No Fly Zone- getting WRs right where you want them

You hear a lot about how MSU 'puts its corners on islands' and 'dares you to throw at them'. This is the language of a high-risk, high-reward strategy where the first misstep by either side leads to catastrophe. But in reality, the strategy hasn't lead to astronomically high interception rates or many long touchdown passes conceded. What it has done is force lots and lots and lots of incomplete passes, a relatively boring, but undeniably successful outcome. What struck me last year was how few easy throws opposing QBs had, and how many insanely difficult throws they were asked to make. Was there something schematic outside of just the talent of the MSU defenders that was forcing this? I think so, and it seems to be an over-arching pass defense centered around a simple strategy .

Protect the middle of the field

When you watch MSU's pass defense it's extremely common to see defenders try to force receivers out of the middle of the field, similar to a basketball team walling off the paint with defenders. The middle linebacker will attack the slot receiver or tight end and keep him from crossing the hash-mark. The cornerback will shade or attack the inside shoulder of the outside receivers to encourage them to release towards the sideline.

Why force everything outside? Simple math and simple physics.

The middle of the field is a shorter throw.

Because of the existence of hash-marks, there is a ~6 yard horizontal space in the center of the field out of which every play starts. From the middle of the field, you can get about 3 yards closer to either side of the field before the snap, but no more. And because the pre-eminent football strategy is to create a static pocket around your QB (whereas roll-outs and moving pockets are used as more of a change-up) it's likely that the majority of attempts by the QB will come from in or near this 6 yard horizontal space.

This means you have a clear advantage as a defense in keeping receivers out of the middle of the field.

Here's a visualization of why:

Those lines are based off of pixels instead of hard measurements (we'll look at those in a sec) but you can see that this throw to the sideline is about 33% longer than a throw to the middle of the field, with throws to the hash-marks, numbers, or in-between also being longer throws.

The numbers based off the actual yardage specifications show that on a 25 yard throw down-field, the pocket QB needs to throw the ball about a full 10 yards farther than on a throw to midfield.

But these are basic, basic, math concepts. We know this stuff.

The football logic is that forcing outside throws both requires the quarterback to make a longer throw which should either be less accurate, or, potentially impossible if the QB lacks the necessary arm-strength, and also gives your defensive backs and linebackers more time to find the ball, react, and break it up or intercept it. You're getting two birds stoned at once.

But wait, what if a team starts moving around the throwing point of their QB away from the middle of the field like you show in that diagram. Wouldn't a steady diet of roll-outs hurt you if you're forcing routes to the outside?

I don't think so, and I think that might even be a better strategical outcome. Two reasons:

1. the sideline is an extra defender for you.

Receivers and quarterbacks obviously can't cross over the sidelines. This means, unlike when your QB or receiver is in the middle of the field, he has to be wary of this new restriction on his and his target's movement. Every step towards the sideline shrinks options. The field is essentially cut in half because...

2. It's a bad idea to throw across your body

This is axiomatic, but the physics back it up. You can try this right now. Pick up a football, or a pencil, or your computer (note: don't use your computer) and throw it to your left with your right hand from a stationary position and then try throw it to your left from the same spot while you're running towards your right. Simply due to momentum and the mechanics of your body, the act of throwing on the run is going to likely send your throw all to hell, as your arm has to fight against the rest of your torso to get the object airborne properly. Because a quarterback will almost always roll-out to the side of his throwing hand (because otherwise he either has to run backwards to keep his lead foot pointed down-field, or otherwise has to spin around 180 degrees at some point to achieve the same), any passes to the opposite side of the field, or even the middle of the field are now suddenly fraught with danger.

So if that's the reasoning, let's see some of this theory in action.

Here's a GIF that shows a bunch of interlocking concepts happening in the span of a handful of seconds:

Here you see two types of defensive influence:

Manipulating through contact

Max Bullough is going to put his hands on this slot receiver and try to keep him from getting to the hash-mark. He slides from the middle of the defense, engages with his arms onto the inside shoulder of the receiver and prevents him from quickly getting near the hash-mark and then passes him off to the waiting safety who is also positioned to deny him the middle of the field. This is a hard reroute.

Manipulating through positioning

Dennard is going to get his receiver to where the defense wants him much more subtlety.

I want to note a handful of things here:

1. Attacking footwork

Watch Dennard's very first step. It's towards, not away from, the receiver. He's not going to reach out and bump the receiver off the line, but his first step with his left foot attacks, again, the inside shoulder of the receiver, and though I think he's heading outside on this route regardless, this jab step effectively plants Dennard square in the path of any possible slant routes towards the inside of the field.

2. Shuffle, very little to no back-pedal

The 5 to 10 yard back-pedal, as I understand it, is utilized to allow defenders to read their receivers while staying with them down-field. If you're defending against someone, in any situation, you want to be able to see them fully so you can respond to their movements. A back-pedal allows you to mirror them and if they turn outside, you open your hips and go outside, and if they turn inside you open your hips and go inside. Dennard (and Bullough) instead both commit and turn to face the sideline, then slide and shuffle until the receiver gets horizontal with them at which point they turn and run down-field with them.

I think the avoidance of the backpedal is another aggressive move that doesn't require you to actually touch the receiver. Yes, if you are turned horizontally towards the sideline and the receiver beats you back to the middle of the field, you're in trouble, but because your slide keeps you horizontal, if you've gotten inside the receiver off the line, your body is now a wall they have to fight through and you are going to get the first shot at the football, not them. If you do the early stuff right, fighting through you should be very tough and time-consuming for the receiver.

I think there are two other advantages to avoiding a back-pedal:

A. It lets your players play faster.

The immediate slide or shuffle technique makes it easier for your players to stick with receivers, both because their stride can be longer, and because lateral movement is easier than it is in a backpedal. This is in part because...

B. back-pedaling is unnatural.

It feels weird, it's something that the average person will only engage in out of necessity or panic. Look at your knees, and your feet. Humans just don't seem built to move straight backwards with any sort of confidence. Which is why you have to drill a specialized 'back-pedal' technique that takes time and effort to hone, whereas anybody can pretty well shuffle if they've played any sports at all.

3. Watch Dennard look back for the ball

He doesn't quickly look back and then turn away, he stares the QB and the ball down for two or three solid beats before figuring out how he's going to keep the receiver from getting it. That look-back is what allows him to then use his hands on the receiver to fight for the ball a second later, something every referee or official acknowledges when the subject of MSU and pass interference comes up. That look back is damn near everything.

4. Finally, as the ball reaches the receiver, look where he is and look where Dennard is, and look where the sideline is.

The receiver is a yard, mayyybe two yards off of the sideline, Dennard is exactly between him and the open field.

This means that the QB has to drop the ball in over Dennard, but not past the sideline, giving him about a yard or two worth of passing window to work with. Oh by the way, did you notice that this is 25 yards down-field from the line of scrimmage? It is a nearly impossible throw for a college quarterback to make, and thus it's no surprise that the pass is too high and falls incomplete. A 35 yard throw from the middle of the field to a tiny window between the CB and the sideline, and by the way, the receiver has to get a foot down in bounds? Advantage: defense.

Here's a couple other examples from the same game showcasing these same discussed concepts:

LB jams inside out and passes to safety. More of a back-pedal and less of a shuffle from Dennard here but concepts of opening his body up toward the sideline, the long look-back, forcing a difficult throw from the QB, and then fighting for the ball/positioning remain. The WR actually gets a step on Dennard and manages to fight his way back to the numbers but can't battle back through him for the ball.

And again, hard reroute on the slot, CB gets outside receiver between him and the sideline, and makes the throw almost impossible to complete.

Conclusion

Of course, no other team tried to attack the deep sidelines quite as hard as Notre Dame did, but perhaps with good reason: they'd already seen that plan fail. However, just because this game featured some of the clearest examples, didn't mean other teams didn't get bogged down into similar troubles. It's no coincidence that many of opponent's longest pass plays came up the middle of the field, or that they found so little success towards the outside of the field. That was part of a concerted Spartan effort to discourage the former and persuade the latter.