Ok, someone tell me about what you look for in the transition to 3-4 NT and 3-4 DE.
What are the conditions for a 4-3 DE to become a 3-4 DE.
What are the conditions for a 4-3 DT to become a 3-4 DE.
What are the conditions for a 4-3 DT to become a 3-4 NT?
3-4 linemen are generally bigger and stronger. In most 3-4 schemes, the linemen are in a read and react mode where their goal isn't to make tackles or get sacks but to disrupt the linemen and the blocking schemes to allow the linebackers to penetrate, make tackles, and get sacks.
The 3-4 NT should be a behemoth. His job is to be immovable. If two or three guys try to block him, he's got to hold his spot and not budge. He's supposed to clog up the middle. If the running back gets around him, his job is to fall on him and break him into little pieces. We don't really have one of these... except maybe Powe. He generally plays head up over the center although he may shade to one side or the other. The idea is that the center is vulnerable after making the snap and the other team needs to help him out with a guard to keep the NT from eating him alive. It helps if your NT has a very fast first step to really punish the center. Think: Vince Wilfork.
A 4-3 DT is a more agile guy than the 3-4 NT and usually smaller. Although he has to be able hold his own, in a lot of defenses, he's going to be asked to just play one gap. He's supposed to try to get penetration and force the other team to waste two blockers on him. Think: Earl Mitchell or Tommy Kelly.
A 3-4 DE is a lot like a 4-3 DT, big and strong but not as big as the NT and usually more agile. The 3-4 DE's job is to fire off the ball, engage his blocker, and then read whether he needs to shut down the lane to his right or left. 3-4 DEs are strong guys but since they're not generally shooting gaps, they don't have to be very fast. Think: Ty Warren, Stephen Bowen.
A 4-3 DE is usually faster and lighter than a 3-4 DE or a 4-3 DT. These are the guys that get the QB. Think: Julius Peppers, JJ Watt, Mario Williams.
So. For a 3-4 NT to transition to either a 4-3 DT or a 3-4 DE, they generally have to lose a lot of weight and work on their speed and quickness. For a 4-3 DT or 3-4 DE to transition to an NT, they generally have to gain a bunch of weight and strength.
At least, that's the way I've always looked at it. This is a simplified and quick version but I think the gist is there.
