defensive schemes

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.

I know Hoke said they spent the bye week on Michigan's "identity," by which we're pretty sure he meant scrapping any semblance of sense again in favor of slamming fullbacks into people and praying for the turnover fairy to stop hating us. But for those people actually interested in how to defeat Michigan State's lauded/loathed defense, it appears to be vulnerable when you spread 'em out and test them deep.

Quarters redux

You should remember how their thing works. The defensive backs read the inside (#2) receiver; if that guy goes vertical the DBs play cover 4; if that guy goes horizontal they play Cover 2.

Red: #2 receiver goes vertical. Blue: #2 receiver doesn't go vertical

With that many guys reading, the defense can play "9 in the box," by which they mean the safeties are part of the run fits. Their run D is gap-oriented.

Just an example. They change up who's got what

Note that screens and such are treated as runs.

[After the jump: tripping them up.]

This here Friday because not enough for Dear Diary.

What do you think of the transition to a 4-3 over? Who else is running it? Is it so much of a shift?

Ace: While I was skeptical at first—it felt like a bit like a panic move—I've started talking myself into this being a positive change. The main reason is that it should allow Michigan to generate more of a pass rush, and in less predictable ways. Seth pointed out the benefits for both Frank Clark and Brennen Beyer in his post—they slide into roles more suited to their abilities in a way that gets them on the field at the same time. Add in the ever-present threat of Jake Ryan blitzing up the middle and I think the pass-rush will be improved thanks to this switch.

When you have Clark and Beyer (and Ojemudia and Taco etc.) available this isn't the best use of Jake Ryan [Fuller]

The defense should also be better suited to go against spread attacks by keeping Ryan in the middle. He no longer has to worry about playing over slot receivers or being the primary defender against bubble screens, and when Michigan goes to a nickel, they'll most likely lift James Ross for a defensive back—adding coverage without losing much from the pass rush.

Keeping the linebackers clean against the run is also easier in a 4-3 over; Iowa's linebackers were very successful last year in part because their alignment allowed them to roam free sideline-to-sideline—I was dumb enough to confuse "DTs aren't making plays" for "DTs not doing their job" in that post, when it turned out Carl Davis and Louis Trinca-Passat were really good at holding up against double teams while the Hitchens/Morris/Kirksey trio combined for 35.5 TFLs despite rarely blitzing. I highly doubt Greg Mattison's defense will be as passive as Iowa's, but the Hawkeyes still provide a solid blueprint for how to get better production from the linebackers.

That brings me to my biggest concern, however, which is the defensive tackles. I believe the Henry/Pipkins combo will hold up fine at the nose, but the lack of experience at 3-tech is worrisome. The good news is both Chris Wormley and Matt Godin—the likely rotation there, along with Ryan Glasgow—were tweener DE/DT recruits with large frames, solid strength at the point of attack, and some concern about their edge-rushing ability; the last part matters much less now, and as long as they're not ceding ground with regularity, the experienced linebackers should be able to work behind them (Northwestern's linebackers managed to stand out in their 4-3 over even though their DTs routinely let the seas part).

My other main concern is how Ryan will handle more offensive linemen releasing to block him at the second level, but I have the feeling he'll figure it out. It's clear the coaches have been planning this shift for a while—see: Noah Furbush, MLB recruit—and despite a few minor bumps along the road I still have a great deal of trust in Mattison. If, as advertised, this shift allows the defense to be more aggressive in general and more adaptable against spread attacks specifically, I'm on board.

[Jump: Brian and BiSB go over this more. HA!]

In honor of our annual right there -----> which I expect will get Kickstarted a third year in a row today, I thought I'd share a little sneak peak from it. Brian asked me to create these for the linebackers page:

Click to big. Right-click to open in a separate window so you can reference it as you go.

That's a side by side comparison of Michigan's prohibitive starters this year before and after the "shift" to a 4-3 over and accompanying position changes were announced. Seeing it you can start to appreciate how all of those announcements make sense.

For the lay, what you're looking at are alignments of the front seven. The "under" shifts the defensive line away from the strength of the defense and the linebackers swing the opposite way to compensate. The result is very much like a 3-4 (picture the WDE in the photo above as yellow) and plays like it. In this alignment the strong side is the left because there's a TE there. Michigan would often align this to the hash rather than the offense, shifting the DL toward the sideline.

The "over" shifts the line the opposite way, but not to such an extreme. The linebackers wind up centered over the ball, and the DL spread across the formation. There is nothing 3-4 about it except the nose tackle.

Let's run through the positions to appreciate what's changed and what will be expected of them.

Weakside Defensive End (Frank Clark/Mario Ojemudia)

Ojemudia lined up as a 7-tech in the under [Fuller]

In the Under: The WDE is the leading pass rusher. He lines up so far outside of the backside offensive tackle that he'll wind up getting a 1-on-1 battle with that guy all day. The tradeoff was being further from the point of a attack in the run game. The WDE is further from the run game but in position to drop into coverage, a thing he was tasked to do quite often as the DE-like linebacker opposite him charged into the backfield. Much of the good done by the over shift is it creates double teams elsewhere to preserve the WDE's ability to attack upfield.

In the Over: The weakside end is still outside the offensive tackle, but shaded in a "5 technique," i.e. over the outside shoulder of the offensive tackle.

If you remember your 5-techs from 4-3 under school, you'll get the difference, though unlike your Ryan Van Bergens the weakside end usually doesn't have a tight end lined up to his side (ace even, H-backs and the like do happen) so he needn't be a double-team-eating anchor. The new WDE's biggest change is he's not dropping into coverage all the time. He has to control that OT in the run game, and often he has to cover the B gap. The linebackerity of the position has been removed; this man is a defensive lineman, and not necessarily a flashy one—Michigan State's been plugging their workhorse DE Marcus Rush in this spot for four years while various SDEs make the highlight reels.

The fit: Clark showed signs of being a pretty good player by the latter half of last season and now up near 260 he is large enough to not get kicked by OTs. As a pass rusher he's only like fifth or sixth in the conference, partly because the interior DL couldn't push the pocket very often, and partly because he wasn't great at closing when he beat his guy.  Ojemudia and true freshman Lawrence Marshall aren't large men in your memory, but both claim to be up to 250 now. They're all better full-time defensive ends than 3-4 OLBs.

[Jump for the rest of the DL—LBs coming up in Part II]

No Cam you don't get points for setting up Morgan's one-timer.

Still playing with the big spreadsheet of stats. Sometimes I glom onto something interesting and sometimes, like today, I waste a lot of time to realize a stat they track has no bearing on play at all, and then I have to write my article, and then Comcast manages to make me wish Greg Robinson was my internet provider and, well, that's my excuse.

While Ace was writing the MSU preview for this year's HTTV (you are welcome to pester Brian to start the kickstarter) I was feeding him various kill-me-now defensive stats that showed State was really good at defense last year. One thing we pulled up was a larger percentage of tackles that were assisted, something MSU seemed to share with other teams.

This does make sense if you think of plays that are good for a defense, e.g. a lot of bodies going nowhere at the point of attack, versus how long gains tend to end. Likewise you'd expect the position of the player to make a difference just because of the variance in amount of space between him and the next defender. A typical distribution of tackles was as follows:

Noise in the data: I built this from complete game stats, not play-by-play, so I couldn't separate special teams plays, etc. I did re-categorize a bunch of players listed at incorrect positions but I couldn't catch all of them. Tweener positions also throw things off: a WDE to a 4-3 under team is an outside linebacker to a 3-4 squad, 3-3-5 teams call the Spur a safety, Jake Ryan puts his hand down in the nickel, etc. There's tens of thousands of tackles in the above percentages but as we get into teams keep these inconsistencies in mind. FCS teams and stats accumulated against them were removed.

Who's doing the tackling? So in the above table defensive linemen have marginally more assisted tackles than linebackers, and both have significantly more tackles assisted than defensive backs. If tackle assists mean anything other than "more forward players are doing the tackling" we can see that by testing whether the % of tackles accrued by the front 7 or % of tackles assisted have a closer relationship to tempo-free defensive efficiency.

So yeah, it's where the tackle takes place, not some mystical ability of great defenses to get more people to arrive at the ball at the same time. And neither is that strong of a correlation. Sorry, every platitudinal defensive coach ever.

So how'd we do?

The Big Ten ranked by fewest yards ceded per play:

That Illinois and Michigan State are the top two teams at getting assists on their tackles says tackle assists aren't a thing. Rutgers was great at getting linebackers to the ball, but not until lots of yards had been accrued. Northwestern's a good study in this: in 2012 they had safety Ibraheim Campbell racking up Kovacsian solo tackle numbers, but in 2013 they had greater contributions from up front…with little increase in productivity.

I don't even see much in the way of stylistic preferences coming through. Michigan and Nebraska and Ohio State I believe (gleaned from what their coaches say at clinics mostly) are "spill" teams—they try to occupy blockers so a free hitter can make his way to the ball. Michigan State and Wisconsin and Penn State, are the ones I believe were "gap" teams—every defender has a gap he's responsible for closing.

So…okay, this stat means nothing. Good to know I guess.

Sorry this one's short, since I'm neck deep in the HTTV editorial right now. When we did the Marlin Q&A I shot him a question over email after the fact about his favorite type of defense. The answer I got back was very detailed, and mostly Greek to anyone who hasn't immersed themselves in it. I also thought it made a great snapshot answer to the question of what's the difference between college defense and pro/Alabama defense.

The question:

What's your favorite type of defense/base formation? Is there one that's more fun to play in and another that you think is the most effective, or are those one and the same?

My favorite type of defense is the 4-3  zone blitz with a mix of cov 4 and cov 2. My favorite coverage was one named Rolex, a mix of cov 4 and 2. DBs must read the number 2 receiver in order to know which cov to play, if 2 goes to the flat, outside corner comes off one and plays cov 2 while the safety pushes over the top of #1. If #2 goes vertical instead of to the flat, the safety takes #2 and the corner stays on #1 playing quarters cov.

Glossary (skip this part if you're already comfy with football terms)

4-3: The 4-3 you know: four linemen and three linebackers. Because the NFL plays with so many different fronts, specifying the base shift isn't necessary—they're going to align to what the offense shows and change it up three times before the snap to confuse the offense.

Zone blitz: Credited to the '71 Dolphins and popularized by LeBeau with the Bengals and Steelers. All it really means is dropping guys you'd expect to pass rush into coverage and blitzing from one of the guys you'd expect to be playing coverage. In a 4-3 defense it usually means a defensive end is in dropping into coverage and a linebacker or safety is blitzing. Granted your DEs are not going to be Ed Reed out there but it's effective because you screw up the OL's blocking assignments and you can get some quick picks from quarterbacks trained to throw in the direction of the extra rusher.

a typical cover-2 zone blitz

Cover 4 and Cover 2: Two basic defensive schemes for playing zone defense:

As you can see by the size and shape of the coverage zones, they have different strengths and weaknesses. Cover 2 is strong against short passing and is effective against the run because the linebackers don't have to go very far and the corners can keep that edge. It's weak to either side of the safeties, beaten by abusing the MLB deep or the spot on the sideline over the corner's head. Common routes to beat Cover 2 are seams, four-verts, and posts, which put receivers on either side of the safety's zone, or going high-low on the cornerback, making him pick between receivers running routes both under and over him.

Cover 4, also called "Quarters" is strong where Cover 2 is weak, and vice versa. You attack it by attacking the flat, for example with stop routes or making a linebacker carry a receiver/tight end to one side of his zone and having a back roll into the spot just vacated. You also can attack Cover 4 by running into it, but because the coverage just went back to normal for those safeties, and because the NFL has guys like Marlin, and Polamalu, and Ed Reed available to them, some coaches use this opportunity to line up one or two safeties in the box as supplemental run stoppers, trusting he'd have the speed to get back to a deep zone. Ohio State and Virginia Tech do a lot of this. The base quarters play is this:

The Flat: You should know this but it's the area between the hash marks and the sidelines within 10 yards of the line of scrimmage.

1 receiver, 2 receiver: Lots of coaches have different terms for the different receivers in any given formation, and defensive coaches have their own sets again for better kenning. In this terminology throw out all the stuff about slots and Y's and split ends versus flankers, and just think of the No.1 receiver as the outside guy.

Cover 2 and Cover 4 both split the field in half, so in the defensive back's mind he just needs to be watching to see what the receivers are doing on his side, hence the plural 1's and 2's.

High-Low: He didn't say that but it's what this play is trying to prevent. The cornerback on the right of this gif is getting high-low'ed:

In this case the corner plays it safe and decides to stay with the receiver running a flag to the top of the corner's zone, effectively forcing the corner to play a Cover 4 zone and abandon his Cover 2 zone, where there's now a tight end hanging out with a whole lot of nitrogen. Boom: high-low'ed.

If you look at left side of the above-gif'ed play, you can see they're running the other thing that beats Cover-2, putting the free safety in a bad choice (and requiring the cornerback to turn and carry the receiver out of his zone). If you start covering the flat and leave the #1 receiver to the safety, the offense can punish you deep and down the middle. Here the free safety was put in a bad choice between taking the tight end who's already behind the linebackers or a receiver who's behind his corner's zone. Boom: vert'ed.

But what if you could play Cover-4 when they try to verts you, and stay in your Cover-2 zone when they try to hit you in the flat?

This is Rolex

purple means it's a read

The point of this play is to take away one of the methods of beating Cover 2—going high-low on the cornerback—without opening something else up by having the safety and corner read the #2 receiver (for ease I've made this the tight end) and adjust accordingly.

In the example above, if Y goes into the flat, then the cornerback lets the receiver go and covers the flat, and the safety knows he is responsible for that receiver (who you're expecting to head out to corner). If the Y is running a vertical route the corner and safety play a Cover 4.

This Isn't Cover 4 or Cover 2

If you watch the linebackers' zones, it looks like a Cover 2, since the outside guys aren't covering the flats. From the offense's standpoint, the whole thing is playing havoc with the keys you've been drilled on since your first snap: the zone blitz means there's coverage in the direction the pressure is coming from, and though you recognize Cover 2 zones in the first few seconds of the play, when you go to throw the pass that's supposed to beat Cover 2, there's a cornerback or safety playing it super-aggressively.

Whole thing:

How to Beat It

It's a changeup, not a complete defense. Marlin didn't say what they do if the #2 receiver goes on a slant inside or something, but I think that plays right into the teeth of the defense; just double up the #1. I am confused about how they deal with the opposite high-low method:

…since the corner's read is going to drop him into Cover 4—perfect spot to intercept a ball to #2 but who's got #1 now? My guess is he just plays quarters with the linebacker (or in this case the SDE), who has responsibility for the flat. Also the SS is playing quarters so he's got his ears back.

Video:

Best I could find after watching lots of tape (Marlin failed to mention it was an Eagles defense until after I'd watched a lot of 2007 Colts). The #2 receiver stayed in to block, and the corner reads the backfield to be sure there isn't an RB trickling out into the flat, then leaps into Cover 4. The LBs are playing Cover 2. Another from that same guy.

Can we try this?

Mattison certainly played with this kinda stuff with the Ravens. But this year we're going to have at least one untrained safety, and the corners have about a year and a half of experience between the two starters. The thing about this play is it requires several defenders all to make the correct read and react to it quickly. It's the kind of advanced stuff that an NFL defense can install and practice until it's second-nature, but seems like a hard thing to get a young secondary to do. In the future, projecting that a handful of the defensive back recruits do work out, yeah I absolutely see Michigan trying stuff like this. Mattison loves his zone blitzes, and you could see in 2011 and last year that he wanted to put some more quarters and mixed coverage stuff in.