It is very much unlike ESPN to exaggerate or talk in absolutes, so I was especially taken back when they starting discussing the 2008 USC team as possibly one of the best defensive teams of all time.
And so I was obviously compelled to pull the numbers. As always, we stress context, context, context. Here are USC's opponents, their scoring and total offense rank nationally (out of 119 teams) and how each performed against TBDOAT:
| Team | Scoring Offense | Total Offense | vs USC |
| Arizona | 16 | 33 | 10 |
| Arizona St | 84 | 100 | 0 |
| Cal | 28 | 49 | 3 |
| Oregon | 7 | 8 | 10 |
| Oregon St | 25 | 26 | 27 |
| Stanford | 55 | 68 | 23 |
| UCLA | 109 | 112 | 7 |
| Washington | 118 | 117 | 0 |
| Washington St | 119 | 119 | 0 |
| Virginia | 115 | 104 | 7 |
| Ohio State | 43 | 78 | 3 |
| Notre Dame | 67 | 65 | 3 |
And Penn State, who is no slouch on defense either:
| Team | Scoring Offense | Total Offense | vs PSU |
| Illinois | 42 | 19 | 24 |
| Indiana | 96 | 72 | 7 |
| Iowa | 34 | 52 | 24 |
| Michigan | 98 | 109 | 17 |
| Michigan St | 56 | 67 | 18 |
| Ohio State | 43 | 78 | 6 |
| Purdue | 67 | 51 | 6 |
| Wisconsin | 48 | 36 | 7 |
| Oregon State | 25 | 26 | 14 |
| Syracuse | 100 | 115 | 13 |
| Temple | 82 | 106 | 3 |
[Remember that Penn State didn't play Minnesota (82/91) or Northwestern (74/62). Also, I was forced to exclude Coastal Carolina as they really can't be compared to D1a programs and don't have a D1a rank.]
And a summary:
| Team | Scoring Avg (Oppt) | Total Avg (Oppt) | Defensive Avg (Score/Total) |
Top 25 Faced (total) | Bottom 25 Faced (total) |
| USC | 65.5 | 73.3 | 7.8 / 206 | 1 | 5 |
| PSU | 63.6 | 66.5 | 12.4 / 264 | 1 | 3 |
Bullets? Sure.
- Of the 20 worst total offenses in D1a, these two teams played 8 of them. That's going to skew things a little bit.
- USC has three shutouts this season, all of them are against teams ranked in the bottom 20.
- When you look at the average rank of opponents it looks like these teams played a similar slate of talent. The somewhat subtle difference is that USC played more absolutely terrible teams, but then some decent ones. PSU's opponents are less extreme.
So who's defense is the best of all time evah? I hate even asking that questing because it doesn't make any sense and can't be determined anyway, but based on the level of competition each played (offensively, I mean), I think it is safe to say that neither one is completely out of this world. Both have performed very well, but both have also faced a relatively weak slate; an average around 65 is nothing to print billboards about. Each has also had a couple of breakdowns.
So who's defense is better? We had to go here, didn't we? Well, again, it impossible to say for sure, but there is this to consider:
USC's scoring and total averages are better, and the level of competition is somewhat similar. However, I quickly went back through the box scores and came up with this non-scientific stat: each team has blown out a lot of their opponents and weren't playing their first team defenses the entire game. I estimate (and am relatively confident in these numbers) that USC has given up 9 garbage points, Penn State 21. That brings the average numbers a little closer together.
Again, I don't think there is anything here that you can use to distinguish these teams.
So what does it all mean? Well, I think the game hinges on which offense is able to keep themselves together. As is usually the case when two great defenses face off: turnovers are a very important stat. It's going to be difficult to overcome a negative turnover margin when you probably aren't going to be given very many chances.