What is 3-4 Defense in American Football ? How Does it work?

What exactly is a 3-4 defense? and how does it work? Which are the players involved in the 3-4 defense? and why should a team go for it?

If you are looking for the answers to these questions, then this article is definitely for you. 

A 3-4 defense play is a very common defense alignment in American football. It consists of three down linemen and four linebackers. Of the three defensive linemen, two are on the defensive end and one is assigned the nose tackle, subsequently, of four linebackers, two are inside linebackers and two outside. So this constitutes the player line-up for a 3-4 defense. 

One of the biggest differences between the linemen in a 3-4 defense and a 4 3 defense is that the linemen in the 3-4 defense are not placed to use speed. They do not have to penetrate the gaps of the line, rather than in the 3-4 defense line up, the most important factor is the size and length of the defensive line, as well as the ability to occupy the space or the offensive linemen. 

This affords a special advantage to the players, it frees up the inside LBs and gives them an opportunity to run to the football. Meanwhile, the outside LBs, who occupy the premium football position in the 3-4 defense play, make plays as edge defenders out of a stand-up, two-point stance. 

The 3-4 defense is also called the ‘base defense’ as it is the defense used by default on the 1st and 2nd downs, also called the base downs. Some defenses prefer to use a 4-3 defense. In earlier years, all teams used to run a ‘base’ formation on most of their plays. Almost all defenses would have a base formation including one of the two: 

Either they would have Four down linemen and three linebackers, or Five down linemen and two linebackers. 

But in the early 21st  century, the teams switched to the base defense system which we call the 3-4 defense system.  This was opted by teams in American football because firstly it confused the opponent offense and always kept it on its feet for anticipating the next move of the defense. Another reason why the need to change the existing play was that the base system being used got flipped on its head often during the 1990s and 2000s. 

Generally in the case of the old school 3-4 defense, the three defensive linemen use a “2-gap” technique. However, there are variations of the 3-4 technique that use a 1 gap technique as well. There are different kinds of 3-4 fronts that players use.

  • Okie front
    • Eagle Front
    • Under Front

Types of 3-4 fronts 

  1. Okie Front: 

The Okie front is a traditional form of 3-4 defense that you can see teams like Patriots using. herein, both the defensive ends and the nose tackle use a 2-gap technique, that is to say, they play two gaps in the run front. 


3-4 okie front

Inside the lineup, the two linebackers (Mike/Jack) should have the size to be able to get downhill and fill in both the A/B gaps versus base runs. This needs to be done while the two outside linebackers (Sam/Will) play contain (or force) and cutback/boot.

The defensive ends are set aligned over the offensive tackles in 5 -technique. They are responsible for playing the 2 gaps in the B C gap. While the nose tackle (N) is given the responsibility to play both a-gaps, they are aligned head-up versus the center.

At the second level, the inside linebackers Mike (M) and Jack (J), align over the uncovered offensive lineman, also called the “bubbles”. They, then, fill in the A/B gaps. On the edge, the outside linebacker Sam (S) is positioned in a 7-technique outside the tight end (Y). The other outside linebacker, Will (W) is in a 6-technique.

The two inside linebackers  (Mike/Jack) are left-aligned over the guards. They fill downhill versus the base run game, which may include Lead Closed, Power O, Counter OF, and so on, to the A/B gap. 

In order to take the pressure off the inside linebackers, who are left unprotected and unguarded by both guards, the defense may use stunts or it may blitz. The Defense might end slant, X stunt with the outside linebackers. 

The advantage that a 3-4 Okie provides moves past the run fits. By using the 5 technique, the outside linebacker, Sam, is able to cover down to the second receiver. This gives the defense a great advantage in pass distribution while they are able to keep the box intact. 

  1. Eagle Front 3-4 defense :

The Eagle Front is illustrated by teams like the Steelers, Packers, and Redskins. It looks very similar to the base 3-4 front with a few subtle variations in the front. In an Eagle 3-4, a linebacker takes the position in place of the player who, in a traditional 3-4 front, is placed at the defensive tackle or nose tackle position. This turns the defense into a 3-4 front with 5 linebackers. 

The Eagle front entails the use of a 1 gap technique along with the Sam linebacker using the 2 gap technique. This technique is used over the tight end to the closed side of the formation.

3-4 Eagle front

Both the defensive ends (E) align in a “4i” technique on the inside shoulder of the tackle. They play the B-gap. Meanwhile, the nose tackle (N) works to the A-gap also called the “front side of flow”

Because the defensive ends use  “4i” alignment to the closed (strong) side of the formation, the linebacker Sam (S) is made to play the 2- gap technique aligned in a 6 over the tight end (Y). The Sam is supposed to press/flatten the tight end on the stretch play and they also have to fill in the C-gap with the end now occupying the B-gap.

At the second level, both the inside linebackers Mike (M) and Jack (J) play “A-gap to scrape” that is they attack A-gap or scrape versus flow. The other linebacker, Will (W) is made responsible for cutback/boot to the open side as a 6-technique.

  1. 3-4 Under Front 

The 3-4 under front was used by the Texans and defensive coordinator Wade Phillips during the 2013 season in Houston.

This is also a one-gap technique that is used to give protection to the closed-side defenders. The protection is afforded to them with the open-side Will linebacker and defensive end who are in a position to clean up as cutback players. 

3-4 Under Front 

The defense gets protection to the closed side with the nose tackle (N) in 1 technique placed on the outside shoulder of the center. This position is the same as in the case of 4-3 under the front. To further the protection, the defensive end (E) is placed in a 5/6-technique and the Sam (S) linebacker is aligned in a 7 technique outside of the tight end (Y). 

The defense is ironclad with Mike filling the B-gap. Thus the defense has every gap covered to the closed side of the formation. 

The Will linebacker plays the cutback with 6 techniques towards the open side. The Defensive ends (E) are aligned in one of the two: 2-technique or the 3 technique. Here the defense has two options: 

  1. It can place the Jack filling into the A-gap. For this, the defense aligns the end in a 3 technique. 
  2. The defense can use a 2 technique to bump the end down. Using the second option the end is able to 2-gap the guard, while the jack is on a fill or scrape. 

Personals in 3-4 defense line up 

In order to run the perfect 3-4 line, you need to have the proper personnel. There are a number of responsibilities that the players have in a 3-4 defense front. And you have to be aware of all of these when trying to create any one of the 3-4 defense fronts. 

Here is a description of how you can run a perfect 3-4 defense. 

  1. Nose: 

In the 3-4 alignment, the nose tackle or the nose guard is usually a big, bulky player placed in the middle. The player is the lone defensive tackle for the lineup. The nose tackle is like the anchor in the 3-4 defense. This means that the nose tackle has to have size, strength, and core power. So that they can command double-teams. They also have to keep the interior guards off the inside linebackers. Thus, the player who is placed at this spot has to be quick off the ball and play with leverage. 

The nose tackle or nose guard are placed either in the 0 technique or in the 1 technique. The 0 tech, which lines up across the football from the center, is much more frequent than the 1 tech. The 1 technique lines up between the center and the guard. 

  1. Defensive ends: 

The defensive ends also play a very important role in the 3-4 defense. They are entrusted with the same responsibility as the nose tackle, the only difference is that the defensive ends are concerned with the Tackles instead of the Centre. 

In a traditional, authentic 3-4 defense, the defensive ends are positioned in the 4 technique, placing them directly over the offensive tackle. Another common spot for the defensive ends to be placed in is the 5 tech. Other than the 5-tech, the DE can also be positioned at the 4i spot. Here the defensive ends are shaded slightly inside of the tackle. 

The responsibility of the defensive ends is to control the offensive tackle and draw double teams from the other blockers; it does not matter if the other blocker is a guard, tight end, or running back, the DE is responsible for them. 

Suppose in a football match the nose tackle is on the center and the guard is on one side, the offensive tackle is tailing the defensive end, and the OLB is approaching. Who do you think will stop the OLB from coming in?  And who would stop the ILB shooting through one of the remaining gaps? 

All of this falls on the defensive ends’ shoulders. The offensive tackle is generally the tallest player in the team, and this means that if a shorter player is placed as the defensive end, they would not be able to get around through the long arms of the OT. so the defender has to also be of tall stature with a lot of strength to push past the offensive tackle. 

Sam Linebackers :

A Sam linebacker is required to be a player with multi-faceted abilities. They need to not only be quick in movement but also have the strength required to fight off the blockers and get to the ball carrier. The player positioned as Sam is required to be quick so that they can get to the hole and seal off the running lanes. Another very important ability for Sam to possess is that they need to be flexible as Sam needs to turn the corner around the blocker. 

Sam usually plays a 6 tech role and is responsible for the C-gap. Sam is seen as the most important player in run defense. 

Jack Linebacker : 

Jack linebackers get their name from the phrase “Jack of all trades” and as the phrase goes, they also have to be good at multiple things in the game. While the primary responsibility they are entrusted with is rushing the quarterback, that is not all that they have to do in a 3-4 defense. A jack also has to fall back into the coverage and defend the run. They are supposed to be able to do almost everything from playing the run to dropping into coverage and rushing the passer. While in the 3-4 defense formation, the Jack Linebackers usually line up in a nine technique. 

Mike :

Mike linebacker is the quarterback of the defense. This means that they are responsible to make defensive audibles and line calls as well. In a 3-4 defense, Mike is supposed to be a smaller, faster player, as they are supposed to fight off fewer blocks. They can rely upon the linemen to control the counterpart in the offense team.

Mike in the 3-4 lineup is a 2-gap player. In a pass and play, they have a number of responsibilities like covering the tight end, covering the running back, and dropping into a short zone. 


Will linebacker is technically a Mike the only difference is that Will is a bit smaller, faster, and better in pass coverage. Both Mike and Will have to play the inner linebackers, however, their responsibilities may differ slightly to fit the differences in their skills. The ILBs could have even been interchangeable had it not been for Mike’s requirement to “quarterback” the defense.

The 3-4 is a flexible defense that affords a great advantage to the team. The advantage is even more apparent when it comes to rushing the quarterback and defending against the pass. The most beneficial thing about the 3-4 defense is that it confuses the opposing quarterbacks, who may find it tough to keep track of these roving linebackers who line up all over the place.