H4: Forty-Three Shades of Purple

Upchurch

My biggest takeaway from last night is Michigan will need a very strong and well-coached front seven if Harbaugh is to pull a 1969 next Thanksgiving weekend.

The key to Michigan's dramatic defensive improvement in 2011 was that Brady Hoke and Greg Mattison gave Michigan's defense an identity. They went to a 4-3 under, single-gap run defense that Mattison brought from the Ravens, and over the course of the year found the best fits for the guys on hand.

Durkin knew Mattison from his Charlie Weis pants days. [photo: Joe Raymond|Freep]

You remember, despite the relative success of this transition, that some fits were more or less awkward than others. Jake Ryan was a perfect SAM. Ryan Van Bergen worked as a 3-tech or a 5-tech. Mike Martin played nose because nobody else could, and his disruption was deployed with a lot of stunts, or weird stuff like when they came up in an Okie and Martin dropped back to essentially MLB. Roh at WDE was a solid run defender but wasn't built to take advantage of that WDE-tackle matchup that's supposed to produce natural pressure.

Last year of course they went to a 4-3 over base alignment, making Jake Ryan into an awkward MLB because the alternative was Beyer as a really awkward 5-tech. The kicker: offenses were forcing Michigan to play nickel 50% to 90% of snaps, which made Ryan into either an undersized defensive end, or a guy on the sideline.

JMFR is gone but Mattison will still be around, joined by new defensive coordinator D.J. Durkin. At the Cleveland event last night I suggested Mattison’s role will be as sensei to Durkin, who hasn’t really flown solo yet (Muschamp was very involved with that defense).

It adds up to a belief that Michigan won’t change its defensive style for 2015, but what is that style? Coverages are another matter; just speaking to the front seven: should they be the under that they recruited for, or the over they transitioned to?

Refresher on 4-3 philosophy

Mattison and Durkin both coached (Durkin as a graduate assistant for one year) under Bob Davie at Notre Dame, who with Jackie Sherrill developed the Texas A&M "Wrecking Crew" defense. Jimmy Johnson (another Sherrill acolyte) took it a step further in Miami, and Pete Carroll now runs in Seattle.

You’ll note that they used different alignments. Johnson’s defenses were the genesis of the 4-3 over, and so influential that this is what people usually mean by “4-3” defense, as opposed to Tom Landry’s base version. Carroll’s been coaching the 4-3 under since he learned it directly from Monte Kiffin, who developed it at Nebraska.

The under alignment was not the base concept; the real philosophy in Kiffin's terms was to give his defensive linemen simple assignments so they could play with aggression and disruption. The benefit of one-gapping is no defensive linemen stopping to diagnose the play. Once the ball is snapped, all of these defenses want those brains thinking "go!", "put my hat in a gap," "be a factor," and "attack that block!"

Mattison used a mix in Baltimore because he had Ngata, but at Michigan he’s had an almost exclusively gap-attacking defense. The question has been what alignment to run it out of, and that’s a question of which players fit it best.

(Start at 1:17)

So which alignment is Michigan going with this year? I think again it’s a question of personnel? I make diagram.

Michigan’s short on red dudes

The above is my attempt at showing the spectrum of qualities emphasized by the front seven positions in the 4-3 over versus the 4-3 under. I also gave a small approximation of color fits for guys I know something about (Spur-like objects like Gant and Wangler left out because I ran out of colors to depict DB-ness).

It's meant to show what we mean when we talk about the why nothing's a perfect fit for the talent on hand. Suggestions for improved shading are welcome. Takeaway from this experiment: Michigan's front the next few years may be better at throwing out different looks than it will be at rotating through shark teeth.

If you trust my judgment on the shading above, the over appears to remain the best fit for the guys we have, provided they can find some backup ends (the glut of DE/DT tweeners remains). As Mattison mentioned in the video above, the half of the time you’re in nickel to counter a 3- or more-wide look, you’re in an over anyway. D.J. Durkin used a lot of smaller players and changed things up a ton at Florida, and I expect the future will be a truly multiple defense with versatile front seven players. I expect when they can’t run Ojemudia and Charlton out there at the ends, Durkin will experiment with linebacker-ish dudes out there.