USC 4-3 Under Blitz Schemes
By Pete Carroll
Head Football Coach
In order to be successful on defense you need to develop a philosophy. You have to know what you want to do, how you want it to look, and how you want it to feel. A philosophy is like a railroad track. You have a clear cut direction in which you are going. If you start to get off track it becomes real obvious to you. If you don’t know what you want and what you are about you won’t know when you are off course. If you do realize you are off course you won’t know how to fix the problems you are having without a philosophy.
If you can’t write down your philosophy then you still have some work to do. If you don’t have a clear view of your philosophy you will be floundering all over the place. It you win, it will be pure luck. One year you will win, it will be pure luck. One year you will run a 3-4 defense and the next year you will run a 4-3 based defense. You will never get zeroed in on what is important.
I am an example of a person who got zeroed into a philosophy early. I went to :place w:st="on">Arkansas:place>
many years ago to work for Lou Holtz. Monte Kiffin was his defensive coordinator. He had just come over from :place w:st="on">Nebraska:place>
to take that job. He is now of course the defensive coordinator for the Tampa Bay Buccaneers and is one of the best coaches that has ever lived. Under Monte I was a part time coach in the secondary at :place w:st="on">Arkansas:place>
Monte ran what is known in coaching circles as the 4-3 under defense. That was his base defense that he had developed and perfected at :place w:st="on">Nebraska:place>
as a gap control defense to stop the run and pressure the passer. That was the first time I started to get hold of something that had a philosophy to it. I started to grow with this defense. After all the years I’ve been in football I’ve never coached anything but the 4-3 under defense. So I know this defense inside and out. I know the good side of the defense and I know the problems and weaknesses of this defense. I run it with one gap principles but can also make it work with some two gap principles.
What I can give you today is a real basic understanding of this defense. I am not trying to sell this to you as being the best defense. What I am saying is that for me this is the defense that I know best and can make work. The reason I run this as a base defense is that I know how to fix any problems that may be created.
I want to start out explaining the basic front end coverage. Then we’ll go over some of the more basic blitzes we run from this coverage. When I went to the NFL with the Minnesota Vikings, Monte Kiffin was there and we got together with another coach named Floyd Peters. He was from the :place w:st="on">Northern California
:place> area. He played for the Cleveland Browns and had coached all over the NFL. He was one of the great pass rush specialists that has ever been. He believed as well that the 4-3 under was the best overall front to use to rush the passer.
The 4-3 under defense has evolved over the years and adjusted over time. There are some different ways to do things from it. The presentation that I am going to give today is the “one-gap” approach. In principle we want to give our players a chance to know exactly what they have to defend. We also want to give them an attitude in which to do that. We want to be an attacking, aggressive football team. We don’t want to sit and read the play like you often have to with “two-gap” principles of play. We want to attack into the gap at the snap, get off the ball to play on their side of the field and get after the quarterback.
The big problem with any “one-gap” approach however is that it allows a ball carrier to get into the secondary if one guy makes a mistake. No matter how aggressive the defense is there is a great amount of discipline that goes with this defense. You have to be very strict about your positioning and the placement of your players. You have to have the ability to maintain relative spacing between your players.
When we talk about this front all gaps are lettered to give us a reference point. We letter the gaps on each side of the center as A, B, C, D, etc. We do this for the strong side and the weak side. For starters the Sam linebacker controls the D gap to his side of the field. He is in an inside-foot to outside-foot alignment on the tight end or what most coaches call a 9 technique spot. He can never get reach blocked by the tight end in this position. He is the force player for everything run to his side of the field and turns everything back inside to the pursuit.
The defensive end to the tight end side is responsible for controlling the C gap. He is an inside-foot to outside-foot alignment on the offensive tackle he is lining up against. If the tackle blocks inside then the defensive end has to close down with him in keep relative control of the C gap.
The nose tackle plays in the A gap to the tight end side of the field in our defense. We have done a number of things with this position based upon the opposition at times. We have put him right in the A gap, we have cocked him on the center at times, and as needed we have even played him in a direct shade technique right over the center at times. The way we play him on base defense is as an inside-foot to outside-foot alignment or a 1 technique on the center to the strong side of the alignment.
The prime spot on the defense to the weak side is the B gap player. He is an inside-foot to outside-foot alignment on the offensive guard to his side. He is a 3 technique player. He has B gap control but he can’t get reached or hooked by the defense due to the way we align him. The whole scheme of this defense is predicated upon not getting hooked.
The best pass rusher on the team is usually the defensive end to the open side of the field. That puts him on the quarterback’s blind side and makes him a C gap player in this defense. We often align him wider than this in order to give him a better angle of attack and allow him to play in space. We align him a yard outside of the offensive tackle most of the time. He has to play C gap run support but at the same time he is rushing the passer like it is third and ten. He has to be able to close down however if the tackle blocks down on him.
The front five players I mentioned are playing aggressive defense with their outside arms free. The only thing we can’t allow to happen is for them to get hooked or reached by the defender.
This alignment leaves open the strong side B Gap and the weak side A gap which are played by the Mike and Will linebackers. The Mike linebacker is in an inside-foot to out-side foot alignment on the offensive guard on his side of the field. The Will linebacker is aligned against the offensive guard to his side of the field. He is basically a protected player in this alignment and should make a lot of tackles. He has to control his weak-side A gap and play relative to the Mike linebacker and the Free Safety.
The Free Safety is the force player to the open side or weak side of the ball. He works off the defensive end’s play. The Defensive End works for leverage and force. The Free Safety works off of the Defensive End and fills where he is needed on run plays for example. If we are playing Cover 3 behind him the Strong Safety is going to have the middle of the secondary behind him but also fills off the linebacker’s side as needed depending upon the play. If the Sam linebacker does get hooked for example the Strong Safety will then have to come up and make the play. The offense will obviously gain a chunk of yardage on the play, but that is because there was a breakdown at the point of attack in our scheme.
The two Safeties are both fill where needed sort of players. The have to keep everything on their inside shoulder. All the players in this defense have to keep the blocks in their inside shoulder and force the ball carrier back inside to the next player. Here is an example of our base alignment against a pro set backfield with wide receivers split to either side.
4-3 UNDER DEFENSE VERSUS PRO SET
If you look at this front it is basically an eight man front against the run as we’ll bring the Free Safety down hard in run situations. This is a stop the run first type of defense. We want to outnumber the offense to either side of the ball. We call this particular alignment of the front an “under” and the coverage “flex” in our language. The open side of the alignment is the flex side and the tight end side is the strong or solid side. Those are our terms for the tight end side and the split end side of the formation.
The defense is a man to man coverage scheme for the corners in this example. If we call a cover one flex, we are man to man on the corners with the strong safety moving into the middle of the field. The Free Safety or flex side safety is down on run support. The Sam Linebacker has the tight end in man to man in coverage. He has him anywhere he goes for this defensive call. He never switches if we are in this coverage and will go with him if the tight end does go in motion.