Behind the numbers of Northwestern's outstanding defense

In each of the past two weeks, we've taken a look at just how bad Northwestern's offense has been through the lens of the outstanding S&P ratings from Football Outsiders. But this week, after a tremendous defensive performance, it's time to look at just how good Northwestern's defense has been, since the unit apparently still has some doubters, even after a 29-6 trouncing of Penn State.

I understand the skepticism surrounding the Wildcats' defense, I really do. The unit wouldn't stand out without access to points per play data, and it has struggled in recent years. Plus, NU hasn't faced a truly outstanding offense yet (though it probably won't face any this year). However, this defense is good, and that's proven by just about every facet of this week's S&P ratings.

I'd encourage everyone to go to Football Outsiders to check out what each of these means in more detail, but I'll do my best to show what this defense is good at and why it's so much better than in past years. The most noticeable improvements have come in the run defense and on standard downs.

The improvement of the run defense is the most impressive and perhaps the most surprising. Despite losing defensive tackle Sean McEvilly for the year, the interior defensive line has done an extremely good job of stopping the run — far better than any NU unit in the past four years.

While defensive tackles CJ Robbins and Greg Kuhar have been very good, the Wildcats' defensive ends have shown an ability to assist in the run defense, with Dean Lowry even moving inside at times when depth wears thing. While depth is a concern, and while Wisconsin's running game will make these raw numbers look a bit worse next week, this run defense has proven that it has the potential to be far more effective than it has been in previous years.

Moreover, the improvement on standard downs — all first downs, anything less than 2nd-and-8 and anything less then 3rd-or-4th-and-five — is even more encouraging. While the Wildcats clamped down on big plays last year (and have again this year), this iteration of the defense is doing a much better job at limiting the efficiency and overall play-to-play success of its opponents.

That's a remarkable four-year turnaround, and it's due to a mixture of personnel and coaching improvements. As the recruiting rankings have reflected, Northwestern has improved its personnel tremendously on defense over the past few years, and as safety Ibraheim Campbell noted, there's "a new level of athlete" on the field for the Wildcats this season. NU has tended to have a better offense than defense, because you can scheme more offensively to make up for talent deficiencies than you can defensively. But now, the talent is starting to arrive.

This new crop of NU defenders is stronger and more athletic, and that's especially evident in the front seven, where Ifeadi Odenigbo, Xavier Washington, Anthony Walker, Dean Lowry, CJ Robbins and Greg Kuhar have shown how bright the future is. With this surplus of talent, defensive coordinator Mike Hankwitz can be more aggressive, and the pressure he dialed up on Christian Hackenberg this weekend may have very well won the Wildcats the game.

There are still areas for this defense to improve (most notably on passing downs), but overall, this is the best defense Pat Fitzgerald has had in quite awhile, and it could be his best ever. Given the uptick in recruiting and the young talent already wreaking havoc against opposing offenses, maybe this new-and-improved defense is here to stay.