While this game didn't lack for some fascinating things to talk (or grumble) about on both sides of the ball, I wanted to give the defense—and particularly coordinator Don Brown—their due for the rush package last Saturday. By the final drive, Iowa was flat-out not blocking fifth rushers, they were so discombobulated by what Michigan was doing. Joel Klatt explains:

How did we get here? Why was it working so well against Iowa in particular? I think I have to start with what each team wants to do.

Don's Defense

The basic precept of the 4-2-5 Cover 1 defense that Don Brown brought from Boston College is you want to be able to play man outside and cover extra gaps with your linemen in order to free up the linebackers for havoc.

As the name suggests, there are two of these LBs to spare, taking into account that together they have to cover (or get to) the running back. Often one linebacker is sent on a blitz. The other is used to guess where the ball is going in reaction to the pressure, to provide extra coverage there. If one is sent on a blitz that's one pass read that's going to be open, but Brown’s philosophy is if you can cover the first two reads by playing tight off the snap and dropping an LB into the 2nd read, there won't be time for a third.

Ferentz's Offense vs Cover 1

Iowa prefers safe underneath passing to their surehanded receivers, either underneath soft coverage or to their slot receiver running through the linebacker level looking for holes. They keep this open by threatening the seam with their tight end, and using their deep threat receiver to keep the safety occupied.

In practice it's a lot of crossing routes and dink & dunk, with the defense's overreaction to this opening up big plays to the tight end or deep receiver. It works well with Mesh (just run the #1 receiver across the slot) as a one-two combo. Mesh is to passing what inside zone is to running: it works against everything and it's run by everyone. It's how you play off mesh that determines your identity, and this underneath passing game is Iowa's.

This year the tight end hasn't been much of a threat so they're having him mostly just block the SAM (or Viper in our case) out of the play. Is it OPI? Yeah, probably, but this is the Big Ten.

[After the jump, let them fight]

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Round 1: Stunt Doubles

Brown's plan to deal with the Ferentz Play was to generate pressure as fast as he possibly could, which in theory should prevent Stanley from setting and making the accurate timing throws this requires. That starts with playing the cornerbacks down—that's a Michigan standard. No free yards underneath. But Brown wants to still get away with covering the slot receiver's inside routes with a safety lined up with outside leverage, since that keeps the middle linebackers in reserve to play our games.

Iowa's first 3rd and "long" (four) was Michigan's first opportunity to bring out the rush package. It's a sort of 3-3-5, but the DL are Paye (anchor), Hutchinson (nose), and Uche (end), a very light personnel group. Both linebackers are down to pressure the B gaps, with Hutchinson 90% lined up over the center just a bit shaded to the field side A gap, and both Paye and Uche offset from the tackles. The "linebackers" on this play are McGrone and Brad Hawkins. They'll send McGrone and keep Hawkins to patrol the spot the slot receiver's drag route ought to be heading.

The attack turns Glasgow into a DT. Paye and McGrone flipped gaps. Hutchinson dove to the boundary side A gap with Glasgow looping to come up the center's other side. Brad Hawkins is down to cover the B gap Glasgow was over, but in a linebacker role, relating to the running back but otherwise available to drop into any crossing routes. The replay angle shows what this looked like to the quarterback. That's the key because I want you to look at this pre-snap and think where you think the pressure's coming from:

One of the things they drill into quarterbacks is throw in the direction of the blitz. Makes sense, right? The defense is using up their guys for that side, so the coverage behind the blitzers ought to be lighter. The pre-snap motion suggested man coverage with Metellus and Dax Hill flipping. That's what Iowa wants: the TE's release should be physical and get in between Metellus and the inside-releasing crossing receiver. The down LBs suggested some sort of blitz. It was therefore a fair assumption that Hawkins was coming, or at least would be taken up with the running back.

Iowa's still fine as long as the protection survives. The real key here is Glasgow's stunt. He gave RG #61 a little shimmy to get that guy to step outside just as Glasgow dodges inside two gaps. Iowa's RB uses himself up in the first gap, which has Hutchinson already bottling it up and a sorta surprised center holding a titch. With the protection expecting attackers on the center's right, nobody can peel back to get Glasgow, who's about to get a free hit. That forces the throw to the crosser who's supposed to be bracketed by Hawkins and Metellus.

Iowa Responds

So, okay, the Hawkeyes have seen this before and they adjust. Next long down they get, they run the same thing with the same motion but flip the jobs of the tight end and the slot receiver. Now there's no zone protector ratting around under there, just a quick slant underneath the safety.

Brown is running the same thing except with base 4-2-5 personnel. This time Uche is the blitzer, and McGrone is supposed to back into the spot the crosser will get to. However Michigan has guessed wrong: the crosser is the TE and he's just dragging everyone away from the top route, which is now just a quick slant because they have to react before Metellus can make up the ground he gives up by aligning in a "No Fades!" alignment.

Watch the replay here and see what happened with that protection though.

It's a different stunt this time. Hutchinson blows right into the center, carrying the RG with him. Kemp at first looks like he's going backside A-gap, and McGrone is stepping that way. Again the RB uses himself up to the side with more threats, just as Kemp reverses course and comes around that frontside B gap.

Iowa's won this round, but Michigan's winning the war: Iowa's using high school protections, and their interior OL aren't good at adjusting them on the fly to anything complicated. I shouldn't pick on a 280-pound redshirt freshman center, but Brown sure as hell will.

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Round 2: Feint and Jab

Iowa's setting their protections based on pre-snap reads of which side has more threats. So Michigan returns with one of that thing your uncle does where he's like "See this fist? See it? You know what this is? It's a decoy!" [other shoulder gets punched].

The setup, right up until the snap, feels like Michigan's bringing pressure from the field side. Hawkins over the tight end suggests Khaleke Hudson is free to do something. The pre-snap read, in Iowa's simple reads, is thus to the tight end's deep cross between those safeties. Basically it's the same read they've been making in the short game, just run 15 yards downfield. Clear everybody out and run an athlete across the line until he finds space.

They adjust well enough, with the extra protection from having their starting running back on the field instead of a slot receiver picking up the boundary side blitz from McGrone, though at the expense of an entire receiver on 3rd and forever. Meanwhile Uche and Glasgow, the two guys they were all worried about doing something cool on whatever stunt, are dropping into deep coverage zones. In other words, Michigan is using both "linebackers" in coverage, rushing four. Iowa's got both gloves over their face and we're not even throwing a punch.

Of course this four-man DL didn't take expected lanes, and that means the body blow is coming. Aidan Hutchinson is already forcing a 75% Alaric Jackson to use up one of his get-out-an-extremely-obvious-hold-right-in-front-of-two-refs-free cards, and Kwity Paye is looping around the unsuspecting right side of the line, where only Tristan Wirfs has the mind to engage, and even he can't prevent Paye from setting an edge and forcing a throw. Iowa's guards block nobody.

It wasn't the last time they ran it either. Except the next time Don Brown had Khaleke come down like he was the blitzer instead of McGrone. When Khaleke backed into coverage, nobody even saw McGrone.

Replay so you can see what Stanley saw:

Iowa Responds

Next quarter there's a crucial 3rd and 3, Iowa's rushing total is already in potential Rutger range, and crossing routes have been converting at an annoying clip. Our fighters step back in the ring, and this time Iowa's got a new hook: a curl / flat read on the backside that should break either the receiver open or get the running back free in the flat.

Stanley's third read is actually open but what he's looking at is the curl / flat on the boundary side. Pre-snap he sees a loaded weakside, sees Hudson come down as well, and assumes the right side is going to have all the coverage. He's not quite right. Let's check in on how the linebackers are deployed this time:

Khaleke Hudson is blitzing, Cam McGrone is replacing him in zone, with running back responsibility if it comes to that. It comes to it, and McGrone makes the right choice.

The left is indeed loaded, with blitzers coming in all three gaps. Iowa has gone to maximum simplification on their blocking scheme, with everybody taking the guy over him, and letting the QB throw over any blitzer who manages to come from outside of it. Stanley sees Hudson coming in hot, and is already of a mind to throw it to his running back, when he sees Hudson replaced by McGrone. Hurried or fearful of getting his RB blown up, Stanley wings it.

This play isn't about subterfuge so much as attacking as quickly as possible to make it hard to read and throw to the open guy. Khaleke Hudson is put in a position to do what he does so well, which is accelerate into the backfield so fast that the quarterback can't get to a third read. Here, at least, our unit is living up to the slogan—solve your problems with aggression. McGrone as the lone linebacker really ought to be caught between the RB swing and the curl that Dax Hill shouldn't be able to get to alone. But because of the speed with which Khaleke arrived in the backfield, there is no third read. Stanley only has his first read, and McGrone correctly read/guessed which it would be.

We even get to see what Michigan was trying to do with Jordan Glasgow as a tackle against Wisconsin. There he was just mauled. Here he's so much more explosive than the guard over him that Glasgow can dodge him and get into the surprised center, driving that guy back a bit. Two Iowa players are used up on Jordan Glasgow: defensive tackle.

But we're not done here.

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Round 3: Your Best Punch

So that was a nasty trick, but now Iowa's seen Michigan's play for a 4-wide conversion of three yards. The concept on the field side was there: use the innermost receiver to slam into Hawkins and remove him while you run a route underneath. If that's Brad Hawkins's guy, he's getting interfered with and can't do anything about it. If it's Dax Hill's guy, he's got a lot of traffic to cross. The slot receiver is allowed to stop or keep going until he finds a spot to sit.

So Iowa goes back to the base play. The running back is no longer in a route; he's going to stay back and block whatever Don Brown is bringing this time. That would be McGrone in the B gap, with Hudson drifting into the spot the curl attacks.

Meanwhile Michigan's flipped the play from the same look. With the TE in a pattern, there are three pass rushers—Glasgow, McGrone, and Uche, for two blockers by trade—the right guard and right tackle. Fortunately for Iowa, this time they've left in the running back as an extra blocker. But once again, Michigan has replaced the spot that McGrone came from with Hudson. Once the first read and throwing to the spot Michigan blitzed from are gone, Stanley has to hope his protection can hold up for one more read. That would be the slot receiver converting his route into the drag, still a damn fine play if McGrone can't get a chip on him.

Except here Michigan gets to bring out their secret weapon: more talent than Iowa.

Up until now the athletes were evenly matched. Dax Hill changes the math. He's several steps behind when the slot receiver crosses McGrone. He's there to tip when the ball comes. Like dang.

Iowa Responds

The Hawkeyes have one more trick to pull out with this series. If the last one failed because of talent, this one fell to luck. They try a screen out the backside, and it just so happens Michigan is in their trap coverage that play.

At this point I hope I don't have to draw it up. Michigan's doing the thing they were doing in "Round 2" where they rush four (but it's hard to guess which) while dropping both LBs from the side that looks like it's going to get all the pressure. Behind this they're playing Don Brown's trap coverage, which draws Lavert Hill right into the screen this was supposed to set up. I mean: poor Iowa. Nate Stanley has taken to calling out the protections himself at this point (you can see him doing all the pointing whereas his center was doing it earlier), and he gets this one correct. And it just happens to be when Michigan's not even turning their corner's back to the play.

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Round 4: Knockout Blows

If you like boxing because of the vicious shots to the face, they often don't come until the point when the fight's nearly over. Eventually the accumulated body blows break something in one of the combatants, his opponent leans on him for awhile, and then the finale is a rush of the doomed man swinging for broke, and the soon-to-be champ landing vicious head shots. Or in this case, various Michigan defenders putting Nate Stanley-shaped holes into the big one Yost dug.

Michigan has fallen into a rhythm with this flipping the pressure and replacing. Iowa runs the cousin of the Ferentz, the double-mesh, and Michigan is dropping guys into it like they have the signs.

They don't. It's just the same thing we saw against the screen a second ago: four-man pressure with Dwumfour faking out the RG so bad that guy can get nothing on McGrone when Dwumfour ducks into the other lane. Meanwhile the side that looked like it was going to be pressured dropped Glasgow right into the mesh. There's nowhere else to go but the RB outlet pass that would need a broken tackle to have any chance at the 1st, and Stanley has to do it with McGrone in his gut.

Needing to convert long Ferentz puts the three receivers in a bunch and tries to have them recreate the same combination 15 yards downfield. But three of his linemen use themselves up on Carlo Kemp and Cam McGrone jukes the running back left back there in the hope that 6-on-4 will do better than 5-on-4.

Finally Iowa gives up on the idea of a running back altogether. This is what Florida did to Brown last year: if you go five-wide, and Brown still wants to rush five, he has no extra linebacker anymore because every guy is on someone. The first one works—this is the slant version they responded with in Round 1, and here it beats Khaleke.

The upshot: if your five-man line can't protect the quarterback long enough for the five-man receiving team to get open, it's light's out. Now all the four-man pressures can come out, and Michigan gets their coverage linebacker back. The first time Iowa is saved by a false start.

The next time they're not.

Two linebackers. One to create pressure, one to pop up where a guy under pressure might throw it. Mix up who's rushing and where, have it executed as well as Kemp and Glasgow had it down, add a dash of elite speed from Khaleke Hudson, Cam McGrone, and Dax Hill, and that's how you box.