AbsolutAnalysis - "Defensive Fronts, Part Three"

In Part Three of this series, Seahawks.NET Xs and Os Guru Matt Lathrop concludes his detailed look at defensive fronts and assignments.

Welcome to the final installment of the Defensive Fronts series. You can find Part One here, and Part Two here. This week we will finish up by taking a look at the 46 Bear defense.

The purpose of these articles is twofold: to present the readers specific fronts so you can understand the game to a more in-depth degree, while also presenting some fundamentals of every defensive scheme. For example, you will often read how a DL must "pinch down the play side gap." This is never scheme-specific, as it is a very important skill for defensive players regardless of the front. They must often use not only their own bodies to make the play, but the bodies and lack of leverage of the offensive player they have engaged. So as you read this column, recognize these concepts and understand that they are universal fundamentals, and not scheme-specific. The fronts, assignments, and responsibilities you read in this column are specific, and it's important to understand the difference, while maximizing the information while reading articles like mine.

Ok, enough of that, sorry if you had a high school flashback! As I said in Part One, this is a scheme that isn't run in today's NFL, but has developed "child fronts," meaning there are versions adapted from the 46. Let's take a look at the alignment of a 46.

46 Defense

As you can see, the primary difference between this front and what we've seen so far is that the 46 is an eight-man front, rather than a seven-man as are the 4-3 and 3-4. Although it looks as though the entire DL is shifted heavily to the weak side, the only significant changes from a standard 4 man line are the NT and SDE. Instead of shading the center, the NT lines up in a middle 0, directly head up on the center. The SDE moves inside, where you would expect to see a DT. The DT and WDE are lined up just as you'd see them in an Under Front. The biggest change involve the Linebackers. As you can tell, Mike is rotated heavily to the strong side, playing a 5 alignment over the tackle – but at the second level, of course. The OLB is in an alignment similar to an Under Front, but is not directly over the TE. He plays outside and just off the line, acting as primary force on outside runs, as you will see below. The 5th man on the line of scrimmage is another LB, who is in an 8 alignment, head up over the TE. He must keep the TE from releasing to down block the Mike, while being able to maintain both C and D gaps. In the diagram below, you can see that he has a lot of responsibility on plays run to his side. Finally, the Strong Safety is moved up into the box, providing run support to the defense while occupying the area vacated by the linebackers who have rotated to the strong side.

46 vs. Weak Side Run

As you can imagine, this defense was designed to be very stout versus the run. It might seem like a no-brainer that an eight-man front would be successful against a run play, but you have to remember that each player has their own unique responsibility, and the ability of the entire defense relies on each player executing properly and effectively. If one man blows his assignment, it makes another player's assignment that much harder, which leads to the same for another, and on and on…On paper, the play side assignments are bit more complex, but can easily become second nature for the players through repetition. On the field, they would appear to make plenty of sense.

On a weak side run, the DE's duty depends on what the Tackle does. If the Tackle "base blocks" (man blocking, pushing him out) the DE out, then the DE must hold the Tackle and pinch the C gap to try and squeeze the hole down. Otherwise, he must two-gap the Tackle and maintain the RB's depth on wide plays while stringing it out and waiting for backside help. The SS works as a sort of tandem with the DE. If the Tackle base blocks the DE, then the SS must attack the hole, while using his inside shoulder take on traffic. He uses his inside shoulder, because that forces the play inside, where his linebackers are waiting. If he uses his outside shoulder, then he places his own body inside, and allows a seam to the outside, where the only defense left is the FS and a prayer for a well placed divot in the field.

The NT and DT have their respective play side gaps; weak A for the NT and weak B for the DT on this play. The Mike is responsible for covering the strong side A gap on his way to the ball, while the strong DE controls B gap while pinching down the strong A, to help free up the Mike to make a play. The linebacker over the TE has strong C gap while the OLB has contain and chase while protecting against reverse and counter.

46 vs. Strong Side Run

Things change up just a bit on a strong side run. As you can see, the defensive players on the strong side outnumber the gaps by one, just as they do on the weak side. However, the responsibilities aren't quite as simple as above. The back side, however, is fairly basic, with the NT, DT and SS all taking their respective play side gaps, with the DE trailing while containing reverse and counter. Front side, or play side, is another story. The DE has the B gap that he must penetrate in order to disrupt the play and make Mikes job much easier.

The most difficult part of Mike's jobs here is to determine which gap the play is designed to attack, in about .2 seconds. If the ball is coming to the strong A or B gap, he is responsible for the strong A gap, but if the ball is run wide, he needs to control both C and D gaps. The LB over the TE has a bit easier job, although the same concept applies. To start, he must two gap the TE and be able to control either C or D gaps. On an inside run, he must remove the TE and maintain the C gap, but on an off TE run he will attack the D gap, or act as cutback support on a pitchout. The OLB job is to act as primary force on a wide run, and attack the play from behind on an inside run.

Well, that does it for the Defensive Fronts series. I hope you not only learned how to identify fronts and responsibilities during a game, but picked up some basic concepts for playing defense and understanding how and why schemes work in general. The 46 especially displays the need for individuals capable of constantly maintaining their assignment in any defensive scheme, because a small breakdown in the scheme can lead to a total collapse of a play, which forces a defense to rely on secondary support and allows the offense to rack up yards. I don't know what you'll see next time, so please email me with questions, ideas, and comments!

For past articles, check out the AbsolutAnalysis Column Archive.

Matt Lathrop, .NET's "Xs and Os Guru", writes "AbsolutAnalysis" every Wednesday. Feel free to contact him at mattl@seahawks.net.


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