Id like to get into the nuts and bolts of Mike Nolan's defense and would like to dedicate a thread to the subject. How do the roles of the front seven players change when running a one-gap 3-4 vs a traditional 3-4? I understand that the Linemen will play a more attacking style of defense, but how does that impact the linebackers? Also, wont we be at a disadvantage in the run game with only 3 down linemen and noone blocking for the LB's? What are the disadvantages of this alignment? Where might we be exposed along the front 7? Thanks
I posted this article in another thread, but its so good that its worth re-posting (in fact -- it should probably be a sticky on these forums). Regardless, it provides an excellent breakdown on variations of NFL defenses. Its lengthy, but well worth the read (probably the best football related article I've ever read). http://subscribers.footballguys.com/2009/09bramel_idpguide.php
Thanks man. I actually printed this out this morning after you posted it. Will make for some good bathroom read this weekend.
Thanks for the read. FYI I think this refers more to a classic 3-4 with the NT clogging multiple gaps.
A one-gap defense basically means that defensive linemen are responsible for penetrating a single gap, simply. They are typically lining up over the gap they are playing- Generally the weakside DE is playing a 3-technique on the side with no TE, the NT plays a 1-technique on the strong side, and the strongside DE plays a variable position anywhere from a 3-technique to outside of the offensive tackle. A two-gap defense means the defensive linemen on running plays are responsible for reading where the play is going, and then filling that gap. They typically line up directly over the linemen(The DEs line up directly over the tackles, and the NT directly over Center), and say if the run goes towards the offensives right side(Behind the TE), for example, the strongside DE will fill the gap between TE/RT, the NT between C/RG, the weakside DE between LG/LT. Typically, you need bigger, stronger players to play 2-gap. They've essentially got to take on a block and shed it, and consequently you want guys with strength to overpower offensive linemen, and the reach to engage them at an advantage. 1-gap is typically more variable personnel wise. The three defensive line positions are pretty close in positioning and responsibility to the two DTs and strongside DE in a 1-gap 4-3 defense(Which is probably the predominant NFL defense and has been for a while). You can get away with having a 300-pound converted DE like Jay Ratliff in a 1-gap 3-4, but you can also have a 350+ pound behemoth in the role as well. 1-gap responsibility isn't inherently an aggressive, attacking responsibility. There's more than one way to play it. If you've got a 350 pound run stuffer, they're still going to consistently draw a double team, and they'll probably fairly often go through that same gap they are sitting over. A guy like Jay Ratliff, and theoretically Randy Starks can play it a little bit more interestingly. Instead of reliably going through that same gap, he's more likely to stunt and do other things that free him up to get into the backfield. Linebacker wise, I don't believe there is inherently any difference from an overall scheme wise, I think it comes down to a coaches personnel preferences. I don't know either 1-gap or 2-gap fronts "protect" linebackers better- Good linemen who draw attention from the linebackers protect linebackers better. In theory, it's said that 2-gap fronts require bigger linebackers, with the explanation that the Guards are sitting uncovered looking right at the linemen on the second level, but I don't really buy it. Zach Thomas had arguably his best season in Saban's defense, where Kevin Carter and Keith Traylor formed a 2-gap "bubble" infront of Zach identical to what he'd have in a 3-4.
