This year there have been multitudes of missed tackles, poor angles, and other mistakes, that should have been covered in training camp. This is a mental issue, but is unlikely to be corrected, not without some more live hitting in practice.
Another major factor in the poor defense has been the coverage, they did show up at times in the Utah game, but Sean Martin was burned on the first Utah touchdown of the game letting them back into the game. This has been a problem since the Eastern Washington game, where receivers were winning their individual matchups against man coverage, and the defense could not get any stops, even on long yardage downs. This is also a difficult problem to fix, although they have looked better since the first game, but only marginally. Against Utah the Utes had 8.5 yards per pass, but if only looking at the completions, they averaged 14.8 yards per completion and had four completions of 20 yards or more.
The Beaver defense allows short passes, deep passes, all sorts of passes really. The most promising change is the growth of Steven Nelson, who also get beat on a fair basis, but did show up for two quality picks. The secondary can also be found giving large cushions on short yardage downs which opponents have regularly gone to quick slants and got the first down easily. More press coverage would help, but in general the Beavs just have to stick with their man, which they have not done very well so far.
The last major factor is the run defense mainly against read option sorts of plays. Travis Wilson pulled the ball out several times and should have been punished for it, but the edge defender would tend to crash down the line instead of staying with their responsibility. The Beavs need to get back to playing as a unit, even the star players would make this mistake, I spotted DJ Alexander doing it several times.
This is semi-encouraging, as this is exactly what the coaches and players have been talking about. It has been their greatest flaw so far, and was the reason why the Utes absolutely destroyed them on the ground. This is the most fixable problem so far, the coaching will not change, the coverage will get better as Steven Nelson continues to improve (I have less hope for Sean Martin), but this is the most solvable issue. If the Beavs can get back to playing as a unit, the defense can still recover, the athleticism is still there, but the mental aspect has not been. There is still hope for the defense, but the changes need to happen soon.