I may lack some of the technical jargon for this discussion, but I have a pretty good handle on the physics of movement, and this is something that has been bothering me since the start of the season.
Some people do not like the Cover 2 zone defense we have been playing. Some people have been criticizing the frequency with which we blitz. Or the logic behind our occasional 3-man rushes. My thoughts on these topics vary. I may not like these elements, but I can live with them. But I have a very simple, yet influential problem with our base defense. I do not like the way we line up.
This is our base defensive formation. I call this 4-3 "stacked", where all three linebackers are standing in a row in the middle of the formation. It is a very common defense. I DO NOT LIKE IT IN GENERAL. I HATE IT FOR THE GIANTS.
In my opinion, this does not work with either modern zone and second-level blocking, or with the Giants personnel. In modern run-blocking schemes, offensive linemen are assigned to block linebackers, either as a primary duty, or more likely after releasing off a defensive lineman. This defensive alignment allows for a single offensive lineman to block two linebackers. How? If the line of scrimmage is not pushed back, the middle linebacker just needs to be held up or pushed to one side on inside runs to wall off one of the outside linebackers. This linebacker is standing rather flatfooted off the snap, waiting because the play is coming near him. More than likely he is just shuffling his feet. He's suddenly surrounded by big, round bodies that weigh more than him. The running back is hitting the hole with some speed. Can the outside linebacker tiptoe through a gap without getting pushed around? Can he suddenly accelerate to force himself through a gap, get push on the pile, or catch the running back as he passes the middle linebacker? All difficult tasks. There are too many bodies in the way.
The flatfooted issue also affect outside runs. Before the running back gets the handoff, the linebackers are trying to read the play. But it could go inside, it could go outside. So they are shuffling their feet again. The running back is going to get the ball and is going to be able to instantly accelerate or cut and accelerate. He is probably faster than the linebackers. He is almost definitely quicker in change of direction than the linebackers. He knows where the play is designed to go. If it is going out wide, it is a quick foot plant while already moving forward, and go. The linebacker is in the midst of his foot shuffle. He must now plant and accelerate. He was only lined up three feet outside of the QB at the snap. Is the linebacker going to beat the running back to the sideline? No. I take you to Lynch's big outside run to the right last week. Jacquian Williams was the linebacker on that side. At the snap, he took two light steps forward. Those two steps took him completely out of the play. By the time he turned his hips to run for the sideline, the play was by him. Many of you did not notice this because he was nowhere near the action. And he is our fastest linebacker.
This is the 4-3 formation I would prefer:
From Wikipedia, search topic: formation (American football)
I will call this the 4-3 "split". The linebackers start out wide and closer to the line of scrimmage. The WILL is going to have empty space in front of him, the SAM will likely have a tight end. At the snap, if they make a run read they are free to try and come upfield to prevent the outside run. They are in a position where they can beat the running back to the outside spot. Force the run inside to your tacklers. If the run goes the other direction, they can pursue from the backside to try and eliminate slower-developing cutbacks. On runs up the middle, they will be running into the play from the side. Harder to account for with blocking assignments. They are coming with speed and force, giving them an advantage if they have to go through someone or squeeze through a gap. The speed is also an advantage with making the tackle.
If you watch the successful runs of McCoy, Wells, and Lynch against us, you will see that the majority of big runs were to the outside, and rarely were linebackers in the play. The only time Arrington gained yardage against us was on the sideline. Everyone recalls Kiwi running by Wells on the goal line; what made it memorable was that it was the only time someone other than Webster was on the edge. McCoy was making cuts out in the flat. But he had room to make these cuts, and there was space for him to run through. It was not our linebackers out there forcing the cuts, it was Rolle and the other defensive backs.
Think of what we are asking Boley, Kiwanuka, and Greg Jones to do. None of these guys are sprinters. They are probably slower than the average NFL player at their position. Yet we are asking them to cover large sections of the field. We are asking inexperienced players to make quick reads to get into the right position. Meanwhile, the strength of this team is supposed to be the defensive line. We have plus run stoppers at defensive end in JPP and Tuck, and we have big run-stuffers at defensive tackle. We should be directing the running backs into them, not away from them. We should be playing to our strengths. But our formation at the snap does not allow us to accomplish this goal.
I could also get into the proven failure of one defender up, two defenders back when the offense puts three receivers on one side, but that is for a different day.