[raidersdiehard]

All this Glenn Dorsey/Sedrick Ellis talk had me questioning my knowledge of the 3-technique vs 4-technique vs 0-technique vs NT defensive tackles. After reading this I'm sure a lot more informed and wanted to show my finding to you guys. I've read elsewhere that Ellis is a 3-technique and somewhat better than Dorsey because of this...

Types of Tackles

The linemen on the offensive line up a few feet away from each other. This leaves gaps between the linemen. These gaps are both lettered and numbered, as shown below. The gap between the guard and tackle is called the B gap. If you are a defensive tackle lined up in the B gap, but shifted over a bit towards the guard, you're called a 3-technique. If you were lined up in the same gap but shifted over a couple feet to line up on the tackle's shoulder, you would be a 4-technique. If you line up directly facing the center, you're called a nose tackle or a 0-technique.

Nose tackles are two-gap players and are typically very big and very strong men. These guys have the responsibility of clogging up the entire center of the field, of keeping the center and at least one guard busy, and thereby protecting their middle linebacker. The nose tackle will also be responsible in passing plays to push the center back towards the quarterback so that the quarterback cannot step up in the pocket and evade the rush of the defensive ends. A good nose tackle can be hit simultaneously by 650 pounds of center and guard and will not budge as much as one inch.

Occasionally, a defensive scheme will ask both defensive tackles to essentially play as nose tackles, one trying to occupy both the center and a guard, and the other trying to occupy the opposite guard and the corresponding tackle. If successful, this leaves a tight end trying to block a defensive end on one side, and the other tackle left to block the other defensive end, leaving the responsibility to blocking the three linebackers, be it if they are blitzing a pass or preventing a run, to the running backs. This strategy requires two nose tackles who are very good at two-gap play, and two athletic ends who can beat a blocker to the outside for pass rush, but can be very effective if the talent is there. This style was the preferred defensive scheme of the 2000 Baltimore Ravens, a top-5 defensive team of all time and the best defense at stopping the run in the modern era.

A 3-technique tackle lines up between the offensive guard and tackle. A 3-technique tackle is supposed to run through his gap immediately. He is a 1-gap player. His job is not to block or get tied up in a block, but rather to be athletic and get himself into the offensive backfield and disrupt their plans. Because of this a 3-technique tackle is a lighter, more athletic guy than a nose tackle.

More info here...