Discussing 40 fronts

Yesterday, I wrote a post about terminology on defensive fronts.  Today, as a follow-on, I want to talk about two of the five major base defensive fronts.  These base looks have variants situationally, but they each lean on certain major concepts.  As we approach more actual preseason games, I thought it would be fun if we got into some technical stuff today.

Remember, the word “technique” in this concept means nothing more than where a player is going to line up, in relation to the offensive line.  The overriding idea behind all of these fronts is that the defense is seeking to dictate to the offense how they want to be blocked.  That may not completely make sense at this moment, but as we go, I hope it becomes increasingly clear.

40 Fronts

A 40 front has four down linemen, and some other number of linebackers.  I don’t like to talk about 4-3′s or 3-4′s at a high level, because the number of LBs isn’t always so clear, and it can change.  For that reason, when I’m being general, I always reference 40 and 30 fronts.

That said, sometimes a 40 front is actually a 4-3.  There are two types of base 4-3 alignments that you see a lot in the NFL.  We’re going to cover them both, and talk a bit about variations in alignment from the base, and which teams use these kind of looks.

Tampa-2 schemes use a base 4-3, and tend to be one-gap schemes.  By that, I mean that each defensive lineman is attempting to penetrate and control an assigned gap, and the Linebackers behind them also have assigned gaps in the running game.  Those gap assignments are often called run-fits, and it’s very important that each player maintain discipline, and good leverage within their gap.  This style of defensive front is very aggressive, and tends to favor speed in its players.

The first thing you’ll notice is that the D-line is not directionally even.  On the strong side (meaning the side where the offense has a Tight End), the Defensive End is in a 7-technique, so he’s actually wide of the TE.  A DT is in a 3-technique alignment, which is almost always the case in this scheme.  There’s another DT, who’s actually a Nose Tackle, and he tends to play a zero or 1-technique on the opposite side of the Center from the 3-technique.  Finally, the weakside DE plays a 5-technique.

I want to digress for a moment to make a tangential point about the craptasticness of football’s mainstream media.  Most writers think that “5-technique” means a DE in a 3-4, and that only 3-4′s have NTs.  Neither thing is remotely true, which you’re about to see repeatedly.  I can’t tell you how many times a big DE gets described as more of a 5T than a 4-3 DE.  Don’t be that guy.  Rather, you might want to say a guy may be more suited for a 2-gap scheme if he’s bigger.  That’s a potentially intelligent thing to say.

Remember, always, in the context of defensive fronts, the word technique simply means where a player lines up, in relation to the offensive line.  That is a key point, which is why I’ve now written it three times in two days.

OK, back to the technical stuff.  Remember our gaps from yesterday?  There are six main gaps; A, B, and C gaps on either side of the Center, right?  Here’s yesterday’s diagram to help us visualize this.


You actually have to remember to count both edges as areas of responsibility, too.  They aren’t really gaps, per se, but they have to be accounted for like gaps.  So, if there are six gaps, and two edges, that means there are 8 run-fits that have to be maintained on any running play.  A standard front only has seven men, right?  You either have to control eight run-fits with seven men, or you have to bring an eighth man into the front.

In this kind of front, there are the assigned gaps that we talked about.  The 7T has the strongside edge, the Sam LB has the strongside C gap, the 3T has the strongside B gap, the Mike LB has the strongside A gap, and the 1T has the weakside A gap.  The 5T DE has the weakside C gap.  That leaves both the weakside B gap and the weakside edge to theoretically be accounted for by the Will LB.  He’s going to probably err to the side of covering the edge, because his pursuit is coming from inside, and he has safeties to fill from in there as well.  If the Will elects to fill the B gap, the Safety has to see that, and get out the edge.  This is the essence of run defense, covering the 8 run-fits, regardless of the type of front, so I wanted to get a little bit detailed with it.

From a pass-rush standpoint, the goal of a Tampa-2 scheme is always to get pressure with 4 men, and to drop 7 into coverage.  There’s absolutely no mystery to it, and anybody who’s ever played Madden knows exactly what it looks like.  Our four D-linemen are going to whip your five O-linemen, and your five eligible receivers aren’t going to get open enough against our back seven.  To beat a well-staffed Tampa-2, you have to pound them with the running game, and force them to commit the extra safety to the box.

Teams who I expect will run this sort of scheme include Indianapolis, Minnesota, Chicago, the New York Giants, Seattle, and Tampa Bay.  Tampa lacks much outside pass rush though, so they may blitz a lot this season.  The same may be true of Seattle in the short term.  While Pete Carroll is a lifelong Cover-2 guy, his USC teams blitzed and played Cover-1 plenty when he lacked edge rushers.

I called this diagram a Run Contain 4-3, but it could just as aptly be called a traditional 4-3.  Conceptually, this works much like a Fairbanks-Bullough 3-4, in that the inside players are two-gapping.  Note that both DTs are aligned head-up on the Guards in a 2-technique position.  This take on the 4-3 calls for these to be huge, powerful guys.  Think of the great Baltimore defenses of the early 00s with Tony Siragusa and Sam Adams inside, and you have the right idea.

Those huge DTs are going to engage with the guards, and move in the direction of the play, to either the A or B gap on their side.  The LBs behind them are reading that action, and they’re ready to fill in the open gaps.  The two seven-technique DEs tend to be tasked with setting the edge in this scheme, and the two OLBs are typically responsible for the C gaps on their side, and to help with plugging the B gaps.  The key guy is the Mike, because he has to work from B gap to B gap, and he’s going to have to read his DTs on the fly, while shedding a lot of combo blocks from the interior offensive linemen.

The whole idea of this scheme is to stop the run with seven men, and allow the safeties to stay back to play deep halves of the field in the passing game.  With the big DTs, you’re generally sacrificing some inside pass rush, so you need quick DEs who can beat OTs off the edge.  Jason Taylor often made Jim Bates’ defense look excellent in Miami, with his ability to do so.

Teams who employ this kind of strategy include Tennessee, Buffalo, Jacksonville, Oakland, Atlanta, Detroit, Carolina, Cincinnati, Houston, and New Orleans.  I’m a little reluctant to include the Saints, because they blitz significantly more than the rest in the passing game, but their run defense scheme is most similar to what we’re talking about here.

Sometime tomorrow, I’ll talk about 30 fronts and hybrid schemes.  I hope you’re enjoying this technical stuff.  Let me know if anything is unclear, and I’ll be glad to try to illuminate it further.  As always, thanks for reading my work, and please share it with a friend if you have a chance.

Originally posted at One Man Football

1.  I’m not in the arguing business, I’m in the saying what I think business.
2.  I get my information from my eyes.

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