Breaking down the Defense

Recent news also states that the Green Bay Packers, (and several other teams in the NFC North) are going to be switching to predominately a 3-4 base defensive formation, over the more-prevalent t 4-3 (the Bears love it). In response to a conversation I had recently about defensive strategies, today, the Second and One Playbook, after much perusing the vast web of football knowledge on the Internets - attempts to demystify the 3-4 defensive formation. This is my first attempt at a full "Playbook" entry.

First, a bit about the numbers. In these formations, the first number indicates the number of linemen (not DBs/secondary), whereas the second indicates the number of linebackers. It's not like "you run the 3-4 when they're actually 3rd and 4, or when your record is 3-4," although that logic is certainly more amusing. By convention, then, the 4-3 uses four linemen, and the 5-2 uses five linemen. 

Obviously, then, the front seven for the 3-4 uses three linemen (two ends and a nose tackle; the former typically line up across from the guards, and the latter lines up across from the center*), and four linebackers, two inside (or middle, whatever you'd like to call them) LBs, and two outside LBs. The rest of the eleven, of course, consists of the free safety, the strong safety, and the two cornerbacks. 

The job of the linemen, as is the job for most linemen, is to block and plug gaps to prevent any sort of a run game from opening up.

There are typically many uses for the four linebackers. They're already set back for pass coverage, but for example, in a standard 4-man rush (such as those seen in the 4-3), the D-line normally takes this job, whereas things are slightly more ambiguous for the 3-4. Often, if fast enough, one of the linebackers stars as the 4th man (call it a pseudo 4-3). However, in theory, anyone in the secondary could also come out of the ether on the rush, which really serves to confuse the offense's read of the D on pass plays. 

One of the problems with the 3-4, as can be implied from lack of personnel on the line, is that the 3-4 can be swamped by all of the blocking going on up front, often leading to breakout runs, overstimulated and frustrated defensive ends, and broken remotes/TVs/coffee tables/egos on the part of the fans.

Cornerbacks: Like receivers, but with more hand-waving: the secondary can do anything, really, depending on the particular scheme devised. Cornerbacks are generally thought of as the ones who attempt to mirror receivers, leaping in front of them, and breaking up the pass on the intermediate-length sort of routes - which isn't far off from the truth. A friend of mine has the staunch opinion that receivers who are too jumpy or drop too many balls should simply be sent out to play cornerback for a while. 

The free safety (FS) usually serves to jog around downfield and attempt to get in the way of any deep balls that may sail out. The strong safety (SS) stays closer to the line, and, in a pinch, can participate in those "46" and "eight-men-in-the-box" formations, which, in my opinion, are effective if not used too often; the over-boxed defense is a conditioned team with absolutely zero pass coverage, especially if the secondary is weak and or slow (I like to call these sorts of secondaries "tertiaries.")

So, for the more visually-inclined, to the left is the Second and One Whiteboard O' Wisdom, where I have depicted a typical 3-4 formation. I have the linebacker on the line on the strong side. 

And that's all for this edition; Defensive Coordinator MC has work to do elsewhere. Remember kids: if you keep dropping balls, wear a cup.

EDIT: I'm not sure why my strong-side receiver is a little "O" in the above diagram. Pretend it's Steve Smith or one of those little 5'9" receivers to humor me.

*Somebody once told me that the best way to find someone (especially a female) who doesn't understand football is to simply ask "what do you call the person who snaps the ball?" If they say something like "uh...the person who snaps the ball?!" your question is answered. Preferably, this question best follows "what do you call the person who punts" or any of these other "who's buried in Grant's tomb"-style of inquiries.