Basics of the 4-3 Defense

[osugrad21]

Basics of the 4-3 Defense
written by osugrad21 graphics by Clarity (7/1/2004)

The following is a very basic breakdown of the positions and responsibilities in a base 4-3 Defense. Terminology for the positions may vary amongst different programs but the basic premise and philosophy of the scheme remains true.



Technique Breakdown--

0--head up on the center
1--inside eye of guard
2--head up on guard
3--outside eye of guard
4--inside eye of tackle
5--head up on tackle
6--outside eye of tackle
7--inside eye of tight end
8--head up on tight end
9--outside eye of tight end

NoseGuard (NG)-- The job of the NG is to stuff the A gap between the center and guard. This position is usually, at least traditionally, secured by a heavy, low-centered player who can force a double team block from the guard and center. The NG's job is not to blast into the backfield but instead to engage and occupy the lineman to keep the Mike LB free to make the play. This position is not a glamor job but is very important to the success of the unit. If the NG is unable to command a double team, the guard is free to move onto the second level and occupy the LB.

Defensive Tackle or 3 Technique (DT/3)-- The Defensive Tackle is responsible for the B gap. The Defensive Tackle is responsible for the B gap only but is also asked to help control the strong side A gap by reading the block of the guard. The Defensive Tackle is usually the more athletic of the interior lineman as his quickness is a key attribute in playing the A and B gaps.

Strong Side Defensive End (SDE)-- The Strong Side Defensive End must be a stud. His alignment is a 9 technique or outside eye of the Tight End. However, he must control the C gap which means he must fight through the turn-out block of the TE to control that gap. He is trying to force everything back inside by holding containment. If an option comes to his side, he must annihilate the QB and force the pitch. This position requires an aggressive, athletic player.

Quick Defensive End (QDE)-- The Quick Defensive End plays the weakside in a 6 technique on the outside eye of the tackle. Many times, the QDE will cock his stance at an angle to engage the tackle while still holding outside leverage. The QDE is responsible for outside containment to his his side and immediate backfield pressure.

Strong Side Linebacker (SAM)-- SAM is responsible for the strong side C gap along with the SDE. he makes sure that nothing can be bounced outside if the hole is plugged. He must also engage the Tight End to avoid being sealed off to the inside. SAM must be a physical, strong, quick player able to mix it up but still contain the outside speed.

Weak Side Linebacker (WILL)-- WILL is responsible for the backside B gap and also outside containment to his side. Once he reads flow away, the play going away from him, he immediately moves laterally to the backside B gap to stuff any counter action. If the counter is not happening, the WILL is free to pursue the ball and rack up the tackles. A ballhawk with quick reading ability and a relentless motor is ideal in this position.

Middle Linebacker (MIKE)-- The Mike Linebacker is responsible for all front seven check offs. He must be aware of all offensive sets and the corresponding defensive audibles in order to adjust properly. He is responsible for the playside A gap and also the backside B gap. When engaged, the MIKE must meet the blocker head on in the gap and never give a side or any leverage to create a seam for the back. Therefore, a physical, strong, and aggressive player with the brains to understand the defensive philosophy is required to play the MIKE.

The Secondary (CB, CB, $$, FS)-- The basics of the secondary were covered in an earlier blog. Their responsibilities will change with the coverage called. The above diagram is of a Cover Three model. Therefore, the Strong Safety ($$) is moved to 7 yards off of the LOS on the strong side. In this coverage he will supply strong run support and help on outside containment issues while also holding responsibility for the pitchman on the option. The secondary will always play pass first but any run support provided is always helpful. The corners especially must help with outside containment issues and force any breakouts back to the inside of the field where the pursuit can help.

[BuckNutty]

Good stuff, 21.

[Buckskin86]

Grad- great job!!

[wdg01]

Very nice 21...I learn something new here every day

[Buckeyejeff]

Very informative. By your breakdown I assume that Simon Frasier is considered a quick defensive end, am I right?

[osugrad21]

Jeff, I watched the 02 Fiesta to make sure and I don't believe OSU declares a steady SDE or QDE. It is all according to the formation and call.

[BB73]

Good stuff, grad. I'm just getting to the blogs here and I definitely need to keep checking them out.

bb73

[Buckeye86]

So, this is quite the bump, but I was wondering if anyone has updated information on the schemes that the OSU defense employs. For instance, is the LEO position just an updated version of the Quick Defensive End? what type of dynamics does the Star position bring to the defense (other than the obvious advantage it gives us covering against the spread)? and are the differences between boundary corner and field corner as straight forward as it sounds?

If there is some other place I can find this information at feel free to call me stupid and direct me there, but I searched and this thread was the best place I could come up with to put these questions.

Thanks.