The 4-3 Under Defense, Part I: An Introduction

[RandomFan]

This is post #4 in the ongoing series from Field Gulls detailing the Seahawks (and now Falcons) defensive schemes. This one is from over 4 years ago, so some things have evolved since then and I will make some comments in red to denote that when neccessary. I also flipped the order I am posting these. I had started with more recent posts and was working my way towards the oldest; but decided to flip that around and post the oldest towards the newest in order to start building on the basic principles first.

http://www.fieldgulls.com/2011/5/31/2191847/the-pete-carroll-4-3-under-defense-part-i-an-introduction/in/4102067

By Danny Kelly @FieldGulls on May 31, 2011 (This is from 4 years ago)

The 4-3 Under defense is the base defensive package that the Seahawks run. (They also run a fair amount of 4-3 Over and 3-4 Bear fronts) Pete Carroll has been running this defense nearly his entire career, so as long as Carroll is the coach of the Seahawks, this is most likely the defense you're going to see on the field.

Carroll started his career out as a graduate assistant at Arkansas under Lou Holtz. At the time, the legendary Monte Kiffin was the defensive coordinator there and had been running a 4-3 defensive variation called the 4-3 Under- (he had run it for a few years prior at Nebraska, had installed it at Arkansas and later ran it while Carroll was with him in Minnesota in the NFL as well). Under Kiffin at Arkansas and Minnesota, Pete Carroll zeroed in on this defensive philosophy and he hasn't wavered from it since. Carroll said:

"When I started out coaching I spent three years as a graduate assistant. No one would hire me at first or even send me a rejection letter. A good friend of mine told me that there was a graduate assistant's job open at the University of Arkansas. That was the year Lou Holtz went there as the head coach. I got the position and it was the best thing that ever happened to me.

During that time I got to work with Monte Kiffin's staff on defense. He had been at Nebraska before he came to Arkansas. I think he is one of the best coaches in the United States. He is just an unbelievable coach. He ran a 4-3 under defense that he perfected at Nebraska and they won a national title and many conference titles while he was there in the 1970's. He brought that same defense to Arkansas. I have been running that same base defense since 1977 when I learned it from him. I have used variations of this defense my entire career. I have stayed with its principles through all my years of coaching. I have a real strong belief in this defense. I know the defense and its adjustments so well that my belief system in it is strong and rock solid."

The 4-3 Under, in it's simplest terms, is a gap control system meant to stop the run and to pressure the passer. For the most part, each lineman and linebacker is responsible for one gap - this makes each player's responsibility fairly cut and dry and eliminates a lot of the reads and thinking from the game. Now, the 4-3 Under can be run with 2-gapping personnel as well, and that was something that we saw Red Bryant and Colin Cole doing when they were healthy in 2010, but it really depends on if you have the horses to 2-gap or 1-gap in this system.

As a refresher, here is how the gap and defensive alignment system works.

You see the offensive line on the bottom of that picture as T, G, C, G, T, E. The space between each offensive lineman is a lettered gap. The A gaps are to each side of the center. The B gaps are to the outside shoulder of the guards. The C gaps are to outside shoulder of the tackles. The D gap is on the outside shoulder of a tight end, if he's there.

Similarly, the 'technique' numbering system designates where each defensive lineman lines himself up in relation to the offensive player. As you can see above, an even number 'technique' (0, 2, 4, 6) denotes that a defensive player is lined up helmet to helmet with the opposing offensive player. An odd number denotes that a defensive player is to line up offset from the offensive player. You may hear a lot about the 1-technique, the 3-technique, and the 5-technique in the Seahawks defense. I'll explain each of those as we go along.

In the late 1980's, Monte Kiffin began coaching for the Minnesota Vikings with a coach named Floyd Peters and they further developed the 4-3 Under that emphasized rushing the passer. The 4-3 Under system uses almost exclusively a staggered alignment to the offense in this basic set.

As you can see, in a basic 4-3 Under, the SAM linebacker is lined up to the outside shoulder of the tight end off the line of scrimmage a yard or two and is responsible for the D gap (to the outside of the tight end). He's also responsible for running in pass coverage from time to time.

The strongside defensive end is lined up to the outside shoulder of the tackle, in a 5-technique alignment, and is responsible for the C gap (to the right of the tackle). (Seattle has also evolved to line this player up in a 4-tech head up on the OT from time to time, in the base defense.)

The strongside defensive tackle (the 1-tech nose tackle) is usually lined up shading the center in a 1-technique alignment and is responsible for the strongside A gap. (He's generally responsible for both A gaps, covering up the WILL LBer to be able to run and tackle. He slants to the strongside A gap and is supposed attack that gap and push the Center back into the LOS and force the OG on that side to double team him. By forcing the Center back a yard or two, he's effectively blowing up both A gaps. But he's also got to be powerful and big enough to hold his ground and not get knocked off his feet from the double team of the OG. This is why a 330lbs Mebane or a 345lbs Soliai are perfectly suited for this role in the base defense. It would be a nearly impossible task for a 300 pounder to execute this role properly in the base defense on a regular basis. Yes, I know Mebane is listed at 310lbs for Seattle. No he's not really 310. Quinn said a few years ago that Mebane is actually 330lbs. So while a 300lbs NT will work in some base defense schemes, it's not desireable here because our base defense NT is designed to force double teams his way and still try to control 2 gaps. However, in nickel defense where OLs aren't trying to knock you off the ball, then size and girth is irrelevant.)

The weakside defensive tackle is lined up in a 3-technique alignment off the weakside guard and is responsible for the weakside B gap in front of him. (It's important to note that when we occassionaly slide over into a 4-3 Over look, this puts the normal 3-tech DT into the double team role instead of the 1-tech. This is why it's important to have a base 3-tech with the size and power of someone like Hageman who can occassionaly handle that duty. Again, in nickel D size is irrelevant.)

The weakside defensive end (Leo) is lined up to the outside shoulder of the weakside offensive tackle and is responsible for the C gap on his side.

This leaves the strongside B gap and the weakside A gap open. These are the responsibilities of the MIKE and WILL linebackers. (As I said above, they try as best they can to keep the WILL linebacker covered up by having the NT control both A gaps when possible. The Will can be asigned to cover the weakside A gap if the NT fails to do so, but his primary duty is to be able to run and tackle the ball carrier. It also helps that the SS is often walked down in the box and assumes the strongside B gap responsibility which allows the MLB to assume the weakside A gap if it needs to be filled. This completely frees up the WLB from any gap responsibility. This is why the WILL in this scheme can be a smaller guy, but he needs to be able to run like the wind.)

The 4-3 Under can be run with any combination of secondary assignments, the Cover-1, Cover-2, Cover-3, and even the Cover-4, and the Seahawks run different zone coverages at different times. The number in each "Cover" represents how many players are responsible in zone for the deep part of the field. In a Cover-1, the deep middle safety is responsible as help for the entire deep field, while all the other players are in man coverage. In a Cover-2, there are two safeties and they split the deep part of the field into two zones and help on routes in their zone. Cover three, one safety and two corners have 1/3 of the field as their respective zones. In Cover-4, also known as Quarters, the field is divided into four zones and each of the 4 defensive backs is responsible for his zone. In a Cover-0, each player is on a man and there is no zone help anywhere on the field. The other coverage you see the Hawks run is called the Tampa-2, which I'll delve into further a little later. (All of this is true, but they have evolved to using two coverages almost 100% of the time. About 80% of the time they run Cover-3 press zone, and the other 20ish% of the time they run Cover-1 press man.)

The defense that Pete Carroll now employs uses the basic tenets of the Monte Kiffin 4-3 Under defense and mixes in a variation originally pioneered by the legendary George Seifert in San Francisco. Seifert wanted to create mismatches against the opposing offensive line so he started using his weakside defensive end to rove around and rush the passer from a two-point stance (standing up position). This was the beginning of the "Elephant" position and one that Carroll uses today. We also see this position called the LEO, and in the Hawks' defense can rush standing up or in a three-point stance.

It's the same basic alignment but as you can see, the SAM linebacker comes up closer to the line to play hard contain and the weakside LEO is pushed out a bit, maybe a yard off of the weakside tackle. The LEO's main job is to control the C gap while rushing the passer like a wild banshee and the SAM plays contain against the TE, runs in pass coverage with him, or rushes the passer in some situations.

Here is the basic description of each position in the Pete Carroll 4-3 Under. In a continuing series, I'll get into more specifics about it, but I'll start you out with a general description. The LEO can be a little bit smaller than a normal DE and Pete Carroll tends to like a more athletic and versatile body type for his Elephant position; a guy that can speed rush the QB but also react quick enough to control his gap. Must also be able to drop back into coverage occasionally in zone blitz situations.

The strongside defensive tackle (1-tech NT) can be short and squat but must be able to take on a double team consistently. The weakside defensive tackle, the 3-tech, must be your premiere interior pass rusher and have an explosive first step. His main job is to pressure the QB and stop the run in his weakside B gap. The 5-tech defensive end can be a bigger guy and must be great against the run. This is why you saw Red Bryant move out there in 2010.

The SAM linebacker needs to be athletic and rangy; great against the run but able to run with tight ends and running backs in pass coverage. The WILL linebacker is going to get a lot of tackles and in Pete's system is typically a faster, smaller linebacker with range. The MIKE linebacker needs to be the field general; very instinctual and savvy. He needs to be quick enough to drop back down the middle third of the field in pass coverage in the Tampa-2 coverage. The free safety is a guy that's going to move around a lot and be very instinctual as well. He's going to come up to the line a lot and will get a lot of tackles. (The FS role has changed. He's almost always the deep safety now and is more of a coverage player than a true safety able to play in the box.) The strong safety has to be good against the run but like the free safety, will move around a lot and have to defend against the deep pass a lot. He will need to be fast and have some ball skills. (Because the FS role has changed, the SS role has changed accordingly. He's almost always the in-box safety that acts like a LB/SS hybrid. Rarely has to defend the deep pass.)

Finally, the cornerbacks need to be physical and long. They will get involved in run defense a lot so they must be good tacklers. They are protected over the top a lot of the time so typically they're not all-world defenders but need to be pretty fast. You see Pete running with solid, physical and tall corners but in his tenure at USC we didn't see any all-world prospects come into the NFL. (Straight line speed is more important than agility and change-of-direction. Although it's nice when you can have everything.)

Edited June 21, 2015 by RandomFan

[raysnill1]

man you killing it with these posts

[RandomFan]

Also, I think most everyone should know by now who is projected to line up where. But just in case there are some that still don't know, here is the current projection for the base defense heading into training camp. This only applies to the base defense; the nickel defense will have several differences. And obviously, things could change during camp.

There is no left side or right side, it's based on strong side and weak side. The strong side is determined by the TE lining up on that side. The side away from the TE is the weakside.

Strongside LBer: - Reed/Schofield

Strongside 5-tech DE: - Jackson/Clayborn

Strongside 1-tech NT: - Soliai

Weaskside 3-tech DT: - Hageman/Babs/Jarrett

Weakside Leo DE: - Beasley/Biermann

MLB: - Worrilow

WLB: - Durant

SS: - Willy Moore

FS: - R. Allen/Godfrey

LCB: Trufant

RCB: Alford

Edited June 21, 2015 by RandomFan

[Heavy Hitter]

Also, I think most everyone should know by now who is projected to line up where. But just in case there are some that still don't know, here is the current projection for the base defense heading into training camp. This only applies to the base defense; the nickel defense will have several differences. And obviously, things could change during camp.

There is no left side or right side, it's based on strong side and weak side. The strong side is determined by the TE lining up on that side. The side away from the TE is the weakside.

Strongside LBer: - Reed/Schofield

Strongside 5-tech DE: - Jackson/Clayborn

Strongside 1-tech NT: - Soliai

Weaskside 5-tech DT: - Hageman/Babs/Jarrett

Weakside Leo DE: - Beasley/Biermann

MLB: - Worrilow

WLB: - Durant

SS: - Willy Moore

FS: - R. Allen/Godfrey

LCB: Trufant

RCB: Alford

Good post. You had a typo though. It should be 3 Tech DT for Hag-Bab-GJ

[RandomFan]

Good post. You had a typo though. It should be 3 Tech DT for Hag-Bab-GJ

Thanks, fixed.

[DocMan]

Thanks for the education. Much appreciated!

[Fiddlin John Carson]

I been here awhile...these posts are some of the best ever posted. Thank you.

[antdaniels123]

Great post

[tone357]

I'm an offensive guy. All of this defensive technical jargon is making my eyes glaze over, but I can tell it's a good post. Thanks.

[Falcons_Frenzy]

Nice post

[Arturo.Zise]

Awesome post. Now I can read all this and take my Madden game to the next level ha ha.

[Durrty]

Awesome post. Now I can read all this and take my Madden game to the next level ha ha.

You know I was thinking that too?

As far as drafting goes, these posts are gonna help me build a monster on defense.

Excellent post OP.

[Shaggy 2.0]

Also, I think most everyone should know by now who is projected to line up where. But just in case there are some that still don't know, here is the current projection for the base defense heading into training camp. This only applies to the base defense; the nickel defense will have several differences. And obviously, things could change during camp.

There is no left side or right side, it's based on strong side and weak side. The strong side is determined by the TE lining up on that side. The side away from the TE is the weakside.

Strongside LBer: - Reed/Schofield

Strongside 5-tech DE: - Jackson/Clayborn

Strongside 1-tech NT: - Soliai

Weaskside 3-tech DT: - Hageman/Babs/Jarrett

Weakside Leo DE: - Beasley/Biermann

MLB: - Worrilow

WLB: - Durant

SS: - Willy Moore

FS: - R. Allen/Godfrey

LCB: Trufant

RCB: Alford

With our DTs, I think they all play each tech at some point. Jackson is really the only one who can't play all three. He could play strong and NT but rather not see him at weak side DT just because of his lack of speed but I could say the same for babs at strong side and lack of power at the LOS. However it's nice to see the potential of our front seven this year. Let's hope they gel and play as a unit! Go birds!

[blizzard_falcon]

With our DTs, I think they all play each tech at some point. Jackson is really the only one who can't play all three. He could play strong and NT but rather not see him at weak side DT just because of his lack of speed but I could say the same for babs at strong side and lack of power at the LOS. However it's nice to see the potential of our front seven this year. Let's hope they gel and play as a unit! Go birds!

Yeah, we'll definitely see them mixing players up here and there, especially on obvious passing downs. Quinn already said there's basically a base "big guy" package for run downs and a sub "pass rushing" package, one where Adrian Clayborn would move inside to rush the passer (similar to what Michael Bennett does in Seattle).

[RandomFan]

Yeah, we'll definitely see them mixing players up here and there, especially on obvious passing downs. Quinn already said there's basically a base "big guy" package for run downs and a sub "pass rushing" package, one where Adrian Clayborn would move inside to rush the passer (similar to what Michael Bennett does in Seattle).

Yep. I think it's interesting that we don't talk enough about the medium down and distance packages though. We talk alot about the obvious run-down package (the base defense), and we talk a good bit about the obvious passing downs (the nickel or NASCAR packages where it's all out pass rush and pass coverage. We all should know by now that on obvious run downs we'll have our 3 huge DL's in the game with a Leo rusher with 3 normal sized LBers and 4 DBs. We all know that on obvious passing downs we'll have zero big DL's in the game other than perhaps Clayborn and/or Babs/Jarrett (who are smallish anyway) with pass defenders behind them.

But we don't talk enough about the 2nd and 7's or the 3rd and 3's and whatnot. The medium down-and-distances (DnDs). The lineups where the offense has the option to run or pass equally. The lineups where you want to be able to still stop the run first and foremost, but also need to make sure to get a bit more of a pass rush than you can generate in the base defense with the 3 big boys on the DL. We've actually got some nice versatility for these packages with a few of the new additions. Not all nickel packages are created the same. Some are all out pass rush, some are a mix between pass rush and run stopping, some are still heavy run stopping with an extra DB thrown on the field.

Clayborn I think is going to be a big part of this puzzle. I still think Jackson is going to start at the 5T strongside DE in the base defense on obvious run downs. He'll also play some in these medium down and distance situations too. But being able to pull Jackson in these situations and bring in a guy like Clayborn on some of these downs where it could be run or pass is exactly what I'm talking about. Jackson is more one-dimensional. He's clearly a stuff the run guy that can give some pass rush push when he gets a one-on-one block. But Clayborn, he's more of a 2-way DE; a guy that isn't going to stuff the run like Jackson, but gives a better pass rush while not being a negative in the run game like it would be if we had, say Biermann or Beasley in that spot. I think Clayborn's role for this team is going to be not playing in the obvious run downs, splitting time with Jackson at DE in the medium down and distances, and playing a pass rushing DT in obvious passing downs. This means he wont be starting; but by the end of the year he'll probably have as many snaps as any other DL player. Not starting doesn't really reduce his value in the grand scheme of things. But splitting the load helps keep both him and Jackson fresher than if one were playing full time.

Biermann is another player I think might be seeing more time than many of us had hoped. Beasley is a rookie. I'm not sure we want him playing full time as a rookie; and this isn't even considering that Seattle has never once had a starting Leo that played more than the 73% of defensive snaps that Cliff Avril logged last year. That's 27% of the Leo snaps that went to someone else last year for them. I think our goal should be to minimize Beasley's responsibilities in order to help him play fast, and also keep him rested and fresh for the obvious pass rush situations since he's by far our best outside pass rusher. To that end I think we'll end up seeing someone like Biermann, Schofeild, or Goodman playing the Leo role much like Jackson will handle the 5T role - i.e. They will play in obvious run down and some medium DnDs, while Beasley also plays in some of the medium DnDs and probably all the obvious passing downs. Again, it keeps multiple players fresh, and will allow Beasley to focus on what he does best - pass rush; that should also help him avoid hitting the rookie wall late in the season.

Babs and Jarrett could also factor heavily in these medium DnDs too. There are many ways we can and will vary our front 4 personnel depending on the down and distance. One way already discussed is pulling Jax in favor of Clayborn. Another way will be pulling Soliai, sliding Hageman over to 1T, and bringing in Babs or Jarrett to play the 3T. This gives a tad more pass rush, while not totally abandoning the run game because we still have a big strong guy in Hageman that can hold up at the 1T if they decide to run the ball. We wouldn't want Hags there full time, but 10-15 snaps per game is something he should be able to handle. Sliding Hags over also helps us with one of our personnel problems - we have 3 guys that are built for the 3T in Hags, Babs, and Jarrett. That would help get all 3 more snaps. Theoretically, we could also have Babs or Jarrett handle the 1T role in such a scenario, but neither of them have the bulk or strength that Hageman does. Sliding Jackson over from his 5T position would also work well. Having 4 people able to handle that role in a mixed front look is actually a very nice thing.

We'll also see some fronts where there is no 1T, but two 3T DTs. Those two spots can be manned by any combination of Hageman, Babs, Jarrett, Jackson, or Clayborn. Heck, possibly even Goodman @ 265lbs depending on the DnD. The 2 DE spots could be filled with 2 Jet pass rushing ends, traditional run stopping ends, 2-way ends, or a mixture.

I could go on and on, but I think we get the point. We need to remember that when we're talking about our personnel, we shouldn't just be thinking about how they fit in the obvious run stopping base defense or the obvious pass rushing nickel/nascar defense; there are a lot of interesting packages in between those 2 that we'll see a lot of the time too.

Edited June 22, 2015 by RandomFan

[Da_Truth]

Thanks for the post. More great info on the 4-3 under defense. Many of us long time Falcon fans know how Monte Kiffin's defenses gave our offenses fits when he was there. It's always been a very solid scheme when you have the right personnel to run it. I can't wait to see us run the new defense in preseason. Seattle always played every game at a high level (including preseason). I expect to see the same level of play with the Falcons.

[falcon82111]

Great post and very informative. Enjoyed the refresher!!!!!

[Falcons&Dawgs#1Fan]

I believe a lot of the players we thought sucked and should be cut last year are actually going to be very good when placed in a defense that makes sense and puts the players in position to succeed instead of that idiotic scheme Nolan ran the last two years. Nolan took a pretty dam good playoff team and completely destroyed our defense with his nutty schemes and play calls, and old Smitty stood by and watched it happen.