The 3-4 defense dates all the way back to the 40’s when the Oklahoma Sooners started running it, and it is a very popular defense in the NFL today. Bill Belichick has ran it for most of his career on his way to five super bowl titles. I feel like it is becoming a little less popular at the high school level today with the very versatile 3-3 stack and 4-2-5 defenses gaining popularity. But the 3-4 defense can obviously be very effective when ran with the right personnel.

So I am going to explain what type of personnel you need, how to line up, and the responsibilities of each position in a base 3-4 defense. To keep it simple (and shorter), I am only going to go into the responsibilities of the front 7 in this post and you can check out my posts about running the Cover 2 and Cover 3 out of it. If you’re already familiar with the 3-4 then this probably won’t be very beneficial for you, but if your a new coach or just a fan that’s curious how the X’s and O’s work then you’re in the right place.

Here we go:

Personnel Needs:

  • Nose Guard (N)- Big, strong, physical, has to require a double team. In my opinion, the most important position in a 3-4. It is absolutely vital that he takes up at least 2 blockers on a regular basis.
  • Defensive Ends (DE)– Need to be strong, physical players, preferably with good size. They have to take on the offensive tackles every play.
  • Inside Linebackers (ILB)– Physical and aggressive, good tacklers, can not shy away from contact. Decent speed is a big plus.
  • Outside Linebackers (OLB)– Disciplined, intelligent, physical players. They have contain on the edge which takes a lot of discipline.
  • Strong Safety (SS)– This should be your biggest most physical secondary player. He will have more run support responsibilities than the rest of your secondary.
  • Free Safety (FS)– Smart, Great speed. He will have the deep middle zone in most coverages.
  • Cornerback (CB)– Speed and quickness. Whether you want to run a lot of man or zone your corners absolutely have to be able to run. You can’t coach speed.


So after you decide you have the players to run the 3-4, you have to get the alignment down. Alignment is the single most important aspect of defense. A huge percentage of big plays happen just because someone wasn’t lined up correctly on the defense. Here is what the base alignment should look like:

Note: This is a standard 3-4, there are other alignments you could call in a 3-4

Base 34 Defense

Alignment Rules:

  • Nose Guard (N)– 0 technique, head up with the center
  • Defensive Ends (DE)– 5 techniques, outside shoulder of the offensive tackles. (Can play 4 techniques, depends on your personal preference)
  • Inside Linebackers (ILB)– Head up with the guards 4.5 yards off the ball
  • Outside Linebackers (OLB)– 1 yard outside of the last man on the line of scrimmage (LOS), unless there is a slot receiver, then they need to be head up or shade outside on the slot. They can’t give up outside leverage.
  • Strong Safety (SS)– strong safety will line up on the strong side of the formation, 10 yards off of the last man on the LOS.
  • Free Safety (FS)– Free safety will line up on the weak side of the formation, 10-12 yards off of the last man on the LOS.
  • Cornerback (CB)– the CB’s alignment depends completely on the coverage called, in a cover 3 they would line up farther off, cover 2 or man they would line up closer.

I showed it against an I formation offense with a tight end, but the rules for where to line up don’t change no matter how the offense is lined up. Here it’s shown against a spread with twins on both sides and trips(3 WR’s on one side) if you want to see it.

Okay, so you’ve got the players, and you know where they line up at. Now what? This is where the real strategy of a defense comes into effect. What are every positions responsibilities? Before I start, remember that this is for a base defense. If you want to run some type of exotic blitz than multiple responsibilities will change.


Nose Guard (N)- I have kind of already covered this, but the nose guard has to eat up blockers. His main goal should be to run straight through the center and push him back into the quarterback. If he can successfully beat the center than they will have to double team him with a guard. Every time a guard helps on him is a time that the guard doesn’t block one of the inside linebackers. To summarize, the nose guard has to destroy the center every play.

Defensive Ends (DE)- The defensive ends main responsibility is also to take up blockers. They have to engage the offensive tackles every single play. So lining up on the outside shoulder their first step should be right at the offensive tackle, they have to fire off low to get underneath the tackle and punch with both hands. Ideally, they will get up under the tackles shoulder pads and stand him up. Once they’ve hit the tackle and stood him up, then they can read and react. Since they’re first job is to occupy the tackle and keep him from getting to a linebacker they can’t go up field. The defensive ends shouldn’t go more than a yard past the line of scrimmage. After they’ve done their job of standing up the tackle then they are free to move down the line of scrimmage to the ball.

Inside Linebackers (ILB)- The inside linebackers have to read the offense and do it without any wasted steps or giving up any ground. That means on the snap of the ball they need to be moving forward.

The best way is a quick read step, a short 6 inch step forward on the snap of the ball as they make their reads. Then once they make their reads they can take off downhill towards the ball, never running back or straight to the sideline, always towards the LOS. Their first read on every play will the be guard they are lined up across from. They will move from the guard to the full back, if it’s a single back under center formation then their second read will be the running back. If it’s a shotgun formation it will be whichever back is closest to them whether it’s the running back or quarterback.

It is very, very important that their first read every play is the guard, though. I can’t over emphasize that enough. The backs in the backfield can lie to you. The running back can take off like it’s a sweep left when it’s actually a quarterback run right up the middle.

The guards can’t lie though. They have to block for the play that’s actually being ran. If the guard blocks down on the nose then the ILB should immediately know that the ball is coming right at him and he has to step up and fill A gap (the gap between the center and guard). If the guard takes an 45 degree step to the outside towards the ILB then he immediately knows that the ball is going outside and he has to run through the guards outside shoulder. If he tries to run underneath the guard he will not make it to the hole in time. What is hard here is not over running the play.

It is important for the ILB to remember that it is the Outside linebackers job to make the runner go back inside so the ILB has to keep inside leverage. If he is running outside trying to cut off the ball carrier and the ball carrier cuts straight up field he’ll over run him every single time and create a huge cutback lane. The ILB absolutely has to keep inside leverage by making his aiming point the ball carriers inside shoulder. Then when the OLB makes him cut up field the ILB will be right there to make the tackle.

That is why it’s important for the ILB to look to his second read after he reads the guard. The guard lets him know which direction the ball is going, and then his second read will let him know exactly where it’s going so he can take the right pursuit angle.

As brief as I can make it; read the guard, then the back, always go towards the line of scrimmage. 

Outside Linebackers (OLB)- The OLB’s have one of the most important jobs on the defense. They are responsible for contain or controlling the edge. That means any time the offense tries to run the ball outside they have to force the ball carrier to go back inside into the teeth of the defense.

They can not allow the ball carrier to run to the side line and turn up field. To accomplish this, they have to maintain outside leverage, and the simplest way to do that is to keep their outside shoulder free. So they need to take on any blocker with their inside shoulder which will allow them to stay outside.

The first thing they should do is take a 6 inch read step forward while they make their first read which should always be whoever is on the end of the line of scrimmage (unless their lined up on a WR in which case they will read the WR). If the edge player tries to step out and hook block them back inside than they know that it’s coming outside to their side and they need to get out and make the ball carrier cut back up field. If the edge players blocks down away from them, they need to look for a pulling lineman or back coming their way to kick them out. If not they’ll feel the offense sliding the other direction.

When the ball is coming outside to their side it is important that they stay near the LOS, if they go up field then the ball carrier can cut inside of them and still keep going outside to the edge. They should not go any farther than a yard past the LOS. The OLB’s have to stay outside and force the ball carrier to cut back right into the ILB’s that are pursuing from the inside. If they see a pulling guard or back coming to kick them out then they need to aggressively attack the blockers outside shoulder and try to squeeze down the hole for the ball carrier. If the ball is going the other direction then they need to scrape down the LOS keeping their outside shoulder free watching for a reverse or bootleg back their direction before they try to pursue down field.


So that is the basics of how to run a 3-4 defense. Like I said in the beginning, I cover some basic coverage schemes in other posts (links are at the top) if you want to know how to run the secondary. I also want to emphasize that there is no perfect defense. No defense will stop every offense. What makes a defense great is when the personnel matches the scheme. If you have the right players to fit a 3-4 scheme then your defense will have limitless potential. If you do not, then you need to find a different scheme that fits your players better. In most situations, you can change your defensive scheme but a lot easier than you can change your players. Don’t try to force your players into running a certain defense just because it’s your favorite or you understand it the best. Branch out, learn more. Find what works for your team.