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The 4-3 Under: Defining the Defense

The microphone is not allowed near his tongue.
The microphone is not allowed near his tongue.
Steve Dykes

This series is finally coming to a close. In taking the time to describe all of the different "base" alignments Washington runs we have covered:

· How Shaq Thompson really defines the defense

· The 4-3 Stack

· Nickel defenses (arguably the true answer thanks to Shaq)

· The 3-4

At SB Nation we have a feature called StoryStreams. It is a way to get articles covering the same topic or event together in one place. All of the articles about "Defining the Defense" (an impossible task, thank you Justin Wilcox) can be found in the StoryStream that should be to the right of this writing. On the bottom of the partial list is a link where you click ‘Full Stream.’ Heh, full stream. Earlier this week I thought about "Get Low" by Lil Jon. Now I am laughing at Full Stream. Maturation takes time, right?

Today we take a look at the 4-3 Under defense. This is my favorite defense for the sole reason that I know it better than any other defense. A tip of the cap to Danny Kelly at Field Gulls, he is the reason why I got interested in tape work. The 4-3 Under and 3-4 defense are two very similar defenses. I have heard the phrase "4-3 defense with 3-4 personnel" bandied about, and it really makes more sense to think about it that way than to think about it as a re-arranged 4-3.

Before we get into the details, you can think about the positions like this:

3-4 = 4-3 Under

Will = Will

Mike = Mike


Jack = WDE/Leo/Elephant



WDE = UT (Under Tackle)

Here is the 4-3 Under and the 3-4, respectively:





They both look like 5-2 defenses. In a way, they both are 5-2 defenses with tweaks, because every defense is different.

4-3 Under defenses try to do two things, two things that every front seven tries to do. One: stop the run. Two: pressure the pass. It uses 1-gap techniques to do so, which means that it relies on penetration and disruption of the offensive line.

The alignment of the 4-3 Under is meant to funnel strong-side runs to the Will. The D-linemen and SAM ‘backer all have to control their gaps at the LOS, allowing the Will and Mike to make plays. The way that the D aligns should allow the Will to be free and unblocked as well as funnel runs to him. The leading tacklers should be the Will and Mike, similar to the 3-4. On weak-side runs, both the Will and Mike should be flowing play-side, giving the SAM mop up duty.

That is a little bit on the philosophy of the 4-3 Under. Now onto the players.

Under Tackle

This is the defense’s namesake. He lines up at the 3-tech on the weak-side. The Under Tackle (UT) is an undersized DT who gets by on speed, quickness and technique. Sheer girth is not very important for this position, atypical for an interior line position. A lot of UTs are former DE’s who have shifted inside. Now, not all UT’s are the small, quick type. It depends on what the defensive coordinator wants for the situation and position.


If the defense is focused on stopping the run, oftentimes the UT will be a larger defender. He could be similar to a 3-4 DE. There is versatility in how this position could be used. The first star UT was Hall of Famer Warren Sapp. Sapp is an anomaly, a player with great size and strength in addition to quickness.

Typically, a DC wants his best interior pass rusher at the UT. Because he will be in a lot of one-on-one situations against a guard, the UT should be able to knife his way into the backfield and fluster the QB in addition to penetrating on run plays.

One of the main ideas of the 4-3 Under is to get defenders in one-on-one situations. Take a look again at the 4-3 Under on the chalkboard. How does a team (from 21 personnel, or even 12) double team anyone other than the NT? While the defense is predicated on getting one-on-one matchups, it is specifically designed to get the UT and the WDE into one-on-one situations.

When running a 4-3 Under, it is very, very, very important that the 3-tech UT is able to beat solo blocks consistently. More than consistently, frequently. Because the defense is so predicated on getting him those looks, it becomes almost necessary that he is able to dominate single blocks.

In case you haven’t noticed: the 3-tech under tackle is one of if not the number one most important player on this entire defense. His ability to rush the passer from the interior in addition to beating his blocker in hopes to stopping runs in the backfield is what the defense if predicated on.

Something that I found interesting: UW uses Danny Shelton at the UT spot frequently. I wish I could hear Wilcox’s explanation for this, as the NT spot is perfect for Shelton’s skill-set.

Other potential UT’s for UW: JoJo Mathis, Taniela Tupou, Connor Cree, Evan Hudson, Andrew Hudson, and Josh Banks.


The Nose Tackle in the 4-3 Under is a very simple position. He needs to be massive and powerful. He lines up between the center and guard (usually, sometimes he will line up in a ‘direct shade’ over the center) in a 1-tech or in a 2i (outside shoulder to the inside shoulder of the guard) on the strong side of the formation. In Wilcox’s schemes, the NT will line up over the center, atypical of many 4-3 under schemes.

The NT is one of the few 1-gap d-linemen with the task of controlling instead of attacking. He needs to be able to command a double team with his raw power. James Atoe is made to block these guys. Atoe is the heaviest player on the Huskies. When UW faces a top-tier NT, expect to see a lot more of Atoe than in other games, just because the sheer size of the junior is able to not get blown off the ball by overpowering strength.

Some defenses (I haven’t seen UW use this) use what is called a tilted nose tackle. The NT lines up in his normal spot, a 1-tech or a 2i. He then "tilts" his body, but really what he does is he faces the center. This allows him to use quickness to shoot the gap between the center and guard very quickly Steelers_medium_medium


What Wilcox likes to do is line the NG up at a 0-tech, directly over the center. His job is still the same thing: control the middle, draw a double team.


Strong Defensive End

The SDE is not a pass rusher. His purpose is literally the same as a 3-4 DE. Each scheme will use him a little differently, but his purpose is to control the OT, maybe draw a double from the TE, set the edge and control the C-gap on the strong-side. Simple. He can line up as a 4-, 5- or very rarely a 6-tech. If he is lined up at the 4-tech, he has B-gap responsibility.

The duty for defensive ends is similar to the nose tackle. Instead however, they are tasked with doing it to tackles instead of centers.

The most common position in a "true" 3-4 defense for a defensive end is the 4-technique. That is directly over the offensive tackle. The DE still lines up in several different spots, however. Some of the more common alternate spots are the 4i spot (shaded ever so slightly inside of the tackle) and the 5-tech. The 5-tech is also a very, very common spot.

But in the picture I am going to show you UW has their DE’s in 3-techniques. It goes to show how arbitrary the position designations are, and also how different the responsibilities are in different schemes. A 4-3 DE would struggle as a DE in a 3-4, and vice versa. The DEs playing here would have difficulty using a wide nine technique tasked with pinning their ears back and attacking Joe Southwick.

His job is to control the offensive tackle and draw double teams from the other blockers; it does not matter if the other blocker is a guard, tight end or running back, the DE wants to get their attention.

Think about this: if the nose occupies the center and the guard on one side, and the OT has his hands full with the defensive end, who is going to stop an OLB coming in? Who is going to stop an ILB shooting through one of the remaining gaps? When the 3-4 4-3 Under is executed perfectly, the linebackers are free and unblocked able to make plays.

The job is slightly different than the nose, however, and needs a different player. When dealing with offensive tackles, oftentimes the defender is dealing with the longest player on the football field. This means that if a stubby guy is trying to push him around, he will have trouble getting around and through the long arms of the tackle. One of the best ways to counteract this is with a long defender who still has strength and power. The best 4-technique on the Huskies is the 6’5" 280 lbs converted TE Evan Hudson. Hudson’s length helps him to better fight off the long arms of offensive linemen. His power still allows him to push around the tackle when he can get under the pads.

Potential SDEs: Cree, Hudson and Hudson, Mathis, Jarret Finau, Marcus Farria.


The LEO and Elephant designations aren’t something that Wilcox uses, but are used by a myriad of coaches within the 4-3 Under world, most notably by Pete Carroll of the Seattle Seahawks. He brought the scheme with him from USC, and it has served him well in the pros as well as in the college game. A little more on that later, but just a heads up.

WDEs line up in a nine-technique. Their wide (wide nine is a term used for a defensive scheme with both DE’s in nine-techniques) lineup gives them a better angle of attack on the QB than if he were lined up in a 5- or a 6-technique


The WDE is the team’s best edge rusher. He has to get after the QB with reckless abandon. Meanwhile, he has to maintain C-gap responsibility in the run game. This defender is an extremely agile fast-twitch athlete.

While he is flying at the quarterback like a bat out of Hell, he still can’t allow a run to bust through his side. He cannot allow the RB to get to the outside of him. If he cannot stop the RB in the C-gap, he must force the RB back inside, where the Will will be waiting. Remember how I said that the defense funneled strong-side runs to the Will? Sometimes weak-side runs are sent his way as well.

Carroll on the LEO:

"The best pass rusher on the team is usually the defensive end to the open side of the field. That puts him on the quarterback's blind side and makes him a C gap player in this defense. We often align him wider than this in order to give him a better angle of attack and allow him to play in space. We align him a yard outside of the offensive tackle most of the time. He has to play C gap run support but at the same time he is rushing the passer like it is third and ten. He has to be able to close down however if the tackle blocks down on him."

"(He) has to be one of your best football players. Size does not matter as much. We want an athletic player who can move around."


These three have almost the same responsibilities and require the same player as in the 3-4. Different schemes and different philosophies can change things, but they are basically the same players.

Washington does not flip their outside linebackers. They give them the designations of LOLB and ROLB depending on the game and matchup. They then take on the responsibilities of the Will or SAM, based on whether they are on the tight-end side or not.


Here is a link to the 3-4 defense breakdown, if you want to re-read the duties of these three linebackers.

In short:

The SAM lines up in a nine-technique outside of the SDE. He has the duty of forcing the ball-carrier back into the muddle that is the front-seven He has the control the edge on his side, not allowing running backs to get outside of him. He will run with the tight end in coverage if the defense is playing man, and will be tasked with shallow zones or with covering the flats in zone.

The Mike is the quarterback of the defense. He makes adjustments to the defense. Typically he will line up in a three-technique off of the line to the strong side. He has responsibility for the B-gap in run support. In man defense he takes the first running back out of the backfield. He typically will be responsible for short zones over the middle in zone, whether it be cover 1, 2, 3, 4 or 6. If the defense is playing a Tampa 2, he will run with the tight end if the tight end runs up the seam.

The Will requires the least size of all three linebackers. He should be unblocked, and has the duty to flow to the ballcarrier if his gap (weak-side A-gap) isn’t being immediately threatened. Like was mentioned before, the defense tries to force running plays to the Will, because he is unblocked. He will typically be the best cover linebacker, being the smallest and the quickest of the three, He has a shallow zone or the flat to his side of the field in zone, or the second running back out of the backfield.

Versus ‘Ace’

Ace personnel is when the offense is in 12 (one running back, two tight ends) personnel. The first tight end to the strong side is "covered" by the SAM linebacker. What happens to the other tight end? Regardless where he lines up, the free safety becomes responsible for him in man coverage. Zone is, obviously, different.


There you have it. The series is over. You are now an expert on defense. Right?