What are the personnel requirements for the 3-4 defense
The front 7 players in the 3-4 D are significantly different from their counterparts in the 4-3. In a nutshell, the DL in the 3-4 are bigger than the DL in the 4-3. The 3-4 OLBs are bigger than 4-3 OLBs because they have to match up against OTs.
* 3-4 NT is the toughest position to fill. The NT is head-up on the OC and is responsible for defending both A gaps in the running game. He faces constant double-teams and takes a pounding. He must have size, mental and physical toughness, stamina, durability, lateral quickness, and good technique in terms of playing with leverage. If the NT can not hold his ground, the defense is very vulnerable to runs between the tackles. The prototypical 3-4 NT is the Raiders' Ted Washington, who is a massive 6-5 365. Washington was the key to the Patriots win over the Panthers in the 2004 Super Bowl. Stephen Davis ran for a meager 19 yards on his first 9 carries, because Washington effectively stuffed the middle of the line. Other quality NTs include the Steelers' Casey Hampton (6-1 320) and the Chargers' Jamal Williams (6-2 348)
* 3-4 OLBs are the playmakers of the D. They get the glory of picking up sacks on the QB. They must have strong pass rush skills and be able to drop into coverage. If the 3-4 OLBs are unable to consistently apply pressure on the QB, the D is very vulnerable in the passing game. They tend to weigh around 245-270, and many are former 4-3 DE/OLB "tweeners". Many 4-3 DEs are not suited to playing 3-4 OLB because they lack the ability to play in space. The more agile 4-3 RDEs, such as the Jets' John Abraham (6-4 256), are able to play both 4-3 DE and 3-4 OLB. Many 4-3 OLBs are not suited to playing 3-4 OLB because they lack the pass rush skills and the ability to go toe-to-toe with an OT. Examples of solid 3-4 OLBs are the Patriots' Willie McGinest (6-5 270) and the Steelers' Joey Porter (6-2 248)
* 3-4 DEs tend to weigh around 290-310, and many are former 4-3 DT/DE "tweeners". They must be able to play the run well. The 3-4 DE is responsible for the B and C gaps in the running game and lines up in the 5-technique position, so he is head-up on the OT. It's tough for a 3-4 DE to pick up as many sacks as a 4-3 DE, because a 3-4 DE doesn't have the freedom to go willy nilly upfield. He has to protect the LBs in order for the 3-4 to work. Panthers' 4-3 DE Julius Peppers said that he didn't like playing 3-4 DE, because he felt like he was essentially a DT. Unlike Peppers (6-6 290), most 4-3 DEs are not suited to playing 3-4 DE, because they lack the size and ability to hold up against the run. Examples of solid 3-4 DEs are the Patriots' Richard Seymour (6-6 310), the Steelers' Aaron Smith (6-5 300), and the Raiders' Bobby Hamilton (6-5 285)
* 3-4 ILBs must be stout in run support. Because there are only 3 DL to match up against 5 OL, they must be able to stack and shed an unblocked offensive lineman in the running game. How hard is it to play 3-4 ILB? Check out this telling quote by All-Pro Ray Lewis, who is glad to be finished playing 3-4 ILB (the Ravens are switching from the 3-4 to the 4-3 and 46 for the 2005 season):
"We're in the 46 defense now, and finally, finally again, I get to play football," said Lewis. "My job is not to take on offensive linemen, but to make running backs not want to play against me"
Examples of solid 3-4 ILBs are the former Ravens' Ed Hartwell (6-1 250) and the Raiders' Danny Clark (6-2 245)