"If you talk bout the 3-4, you must start with the linebackers."-Warren Sapp aka "the sapper," as in saps my energy trying to make sense of your analysis, making a fool of himself of NFL GameDay Morning last Sunday.
No you have to start with the nose tackle. Historically, the four person d-line lines up 2 on each side of the center, often with a strong and a weak defensive side corresponding to the weak and strong offensive side. If I am switching one on my defensive players from a 300+ pound tackle to a 220 or so pound linebacker, who is going to stop the run? The answer is that you need a strong nose tackle to stop the run between the guards. Essentially the nose is doing the work of at least 1.5 people depending on how much help he gets from the defensive ends. If you have the proper personnel with two strong ends and a great nose, then you can allow the extra linebacker to line up so now you have two line backers on each side. If the offense wants to run along the edges to either sideàtwo linebackers to get the stop. If you want to pass then you have two corners, two safeties to cover and four linebackers to either rush the qb from the outside for pressure, or drop back into pass protection. If the offense knew at the beginning that running between the tackles was an option due to the weak nose the entire 3-4 system would be futile.
One of the best descriptions about the switch from the 3-4 and the 4-3 comes from my friend Keith Hood who was actually hating on the Charges at the time. He liked to tell me that Shawne Merriman is a glorified defensive end. That is exactly right if you do not have a strong nose tackle to back you up. Ideed, the MOST important defensive player is the nose tackle.
Ironically, in the examples Sapp used you plainly see the nose tackle taking on 2 O-linemen for four straight running plays and gumming up the middle of the field. Sapp, you have no idea about how this works. But I already knew that when you signed with the raiders.