Danno

In contrast to the true 2-gap 3-4, there’s no clear “bubble” in a 1-gap front. The strongside end slides down in the guard-tackle gap and the nose tackle slants to the weakside center-guard gap. The weakside end may or may not be head-up on the tackle, sometimes aligning in a 5-technique. Moving the defensive lineman just a few inches changes the philosophy entirely. The diagram above shows an under-shifted 3-4, but over-shifted 3-4 fronts are also common.

It’s clear that the two inside linebackers can be, if the linemen are disruptive at all, better protected from the blocks of interior linemen. You can see the lines of attack for a delayed ILB blitz or how each OLB might get a jump by shifting one defensive end to the outside of an offensive tackle.

The under-shifted 3-4 front, with or without a 2-gap end, is just one of many potential variations a coordinator may align for his front seven. In fact, a coach influenced by both flavors of the 3-4 might be tempted to meld both concepts with traditional 4-3 ideas and create a monster playbook with more than 50 fronts. And pull it off with amazing success.