Why a 3-4 Defense Doesn't Work

The 3-4 defense does work very well if the defensive coordinator knows how to run it, but very few do, and as a result the 3-4 is very seldom particularly successful.

When the San Diego Chargers first switched to the 3-4 it was under defensive coordinator Wade Philips, who knows very well how to run that defense. He may be the best coach ever to run that particular scheme, and the Chargers were very successful with it for quite a while. Then he left, and none of his replacements have been able to provide the Chargers with a reliable defense using that pattern.

There was an article in the Detroit Free Press which posited that the Pro Bowl needed to change the way it selected outside linebackers because of teams which used the 4-3 defense, arguing that outside linebackers in the 4-3 did not make as many quarterback sacks as linebackers in the 3-4 and were therefor under-represented in the Pro Bowl. That was evidence, to me, that defensive coaches are not using the 3-4 properly.

Proper use of the 3-4 requires that all four linebackers play as linebackers. That means they are assigned as “head hunters,” assigned to cover a portion of the field with responsibility for defense against both run and pass. You do not merely treat the outside linebackers as nothing more than linemen who are standing up and use them as quarterback rushers. Doing that negates the advantage of the 3-4 in two ways.

First is that you no longer have four linebackers, you effectively have two linebackers and five down linemen and are actually using a 5-2 defense. You now have only 2-1/2 “head hunters” in the defensive backfield on each play because one outside linebacker is rushing the quarterback and the other one is a pass rusher who is wandering around back there wondering what the hell is going on.

You have also told the opponent where the pass rush in coming from. A major advantage of the 3-4 is that the opponent knows that a fourth player will be coming on the pass rush, but he doesn’t know where than fourth man will be coming from. It might be an outside linebacker, but it also might be an inside linebacker, or it might be a safety, or it might even be a cornerback. That makes blocking assignments very difficult for an offense. If he knows that the fourth man is going to be an outside linebacker, pass blocking becomes a hell of a lot easier.

Finally, a 3-4 defense has to be aggressive, has to attack the opponent. In the 4-3 defense you have four down linemen protecting three linebackers, preventing the offensive blockers from getting to and disabling the linebackers. In a 3-4 the linebackers are “naked.” You have only three linemen covering four linebackers, and blockers can easily get to and disable a slow moving or stationary linebacker. In a 3-4 defense the linebackers must be in motion the moment that the ball is snapped; if he remains static even for a second an offensive player can get to him and take him out. Too few defensive coaches realize that.

Announcers go crazy about the “last minute winning drives,” giving credit to quarterbacks and offensive players, but in most of the ones that I have watched, the real cause of that drive was a defense that could not finish off the opponent, and it was almost always a 3-4 defense that did not attack.