How your Defensive Line attacks and defeats their blockers is crucial to defending the Inside Zone. Regardless of what front you choose, the Linebackers are going to be expected to make a majority of the tackles.
Our Linebackers in the 4-2-5 Defense are going to use the running backs as their primary key. Backfield flow normally tell them what play they are seeing. Split flow is common in Inside Zone schemes, with the Fullback kicking out the back side Defensive End (or the QB reading him in Zone Read), so we have to work that look during the week in practice.
He’ll need to pick up the movement of the Offensive Line opposite the steps of the back. The path of the Offensive Line should match the path of the back. If he sees anything out of place, like pullers, they will take him to the play.
The key is for the Linebackers to be patient with their feet while their eyes recognize the play. Once they recognize the play, they need to be extremely fast and aggressive in their attack. As long as the Defensive Line is doing their job, occupying the Defensive Line and commanding double teams, we can take our time to read the play.
If the backers are sitting back and letting linemen work up to them, they will be unable to stop the play. As soon as they diagnose the play, they need to be fast to their gap responsibility. It has to become reaction.
In our defense, no matter what front, the Inside Linebackers are spill players. So when they attack their gap, they need to take away the inside half of the gap. He should be attacking the Offensive Lineman on the inside half of his gap. Linebackers cannot run around blocks.
Linebackers have to be smart, too. They cannot fill a gap just because it’s their gap. If the movement of the Defensive Line or the blocking scheme of the Offense closes up his gap, he should be scraping to fit the first open window he sees. Linebackers have to make the Defensive Linemen right, and Safeties have to make the Linebackers right.
The backside linebacker will be crucial in stopping the play. We teach him to shuffle at the 4-Yard Fight Line, a great concept I got from Ricky Coon when I was at Ellsworth College. The backside backer is going to take his read steps, and on reading flow away, shuffle at a depth of 4 yards off the ball, not passing the center, until the ball declares to play side. If he sees the cutback off the Inside Zone by the Tailback, he’s in position to fill downhill now, shutting off the cutback lane.
If your backside backer is ever having to come BACK for the cut-back, he’s out of position. At the same time, if your linemen are giving you any help at all, he can still get over the top to help on the play side. The 4-Yard Fight Line teaches him to stay out of the mess up front while keeping his eyes up for oncoming blockers.
The more dominant and demanding the Defensive Line is, the longer it takes for Offensive Linemen to work up to the backers. The DL plays a huge role in stopping the play and making life simple for the backers. They can grab those guys and hold them back.
If you have trouble with the Inside Zone attacking your weak side, you can adjust your 4-3 Defense or 4-2-5 Defense to an Under Front. We play the weak side Tackle in a 3-Technique, outside shade of the Guard. The strong tackle plays a 1-Technique, shaded strong on the Center (or a 2i, inside shade of the Guard).
That adjustment will help if you are using a smaller player for your weak side backer.