H4: Durkin's Defense is Not a 3-4

H4: Durkin's Defense is Not a 3-4

Submitted by Seth on March 24th, 2015 at 1:01 PM


No this isn't a "3-4"; well it is a 3-man front with the nose over the center,
but not a 3-4, let me explain.

Various people reporting back from practice have noticed three (or fewer) guys with their hands down, and said "oh they're going 3-4." Soon enough people pick up on this, figure a new DC means a new defense, and whiteboards across the state get sales points erased in favor of X's and O's with arrows diving between X's.

Mattison was asked about the 3-4 look in his breakout Q&A and had this to say:

"We ran that last year. What we're doing on defense is trying to see what scheme fits the players."

I know we've hashed the 4-3 under a bunch on this site but I could never walk by a boardroom with football drawings on it (this is probably why I lost that job) so here we go again.

Everyone Runs Everything. Calling a defense a "3-4" or "4-3" or any one thing at this level is not ever going to be accurate, because defenses change up gaps and show different looks so offensive linemen won't know exactly who's got what gap every time. In the process of showing that you might be running 3-4, sometimes you actually have guys two-gapping. If you have a really special player you might do that even more. But general rule is everyone runs everything, and the best you can do to describe any single defense is what their base is. Everything else will stem from the base.

Alignment vs. Philosophy

Alignment is where you put your players before the snap; philosophy is what they're being tasked with. The two-gapping philosophy has become synonymous with the 3-4 alignment, and the one-gapping philosophy is thus tied to the 4-3. The major difference between these philosophies is understood better by using the "gap" terms.


…means you have one to three defensive linemen responsible for controlling a blocker instead of a gap between those blockers. His job is to get into that guy and be in a position to tackle if the run goes to either side. He's not left out to dry; the two-gap philosophy gives you a free hitter from the second level who watches the play then reacts. Think of it as man defense for run fits, i.e. the defenders all have a certain offensive player they're responsible for beating, the free hitter's being the ballcarrier.

3-4 two-gap

You can do this if you have a super large nose tackle, the classic example being Wilfork on the Patriots. You can look at the above diagram and see the downside of two-gapping: if that left guard releases and the center holds up, you have a blocker eating your free hitter downfield. Two-gapping is a luxury you can have if the guy you have two-gapping is able to do it effectively.

A two-gapping defensive lineman needs to get that control established early, so lining up directly over the guy he's going to control is rather important. So a base 3-4, two-gapping defense will line up almost always with the nose tackle directly over the center, thus threatening the two-gap assignment, and still in position to change it up.

3-4 two-gap2

Remember that these are not set-in-stone gap assignments, just common ones. You change these up from play to play.


This is your basic "everyone has a gap" defense and the philosophy behind both the 4-3 even/over and 4-3 under. It is zone defense of run fits. Coaches who use this as their base, however, call it the more "aggressive," because football coaches describe the way they eat an ice cream cone "aggressive," yes, but also because the linebackers and linemen aren't diagnosing anything before taking their first steps of the play.

Instructively, one of the terms used often for the 4-3 over is the "Miami 4-3" because Jimmy Johnson used it to great effect when he had access to a lot of very athletic yet not very coachable defensive players. The concept was fast guys hitting their gaps and penetrating upfield to cause disruption.


You'll note that the 4-3 under picture is nearly identical to the 3-4, one-gapping example image above. That's pretty much what a 4-3 under is: a nose tackle and two large DL who set up in a position to take on double-teams so the LBs can attack their gaps. Philosophically everyone has one gap, but guys start taking on different roles: the NT is shaded to strongside so he'll need to be a bit more of a plugger; the SDE is further inside and has to be able to take on doubles like a DT; the other DT is further out and can be a little more end-ish; the WDE has a one-on-one battle with the OT, and can be a little more linebackerish; and the SAM has to be part-DE to compensate for the fact that he's the edge defender instead of the SDE.

Because it looks so much like the 3-4 defense it can threated to do 3-4 things. That gets us to the point of what Durkin does with his defenses, and what Michigan is expected to do this year: threaten two-gapping as a changeup.


Here's a play from Florida-FSU last year and you'll recognize the alignment as 3-4 (or would be 3-4 except weakside OLB is pulled for a nickel):


Nose tackle is right over the center. Ends are right over the tackles. You are thinking all sorts of Wilforky things. But this is still a one-gapping defense and you'll see why off the snap:


Right there is a good shot of the roles of 4-3 under defenders. The NT and 3-tech have double-teams; as long as they don't give up ground and stay engaged with those dudes they're keeping the LBs clean and keeping their holes closed. The five-tech has a guard (he'd be doubled if the run was going the other way), and the two MLB-types (the WLB and MLB) can flow into gaps (the MLB is blitzing his). The SAM has his edge. The difference here is the WDE has been pulled for a nickel, a dramatization of the fact that a 4-3 under WDE is often in coverage.

Here's how it's drawn up:

looks like a 3-4

(orange arrow means player's in zone coverage and watching his gap; black=rushing).

On that play the nickelback (5'10"/206 junior Brian Poole, Florida's hybrid space player) came down inside and got blocked by the slot receiver, giving up the edge and leading to a big run since the free safety was deep in coverage. If not for that, Poole should have been in perfect position to hold this down.

You Sure Durkin is a 4-3 Guy?

Durkin likes to accomplish the base thing from a gazillion different looks; I predict defensive UFRs with regular opening shots of Brian trying to name things. Here are the formations for every play leading up to that one:

FSU plays

What defense is this? It's a philosophically 4-3 (one-gapping) multiple-front thing that likes to have speed on the edges, either from standup WDE/SAMs or putting hybrid space players in there with edge responsibility. IE what Michigan's been since 2011.

What About 3-3-5?

The 3-3-5 stack also uses two-gapping as a base threat, though neither Rocky Long nor Jeff Casteel have often had access to a nose tackle capable of doing it consistently. The point of the 3-3-5 is it gives up starting position for the threat of attacking from anywhere.


Remember how GERG was terrible at this? It's because he was a 4-3 coach teaching 4-3 philosophy, and that took away the unpredictability of this defense.

More On Next Year's Front

More On Next Year's Front

Submitted by Brian on February 8th, 2012 at 2:12 PM


no pressure, Ondre

As part of the run up to the Super Bowl, Smart Football posted a Grantland article detailing the Patriots' defense. It's not much good at football, that defense, but it is pretty interesting from the Michigan perspective for two reasons.

Reason one: it provides an excuse for Chris Brown to talk about techniques in an easy to understand way.

"Gap" refers to the area between offensive linemen. A 1-gap technique is just what it sounds like: The defensive lineman lines up in front of the gap he is responsible for and his job is to attack and control it. If nothing else, a defender must not allow a runner to go through his gap. While defensive linemen attack their gaps, the linebackers behind them are responsible for their own gaps. These are the defense's "run fits," meaning how they fit into an offense's blocking scheme to take away running space.

Diagram 3
Courtesy of Chris Brown

The 2-gap technique, by contrast, sounds physically impossible. How can one player occupy two separate gaps? He does it by controlling the blocker. At the snap of the football, a two-gapping defensive lineman does what Wilfork did to Birk. He leads with his hands, gets leverage on the offensive lineman, and takes control of the blocker. From there, the advanced techniques kick in. On run plays, the defender reacts to where the blocker tries to take him. If he is double-teamed, he'll try to split the blockers and either shoot into the backfield or occupy the blockers, thus freeing up his teammates to make tackles.

In short, while a 1-gap player attacks gaps, a 2-gap player attacks people. Football's conventional wisdom states that an effective 2-gap lineman, particularly one who lines up in the middle of the defense like Wilfork does, must be enormous. Coaches refer to them as "war daddies." But size is actually less important than athleticism and smarts. The line between touchdowns and stops in the NFL is exceedingly thin, and it's footwork and feel that are the difference. It is the most violent, most complicated, and most beautiful ballet I can think of.

Count the war daddies on the Michigan defensive line. You come back with a true freshman and an inconsistent former five star who can't play consistently without standing up straight. The other guy who would be two-gapping in a 3-4 is… Nate Brink? Jibreel Black? A true freshman? Not happening.

This matters much more than a surfeit of linebackers when you're trying to pick a defense to run, especially when moving to a two-gap system does not get more of them on the field. The 3-4 is not coming to Michigan.

At least not in total. We might see bits and pieces, though…

Reason two is an interesting adjustment the Patriots have made to adapt to their personnel. Wilfork is a monster they would like to use to the maximum extent possible, which means two-gapping him. Asking him to be Mike Martin is a lot like asking Ondre Pipkins to run a bunch of goofy pass-rush stunts like he did in the AA game. But because of deficiencies elsewhere Bill Belichick (mainly a 3-4 guy) feels compelled to run a 4-3, which generally means one-gapping.

What to do?

The Patriots run a 3-4 to one side of the field and a 4-3 to the other, all on the same play. The key to all this is Wilfork. He lines up over the center and assumes his traditional spot of run-stuffing, blocker consuming, two-gapping war daddy. Belichick fills out the rest of the pieces based on the strengths and weaknesses of his other defenders.


Create a hybrid. This is the Patriots' under front, one similar to what Michigan ran this year except with one planetoid defensive tackle and one strong-and-good strongside defensive two-gapping. This might be something we see from Michigan next year. Getting maximum production out of Pipkins basically demands something similar.

The problem here is still the same one we have when we theorize about moving to a 3-4, though: there is no SDE on the roster with a prayer of being able to two-gap anything. If you try to get clever by flipping Campbell out there you're asking for it when that tight end goes in motion to the other side of the line and you're either rearranging the entire DL on the fly or running this:


Your weakside DE is not a pass rush threat at all. So don't expect this next year.

HOWEVA, even if you shouldn't go around calling the defense "basically Belichick's" yet, we should expect Pipkins' deployment to be radically different than Martin's. That should mean fewer blocks getting to the linebackers and more plays from that unit. If the ILBs find a surge in productivity it will be because of Pipkins—not because he is a better player than Martin, but because he's a different one.

You'll be able to tell if this is happening by Pipkins's alignment. Martin played a "shade"—he aligned in the gap between the center and guard. If Michigan wants Pipkins to be Wilfork they'll put him nose to nose with the center and say "sic 'em."


This is where disclaimers go. Even with New England doing this a major theme of the first half in the Super Bowl was that one-gap backside tackle getting doubled (often on zone runs) and blown up. It is never as simple as "this guy gets one on one blocking." All you can do is change the equation so that doing that exposes someone else to a tough assignment. You can't entirely cover up for a sucky player.

Pipkins may be talented but there's more to playing nose tackle than talent. You can dominate your guy, push him into the backfield, and still screw up if you lose control of one of your gaps. Usually this happens when the DT gets pushed too far in the direction he wants to go and opens up a cutback lane behind him. When one of these players is Gabe Watson and the other is Pat Massey, pain results. It's not too hard to envision that happening what with Will Campbell still a rotation player you're a little afraid of. At least he's not 6'8"*.

It may make more sense to start Pipkins off with the easier assignment (always one-gap) and hope to make him impactful in two gaps later in his career. That'll be one of the interesting tactical decisions we unveil against… oh, Christ. Alabama. Yay!

*[Who in the hell looked at a 6'8", 260 pound player and put him on defense? That is either a tackle or a tight end or a man who should be playing basketball.]