Previously: Iowa Offense
Because I was just reminded that this picture exists, and it sums up the feelings about Michigan/Iowa for anyone without a serious rooting interest.
Now that Michigan is suddenly basing their running game on the inside zone with the overhanging threat of a bubble screen, my choice to break down Iowa's game against Northwestern has become oddly relevant to Saturday's matchup against the Hawkeye defense. In this one, the Wildcats were able to move the ball consistently on the ground (13 first downs rushing, 5.1 ypc with sacks removed) and struggled with any passes that weren't quick, short throws (six first downs, mostly on underneath throws, 4.1 ypa when accounting for sacks).
The Hawkeyes did what they do best: play bend-but-don't-break defense that keeps big plays to a minimum, and they got just enough from their offense to pull out a 17-10 overtime win. On to the breakdown...
Base Set? 4-3 over, though the Hawkeyes spent much of this game with five DBs on the field, lifting SLB Anthony Hitchens, to counter Northwestern's spread attack.
Man or zone coverage? Almost exclusively zone, with the notable exception of playing man the first few times Northwestern showed a 3x1 trips set. The Wildcats would motion the lone back outside of the three receivers. The man coverage worked well when Kain Colter targeted the man covered by outstanding cornerback B.J. Lowery:
There was significant confusion, however, when Northwestern went to the other side of the field, as the Hawkeyes flat-out failed to guard the slant thanks to some nice route design and poor recognition by freshman CB Desmond King (#14):
After this happened a couple times for first downs, Iowa adjusted to playing their usual Cover 2 against this look and Northwestern stopped utilizing it after a couple incompletions.
Pressure: GERG or Greg? Extremely GERG-ian. Iowa rushed more than four players on a passing down once, by my count, and often brought just three pass-rushers from a nebulous front while using MIKE James Morris as a spy with the option of coming on a delayed blitz. This specific wrinkle will be covered further in the play breakdown section.
When Iowa wasn't utilizing that particular look, they tended to rush four linemen with an obvious emphasis on maintaining their lane over getting to the quarterback against a mobile guy like Colter. The Hawkeyes had six sacks on the game; they netted just nine lost yards for Northwestern, as five of the six were coverage sacks in which Colter moved up in the pocket and tried to escape, only to get buried right around the LOS.
Dangerman: I was going to give this to WLB Anthony Hitchens, who tallied nine tackles (2 TFL), a sack, and a forced fumble while making several very impactful hits, including one that blew up a screen in Ryan-esque fashion, but then he bit hard on a play-action and subsequently gave up a wide-open touchdown in a critical situation.
Since I was torn between these two anyway, I'm going with Lowery, who recorded the PBU above and did an excellent job of tackling on the perimeter—that's very critical given Iowa's tendency to play soft zone coverage and rely on their corners to not leak yardage after short completions. He's far and away the team leader in pass breakups with 13 and also tops the Hawkeyes in forced fumbles with three. Northwestern didn't test him a whole lot—they only threw 14 passes all game and mostly stayed away from him—but when they did he made them pay, either by knocking the ball down or tackling receivers for minimal gains.
OVERVIEW
It's hard to emphasize enough how vanilla this Iowa defense is; they're going to sit back in zone coverage and dare opponents to beat them over the top for big plays. Northwestern only took a couple deep shots and their one long pass completion, a wheel route to H-back Dan Vitale, came on an inch-perfect throw that barely eluded Lowery's fingertips—and that still required Vitale to make a difficult over-the-shoulder catch on the run. Michigan has skill position players better suited to test Iowa deep. That doesn't mean it's going to be easy.
Starting up front, I thought the defensive line was the weak point of this Iowa defense. Though partly by design, they never got much push in the pass rush, nor did they hold up particularly well against the run—Iowa's linebackers rack up a ton of tackles in part because they're almost always the first guys to get decent contact on running backs. Out of curiosity, I tracked Northwestern's success on inside zone runs, and what I found supported this: the Wildcats amassed 69 yards on 14 inside zone runs (4.9 ypc) and gained at least three yards on all but one of them.
Of course, that also speaks to the sure tackling of their linebackers and safeties; the longest of those runs netted seven yards, and a three-yard gain ended with a lost fumble after a huge hit by Hitchens. The trio of Hitchens, Morris, and Kirksey at linebacker impressed; they rarely got out of their zones in pass coverage, while any run that got to them stopped upon contact. The best gains Northwestern got on the ground came on Kolter scrambles—usually up the middle as the DTs couldn't disengage; the DEs contained well—or quick-hitting runs to the edge, which included two speed sweeps by a motioning Vitale.
"A lot faster than you would think" is still not as fast as James White.
Safeties Tanner Miller and John Lowdermilk both did very well in run support and weren't tested at all in coverage; they flow downhill quickly and don't miss many tackles. The BTN play-by-play guy noted that Lowdermilk is "a lot faster than you would think," because he closes quickly and is white.
Lowery is obviously the standout corner; King, the true freshman starter across from him, did an impressive job of tackling for such a young player and didn't make any noticeable mistakes aside from the error in man coverage I pointed out above. Northwestern had inconsistent success getting first downs on hitches and crossing routes over the middle against Iowa's zone coverage; when those routes weren't open, Kolter was running around and usually taking a sack.
Michigan is going to have to find a way to consistently churn out yards in the running game, get receivers open underneath, and avoid turnovers at all costs; the difference between a solid offensive output and a poor one is going to come down to a few big plays going in one direction or the other, especially since the Wolverines haven't shown an ability to sustain drives via short-to-medium gains over the course of a full game. I don't think Iowa's defense is as good as the raw numbers suggest (#9 nationally in yardage allowed); their FEI rating of #46 passes the sanity test for me—they're decent, not great, and like Michigan under Mattison are able to cover up for a lack of playmakers on the line by executing basic schemes and getting solid, mistake-free play from the back seven.
PLAY BREAKDOWN
Iowa showed this nebulous front on several third-and-longs in which they'd have just three linemen on the field, nobody would get set, and the front 4-6 players (including linebackers) would move around a lot before the snap:
The Hawkeyes almost always dropped eight men into coverage out of this formation; sometimes Morris would come on a delayed blitz, sometimes he'd rush right away, and in one instance they brought five rushers—on that play, Colter escaped the pocket and picked up a first down. That caused Iowa to mostly abandon this tactic in the latter stages of the game; early on, however, it got them a sack when Morris blitzed late and nobody on the Northwestern line picked him up:
While Northwestern didn't have too much trouble picking these rushes up otherwise, the concern here is that Michigan's offensive line ... well, you've seen enough missed assignments and blitz pickups to know the concern here. I wouldn't be surprised to see Iowa utilize this look often early in the game until the Wolverines prove that they can consistently identify and pick up rushers when they're moving around that much before the snap.