Inside the Play: Northwestern's defense struggles on third downs

Every week, our Ian McCafferty will go back and critically review one or more plays from the past Saturday's game. These are the plays that, more than any others, were crucial in determining the outcome of the game. He'll check the film, and breakdown the how and why of those decisive few seconds.

Welcome in to the first post-loss Inside the Play of the season. We've spent most of the year breaking down the different things that Northwestern has been doing right, but now it's time to look at some plays that went horribly wrong for the Wildcats on Saturday.

One notable aspect of the loss was Northwestern's poor defensive play on third downs. After only allowing conversions on 20 percent of third downs through five games, the defense allowed Michigan to go 7-14 on third downs. A few of these conversions were Northwestern getting outmuscled at the line or Michigan running a perfect route, but there are two that stand out. Joe Kerridge's 34 yard run on third-and-one and A.J. Williams' 13-yard catch. Those are the two plays we'll look at today.

(All Video via BTN)

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Well that certainly got out of hand quickly. Throughout Saturday morning and early afternoon before the game, Michigan fans were confident but wary, knowing that their team was facing one of nation's best defenses. Then the game started.

So what exactly happened to the defense on Saturday? Coming into the game the Wildcats had only allowed 35 points all season. Michigan exceeded that — albeit with two defensive or special teams touchdowns — in a single 60 minutes.

Obviously being down by seven before you even take the field doesn't help, but the biggest problem was that the defense couldn't get off the field. After being one of the nation's top third down defenses through five weeks, Northwestern allowed Michigan to convert 50 percent of their third downs. That's not a recipe for success in any situation.

While Michigan converted seven different third downs, we're going to take a look at the two most egregious ones for the defense: Joe Kerridge's 34-yard run and A.J. Williams' 13-yard catch.

Just two quick observations before we dive in: First, both of these plays occur on third-and-short. So the first problem comes earlier, on first and second downs, on which Michigan had too much success. But then there's the fact that Michigan wasn't just converting on third and short. The Wolverines were breaking bigger plays.

These are both defensive breakdowns that could have been avoided. We'll start with the Kerridge run.

The Breakdown

Pre-snap alignments:

Michigan has the big boys in for this play. They have seven players on the line in tight, and clearly want to run the ball. However, for whatever reason, Northwestern is in its base 4-3 defense. It's not entirely clear why that is, but this is a mistake. The wide receiver out on the edge makes it so Northwestern can't completely pack it in, but that doesn't excuse having so many defensive backs on the field on 3rd-and-1.

Northwestern's lack of reaction to Michigan's personnel and formation makes it to susceptible to a quick-hitter up the middle. The Wildcats might have been able to defend a traditional halfback handoff, but they simply don't have time to hit their gaps when Northwestern goes to Kerridge, who goes in motion right off Rudock's right hip.

This is the field about a second after Jake Rudock executes the handoff to Kerridge, and from an offensive line stand point it is beautiful. All four Northwestern linemen have been absolutely swallowed up and there's a huge hole on the left side of the line. The Wolverines dictate play at the point of attack, and within a split second, Northwestern's linemen are beaten. Here's another angle:

Jaylen Prater actually appears to play this decently. But he's a bit late getting to the hole, and 331-pound Michigan lineman Ben Braden (71) is already there to seal him off. Prater's — and Northwestern's — inability to immediately recognize the intention of the play crippled him — and the Wildcats as a whole.

The final mistake is Matt Harris's:

Harris gets flat-out fooled here. Within two seconds of the snap, Harris is still looking into the backfield, and Kerridge is already past him. The only reason this isn't a touchdown is because Kerridge is a fullback, and Matthew Harris eventually tracks him down.

This play worked because of superior line play from Michigan, and a lack of pre-snap preparation on Northwestern's part. But it was a big play because of a killer fake and a bad read from Harris, the only unblocked player in the vicinity.

Our next play is a similar breakdown, a lack of awareness. But it comes in the passing game:

The Breakdown

Pre-Snap Alignments:

Michigan and Harbaugh really love their two-tight end sets. They've got seven on the line, with two tight ends and two receivers out on the near side. Northwestern is again in its base defense. Godwin Igewbuike comes up to cover the slot receiver while Nick VanHoose stays on the far side, a clear signal that Northwestern will be in zone. And as soon as Rudock snaps the ball, it becomes clear.

Before we address the blown coverage take a look at the perfect pocket that Rudock has on this play. Once again, Michigan's offensive line just destroys Northwestern's linemen and gives Rudock all the time he could want to throw:

As for the coverage, the most important part of a zone defense is staying in your 'zone,' and Anthony Walker fails to do that here. Walker jumps at what he sees in front of him — Michigan tight end Jake Butt — and follows him right into Drew Smith's zone. That leaves the defense looking like this:

That's a simple pitch and catch for any quarterback, especially with the protection Rudock is getting. This is a clear mental mistake from Walker, and frankly it's one that shouldn't be made by a starting middle linebacker in the Big Ten, much less one that has been playing at such a high level.

Takeaways

There are two takeaways here. First, as former Northwestern linebacker Nate Williams noted, the defensive line didn't wreak havoc — in fact, just the opposite — which really made things tough for the rest of the defense. Perhaps a lot of the linebackers' success early in the season was due to the play of those in front of them. With Michigan's offensive line winning the battle up front, the linebackers had trouble, and perhaps were exposed.

On the other hand though, many of Northwestern's mistakes Saturday are fixable, especially those like Walker's on the Williams catch. That fosters hope that the Wildcats' defensive struggles against Michigan will be a one-time occurrence.