The 4-3 Under: Think 3-4 personnel and recruiting makes sense

Submitted by JeepinBen on December 23rd, 2011 at 11:18 AM

[Ed-S: Festivus Bump!]

In modern football, there are 2 popular base defensive sets. Most teams run either a 3-4 Base or a 4-3 Base.

The quick explanation of these defenses is that the first number (“3” in a 3-4) is your number of Down Linemen (literally people who line up with their hand on the ground in a 3 or 4 point stance on the line of scrimmage) and the second number (“4” in a 3-4) is your number of linebackers (people who line up in a 2 point stance, behind the down linemen).

This diary will discuss the 4-3 Under, its similarities to a 3-4 set, and make sense of our defensive line recruiting. For the purposes of this diary I’m ignoring the secondary. You need corners and safeties. They’re all similarly sized players, get fast ones. The front 7 is where you need guys over a 100lb range and some more major differences show up.

Here’s a base 4-3:

Here's a base 3-4:

Both of these defensive base sets have advantages and disadvantages, and both lend themselves to different styles of players. When it comes to what Michigan is running as a base defense, the 4-3 Under, recruiting starts to make sense if you look at it as a 3-4 defense.

The 4-3 Under:

First, look at the D Line from the middle out. In a 4-3 Under you have a defensive tackle on the Nose, in a 0 or 1 Technique (NT)  (Technique definitions:


You then have 2 players lining up at the 3 tech (DT) and 5 tech (SDE). Then you have 2 players further out on the line, at a 7 tech (WDE) and 9 Tech (SAM). Finally, you have 2 linebackers off the line of scrimmage (MIKE and WILL).

Now, compare these positions to the 3-4 Base. You still have a huge space-eating Nose Tackle (NT) who lines up at the 0 or 1 tech, 2 Defensive Ends over the guards, tackles, or in between (4 tech... hmmm, just a slight shift from the 3 or 5 tech...) and 2 people outside of them near the line of Scrimmage (OLBs). Finally you have 2 linebackers off the line of scrimmage (MIKE and WILL). 

If you look at these two defenses, the only main difference is one of your 3-4 OLBs has his hand on the ground. That’s it! There are minor shifts on the line and other intricacies, but big picture the 4-3 under has personnel requirements very similar to a 3-4.

For the 4-3 Under OR the 3-4 in your front 7 personnel you need:


1.) A Space eating Nose Tackle (or at least one who can stand up to double teams)
2011: Mike Martin
2012 Recruit: Pipkins
2.-3.) 2 players with good size who can go against guards or tackles, defend the run, get penetration and rush the passer. (3-4 DEs or 4-3 Under 3 and 5 Techs)
2011: Heininger and RVB
2012 Recruit: Strobel, Wormley, Godin
4.-5.) 2 players with speed who can set the edge, keep contain, rush the passer, and drop into coverage occasionally (3-4 OLBs or 4-3 Under WDE and SAM. In the 4-3 Under 1 will rush the passer more often, 1 will drop into coverage more often, but both do both)
2011: Craig Roh and Jake Ryan
2012 Recruit: Ojemudia and (I can’t remember which LB projects here)
6.-7.) 2 players who make tackles. Always flow to the ball, can shed blocks, cover, and make plays (MIKE and WILL)
2011: Demens and Morgon/Hawthorne/Herron Combo
2012 Recruit: Ross, Bolden, RJS and Ringer (whoever doesn’t project to SAM)
In pass rush situations, most 3-4 Teams will run their NT off the field for an extra DB, and rush 4 with their 2 DEs and their 2 OLBs. Most 4-3 teams will sub a linebacker for a DB.
Michigan subbed Heininger (not the NT, but Martin is a better pass rusher than a prototype NT) for Avery and put Ryan on the line, just like 3-4 teams do. My guess is this continues next year, we run off a DL and let Ryan put his hand down.
As far as speculation that Michigan is loading up on linebackers, SDE types, and WDE types without taking 2 huge DTs in the class because we might switch to a 3-4 base... we kind of already have a package that uses 3-4 base type personnel. In the 4-3 Under, like a 3-4, you want flexibility in your defense. The following positions are relatively interchangeable in a 4-3 Under, don’t get caught up on DT vs. DE or DE vs LB:
  • 3-Tech DT and SDE (5-Tech)
  • WDE and SAM

Michigan is recruiting the right numbers for the scheme they run. These are 17-year-old guys we’re discussing with recruits. Some will get bigger, some are maxed out. Some of the WDE/SAM types will be better at coverage and will play SAM. We saw Frank Clark and Beyer make this switch this year, one was a LB, one a DE in High School, and they switched at Michigan. Some will be better pass rushers and will drop into coverage less at the WDE.

The “Glut” at SDE doesn’t exist since the 3-Tech DT is a very similar position in the 4-3 Under, so some of these guys will play there. The coaches know what they need to run the 4-3 under, and hopefully this diary provided some insight into the personnel requirements so we can somewhat understand the method to the madness.

(Note competence)



December 25th, 2011 at 9:30 PM ^

troll, who's comment was likely deleted. Jeepin was replying to him, but since the troll's comment was deleted, it now looks line he was replying to you

I can see this through the magic of the mobile app, which continues to display deleted comments (i.e. I can still see the troll's weak sauce taunt)


December 23rd, 2011 at 11:57 AM ^

The pictures of the 4-3 base and 4-3 under look like they have the ends and tackles in the exact same place.  I have very limited knowledge of defenses, what am I missing?


December 23rd, 2011 at 12:18 PM ^

Those figures do look basically the same wrt to the DL.

I could be off-base here, but in the under I think the interior players generally have 2-gap assignment - that is, they tend to play straight up against the OL in front of them, so they can come off and make a play in the gaps to either side.

In a base 4-3 I believe 1-gap assignments are more common, so the DL will line up in the gaps between the OL. This seems like a minor detail that ends up having major implications on the kind of players you need.

People more knowledgable than I (and there are many of those) should jump in...

Blue in Seattle

December 23rd, 2011 at 1:18 PM ^

teaching players to defend 1-gap over 2-gap is the biggest learning curve between the schemes.  Brian linked to multiple articles over spring and summer like teh Smart Football blog, etc. that talked about these differences.  One avantage of the 1-gap is there is less to teach each player, and probably is why it's only attempted more often in the NFL.  This point was why I believed there is no way Mattison is changing from a 4-3 under scheme, since he's already investe a whle year teaching the technique of this scheme to all the DL position.

A big player that everyone leaves out of this discussion us Will Campbell, and specifically as Mike Martin's replacement.  In the last 3-4 games it seemed to me that Will Campbell was subbing in at the 1-tech.  That means to me that Pipkins is positione as the 1-tech backup behind Will Campbell.  Is it possible he earns the starting position?  With this staff of course!  But is it likely a true freshman picks up enough of the technique to become the starter in Sept?  I don't think that's likely.



December 23rd, 2011 at 1:36 PM ^

Yeah, I thought that 4-3 base has what they call an "under shift" with the tackles imbalanced.  A 4-3 base would have a balanced line that would basically have two Mike Martin's: explosive into the backfield, but strong enough to hold up against a double team.


December 23rd, 2011 at 5:35 PM ^

In the base diagram, there is no tight end. This is where the confusion comes from.

If you put a TE into the picture, the formation changes. Different coaches will want to handle it differently, but the most common alignment is probably to shift the line "over" with the 3-tech to the strong side of the offense, and the 5-tech moved out either covering the TE or to his inside half. That would put the nose on the weak side.

That is assuming you want to stay in a base 4-3 with stacked backers. A lot of coaches would just shift the D into an under, with the Sam on the line over the TE.


December 23rd, 2011 at 12:49 PM ^

Nice work - a very helpful summary.  Seems like you confused Chris Rock (NTCR) with Brennan Beyer, as it was Beyer who switched from WDE to SAM.  Rock will likely be one of those 3 tech/5 tech swing guys.  As for projecting which of the four LB recruits will be the SAM, I think even the coaches are not certain until they see them on the field, but perhaps RJS has the closest to ideal SAM physical attributes.


December 23rd, 2011 at 1:31 PM ^

He would also project as an edge setting LB. The 2011 class (and Jake Ryan) look to be almost evenly split between tacklers--Poole, Morgan--and edge setters--Ryan, Beyer, and Clark. Adding Ojemudia, it looks like the 2012 class is primarily stocking up on tacklers as depth is  strong on the edge. Given the experience from 2008-2010, any semblance of a defensive plan moving forward is promising. With Mattison calling that shots, I am very optimistic about our defensive prospects in the next 5 years.


December 23rd, 2011 at 2:26 PM ^

A very helpful reminder that the 4-3 under is in many ways more like the 3-4 than the classic 4-3. This makes me (a little) less nervous about us taking only one true DT in the 2012 class. Wormley and Godin seem like guys who will eventually grow nicely into that 3-tech DT/5-tech SDE role that Van Bergen was so effective in this year.

My question for the original poster would be: Who among the returning interior D-lineman (Campbell, Washington, Ash, Wilkins, Brink) do you see slotting in to the NT, 3-tech DT, and 5-tech SDE positions next year w/the departure of Martin, RVB, and Heininger?


December 23rd, 2011 at 3:06 PM ^

I know that Ash is slotted into the NT spot, but I don't know where on the depth chart. If I had to guess... we'll see:

NT: Campbell, Ash, Pipkins

3-Tech: Washington, Brink ????

5 - Tech: Wilkins, ???

At this point those question marks are probably the Freshmen, Godin, Strobel and Wormley. 

While the 3 and 5 techs require similar body types, the intracacies of each are different, and I dunno who would be most successful where. Campbell did spell Martin at times towards the end of the year at the NT, I'd be very surprised if it isn't his spot to lose next year.


December 23rd, 2011 at 6:16 PM ^

The 3 Tech/5 Tech slots are wide open for next year.  I agree that Q will get the first call at 3 Tech (and can move inside to NT) but past that it will be a battle between Brink (if he can put on 20 lbs. of good weight), Wilkins, Rock, Heitzman, and the freshman trio of Strobel, Wormley & Godin.


December 23rd, 2011 at 4:39 PM ^

This all makes sense but the staff is putting a lot of trust in Pipkins by taking one NT.   It would have been nice to see one more monster on the d-line (NT) as a security blanket.  Hoke is filling the o-line very nicely with quality and quantity and I would have liked one more stud on the inside of the d-line.   My point is Big Will was a 5 star out of high school and has been meh at best.   And the others have done a bunch of nothing so far.  

steve sharik

December 23rd, 2011 at 10:51 PM ^

  1. Readers should note that the defensive technique numbers, while similar, are different from what you hear from the M coaching staff.  A 5-technique to the OP is head up an OT, while a 5-tech to the M staff (and most coaches) is outside shade of the OT.
  2. Under/Over are defensive fronts originally created by 50-front guys.  The 50 fronts are more similar to the 3-4 since both are "odd" defenses; i.e., fronts with an odd number of DTs, and always having a nose guard over the center.
  3. 40 defenses adopted the Under front as a way to get more players on the LOS, with a stand-up player coming down, usually the SAM backer as the strong-side 9-technique with the 4 DL shifting toward the weak side.
  4. I disagree that 3-4 coaches like to 2-gap.  Some do, but some like to slant, angle, or involve some other kind of movement 90+% of the time, in order to get their players into one defined gap.  I don't think I've ever seen anyone who plays a 4-man DL have their guys 2-gap.

Mods, this is not a quality post on football scheme and techniques.  You need to find someone who is qualified to screen these posts before front-paging them, just as you would for a post on other factual subjects.  Putting this post on the front page damages the credibility of this blog, in my opinion.


December 24th, 2011 at 3:41 PM ^

I'm sorry, but did you read the post? I'll agree that it's not a "quality post on football scheme and techniques" because it's not a post on scheme or techniques. It's aobut the athletes we're recruiting, and the body types we need at certain positions. I don't mention gap responsibility anywhere, because that wasn't the focus of the diary. If you're going to attack my credibility, at least read the damn title. 

steve sharik

December 25th, 2011 at 1:14 PM ^

In a base 5-2, the nose is head up the center, the DTs are head up on the OTs, and the DEs are head up on the TEs (or "ghost" TE if there is none).  In "under," the weak side DE and DT reduce down over the OT and OG, while the nose shades the center to the strong side.  In "over," the strong side DE and DT reduce down over the OT and OG, while the nose shades the center to the weak side.  I'll do some diagrams if I have time.


December 24th, 2011 at 11:02 AM ^

Excellent post thanks, a few comments.

1.  The point that the 3-4 and 4-3 under aren't too far apart is also made in this 11W post that some might find helpful as a second look.

2.  A difference obviously is that in the 4-3U the WDE is more endy, while in the 3-4 the OLB on that side is more linebacker.  Even so, the 2 OLBs in the 3-4 can have different points of emphasis and responsibilities.  Notre Dame calls them Cat and Dog and 1 has more rush responsibilities (Cat) and 1 has more coverage responsibilities (Dog).

3.  The similarities b/n the 3-4 and 4-3U may be brought more in relief by comparing botht o the 4-3 over.  I'm no expert but I think that the 4-3O has less specialized positions, lining up all 3 LBs across.


December 24th, 2011 at 11:50 AM ^

Good Stuff & the commenters too.

IMO, thinking about it this way also makes it clearer as to why the initial reaction is to flip the D-Line when the offense shifts it's strength (something a lot of people complained about early in the season).  Plus kids learning a new scheme in general.

I think with experience, the need to flip-flop your linemen when a TE switches sides after lining up goes away.  You can just shift down.


December 25th, 2011 at 12:57 AM ^

this is what makes this blog so superior to other blogs. This kind of depth of knowledge and discussion is unparalleled in any other blog I've ever been to.


December 25th, 2011 at 5:26 PM ^

Even though a 3-4 and to an extent the 4-3 under utilize only one main NT, why aren't we getting another NT recruit? I feel like we need another in case somebody doesn't turn out down the road. ( I haven't watched pipkins on film so maybe someone who has can give me the answer to my probably stupid question)


December 26th, 2011 at 4:03 PM ^

But Pipkins is a highly regarded 4* recruit who the coaches have seen a lot of. He's rumored to be pretty college-ready and could fight for playing time next year. We'll also have a total of 4 guys on the roster who could be the NT (Campbell, QWash, Ash, Pipkins) next year. My guess is we'll be taking at least 1 NT type every year, but for next year we should have enough depth with just Pipkins