Let's get historical.

Way back in 1969, a year in college football Michigan fans probably better remember than most, Ohio State had a really fearsome defense. A big ingredient in their winning formula was safety Jack Tatum, who was 5-foot-10, 200 pounds, and hit like a modern safety in an era in which Dan Dierdorf was the only Michigan offensive lineman who could tip the scale past 220.

The "upset of the century" when Bo Schembechler ruined Woody Hayes' perfect season, was achieved by Michigan running fullback dive and lead into the boundary repeatedly. The boundary was where Tatum wasn't, you see. So Michigan fired off quarterback runs, options, and dives to batter down doors that didn't have Tatum on the other side.

Good strategy, although it essentially forced Michigan to play in a box for the entire game. Fortunately they had a good plan on defense as well which didn't demand an explosive approach to moving the football.

The 2021 Michigan Wolverines have a similar formula as the 1969 Buckeyes' defense. It's extremely difficult to attack the wide side of the field against Michigan because of the way Mike MacDonald deploys his two best players, Aidan Hutchinson and Daxton Hill.

[Hit the Jump for how MacDonald is deploying these two chess pieces]

If you hadn't noticed, Hutchinson and Hill typically both play to the wide side of the field as the strong outside linebacker and nickel, respectively. No matter if Michigan is playing an odd or even front defense, Hutchinson's task in the run game is to set edges and box in runs so they don't get wide of him to the field.

Meanwhile Hill lines up on slot receivers to the field and usually matches them in something close to man coverage whether it's a two-high or single high defense.

Their play creates a virtuous cycle as Hutchinson's run support allows Hill to focus on coverage on the perimeter while better coverage from Hill creates time for Hutch to work his way to the quarterback in the pass-rush.

Hutchinson has six tackles for loss and 4.5 sacks through just five games while Hill is second on the team in tackles and has a pick and four pass break-ups. As good as they are, those numbers only scratch the surface of how devastating the combination is for the Michigan defense. A considerable part of college offensive strategy, particularly for spread offenses, involves attacking the wide open spaces to the field. Whether by running the ball into them with a fast runner or throwing to an inside receiver aligned on the opposite hash of the ball.

If you can't get the ball outside of the box because of a edge-setter or you can't hit any open throws to your slot receiver because of man coverage on the slot, virtually all of the pathways to easy offense for college teams is erased.

In a related story, Michigan is giving up only 12.8 ppg and is +5 on turnovers (+1 per game). As you may have noticed, the play of these two men on the wide edge was instrumental in Michigan's first win in Camp Randall in 20 years.

Badgering Wisconsin

There was a brief moment when Wisconsin was going at the strength of the Michigan defense and coming out ahead. Graham Mertz hit a pair of vertical routes to Chimere Dike (cousin to speedy running back Manticore Gates) going up against Daxton Hill. 

pic.twitter.com/obIvK96HUG

— Asst to the Minister of Culture (@Ian_A_Boyd) October 5, 2021

For good reason, Hill doesn't typically get safety help outside of the hash marks in coverage. The safeties' attention is better spent elsewhere, Hill is almost an island corner in this system. You'll also notice Wisconsin held up here against Hutchinson working off the edge. They can barely hold off Hutch on either throw and Hill is blanketed over Dike on both throws and only beaten by great placement.

Still, they landed the shots and the score was 13-10 Michigan coming back after the half. Then, the matchups turned quite dramatically.

pic.twitter.com/kqZIVfqihw

— Asst to the Minister of Culture (@Ian_A_Boyd) October 5, 2021

First the Badgers try to run the ball to the field from 11 personnel with an outside zone scheme. It's going pretty well, save for the part where tight end Jake Ferguson has to deal with Hutchinson boxing in the play from the edge. This goes poorly.

Hutchinson first resets the line of scrimmage in the backfield and eliminates what otherwise appears to be a good angle to the perimeter, then manages to dive and trip the running back before he can find a crease behind the line. Hutchinson ends up on the ground with the tight on top of him, almost obscuring what a beating this was for the Badgers.

It sets up 3rd-and-9 for Wisconsin, where MacDonald gets nasty.

Rather than taking their chances further with Hill, Wisconsin is aiming for the boundary where they have motioned Ferguson and ultimately have him matched up on an outside linebacker. Let's draw it up for simplicity.

The reason Michigan loves to line up their inside linebackers ("M" and "W") here on the line of scrimmage on blitz downs is to confuse the protection schemes. Wisconsin has to answer questions like, "do we treat these guys as down linemen or linebackers?" How they identify them determines who is primarily responsible for blocking them among the linemen. running back, and quarterback (the quarterback "blocks" blitzers by throwing hot routes).

Since they do tend to drop back in coverage a fair bit, as the Mike linebacker did here, it makes sense to identify them as linebackers and not down linemen. They do so, and when the running back sees the Will charging into an A-gap, he heads there to pick him up while the offensive linemen focus on the defensive linemen.

They clearly didn't expect Daxton Hill to blitz.

It's perfectly disguised. In fact, it's not disguised, he waits until the snap to leave the hash mark and takes the long but ultimately clear path into the backfield. The guard looks to help on the nose tackle and ultimately doesn't block anyone, the running back picks up the linebacker (sort of), the tackle is setting to stop Hutch from taking the edge, and there's no one for Hill.

Responsibility for Hill in this protection is ultimately on Mertz, who probably thought he was dealing with him by throwing it somewhere else. Again, Hill waiting until the snap and for Mertz to be looking elsewhere before blitzing was essential to the success of the pressure. Had Mertz seen the blitz perhaps he could have hit the H receiver hot on the hash but there was some risk there as well with the free safety dropping down on him. At the very least he wouldn't have been popped so hard.

What ultimately matters is Graham Mertz was left in a crumpled heap on the ground after the hit, perhaps with a cracked rib although Wisconsin has been coy about the exact nature of the injury. He did not return.

Executing a pro-style, spread passing attack of the sort Wisconsin has attempted to move toward with Mertz is very difficult. Not only does your receiver need to be able to handle man coverage from time to time from a future NFL athlete like Hill, and not only does your tackle need to be able to keep his blindside clear from big edge rushers like Hutchinson, there also has to be great recognition and chemistry up front between the line, quarterback, and running back on setting protections and picking up blitzers.

It's a high level of skill which everyone has to master, particularly the quarterback who often generals it all at the line, and if you make a mistake big enough it can all come apart.

Mertz's replacement took a sack-strip, lost track of Hill in zone and threw him an interception, and then took a sack from Hutch on another 3rd-and-6. He would have benefitted greatly from an old school Wisconsin gameplan in which he could just hand off repeatedly to a dominant back in the I-formation. It's very hard though to be all in in on the power run game AND dropback passing though.

Meanwhile Michigan invested in their own disaster insurance (or perhaps a new policy) by finding snaps for quarterbacks J.J. McCarthy (threw a 56-yard touchdown) and Alan Bowman (threw a pick).

Denying space to the Big 10

Michigan does move Hutchinson from the field or boundary to help him find good matchups in the pass-rush, but for obvious reasons he mostly lines up to the field where his run defense menaces opposing teams. The same is true for Hill, who will sometimes shadow a top slot to either side of the formation rather than aligning strictly to the field.

Most spread offenses aren't counting on being able to pick up the blitz and execute progression passing against man coverage regularly, they want to use run/pass conflicts to get the ball to fast guys in space. It's much easier to protect a quarterback on play-action or an RPO, and if you hit a crease with a fast back or a speedy slot or push the ball down the field on a post route you can score quickly and eliminate the need for repeated, precise execution.

Who wants to have to nail all their blocking assignments and run the all for even a strong 5-7 yards down the field? Even worse, nailing the protections, progressions, and timing on throwing dropback routes down the field? Both are exceptional if you can execute them consistently, but most teams cannot.

Well it's very difficult to accomplish those easier paths to offense against this Michigan defense because of these two men. So opponents are left to do things the hard way.

The upcoming slate includes a road trip to Nebraska, who's a marginally competent spread offense with a young offensive line, a woeful Northwestern team, and then the meat of the schedule when they go at Michigan State, face Indiana, at Penn State, Maryland, and then play the other team.

These teams are mostly spread units now. The best ones have dangerous outside receivers whom Hill will not be covering as a nickel, but if Michigan can shade safety help over guys like Jayden Reed and Jahan Dotson he'll still have major value. Mostly Michigan will be a puzzle for these teams on a down by down basis when they're working out how to manufacture offense in between the deep shots or figuring out how to move the chains on third down.

Mike MacDonald inherited more talent than most guessed based on Michigan's defensive performances in 2020 and he's shown an NFL mindset for getting his best players in positions where their play can provide force multipliers for the whole unit. There are big tests ahead, but the auspices are very good.