By Pete Carroll
Head Football Coach
University of Southern California

Thank you.  I am really excited to be here.  I want to start by thanking Nike for putting on these clinics.  It gives us a chance to exchange ideas, have some fun, and talk about the game we love. 

I was asked to speak about defense today.  I’ll try to give you some general thoughts that might help you on this topic.  I’m not trying to get you to change your defense, but I’ll show you what we are doing.

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 Arkansas many years ago to work for Lou Holtz.  Monte Kiffin was his defensive coordinator.  He had just come over from Nebraska 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 Arkansas.

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 Nebraska 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 Northern California 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.

The Mike Linebacker plays the first back out of the back field to the strong side.  The Free Safety plays the first back out of the back field to the weak side.  The Will linebacker plays the short middle.  The gives us a man in the hole in the short middle area of the field.  If we get a full flow by the backs to the strong side the Mike linebacker takes the first back and the Will linebacker takes the second back out of the backfield.  The Free Safety becomes the short middle player. 

If it is a full flow weak side play the Free Safety has the first back and the Will linebacker has the second man to the weak side.  The Mike linebacker becomes the short hole player.  In theory the middle hole player helps with the tight end but in reality he is the second line of defense against any breakdown in the pass rush.  They can help on the draw play, scramble by the quarterback, or screen passes that they can see developing. 

If the offense comes out in a different look such as a Twins look to one side, the basic core of the defense stays the same.  There are no adjustments to be made.  The defenders take their men in coverage regardless of where they line up.  The Mike linebacker has help in the middle from the short hole player.  However, he can’t allow himself to get beat in the flat.  The play action pass is a problem for this defense.  That is an area on which you really have to focus on reads and execution.  That is a critical aspect you have to practice.

Before we go any further, let’s talk about personnel.  You want to get your best players on the field.  The open side Defensive End has to be one of your best football players.  Size does not matter as much.  We want an athletic player who can move around.

At Nose Tackle you have to find a player who likes to mix it up.  We want a big guy in there who likes to get down and dirty.  He is going to get doubled a lot on the run and pass and is going to get down blocked a lot.  He has to be a tough player.  This guy can be a short and stubby type of player.

The other defensive tackle the 3 technique player should be your premier interior pass rusher.  He is going to get a lot of one on one blocks as it is hard to double team him because of where he lines up. 

The defensive end to the tight end side needs to be a defensive player that can play the run. He does not have to be a big time pass rusher.  He has to play the C gap and stop the run. 

The Mike linebacker is a traditional middle linebacker.  He is instinctive and makes a lot of calls for the defense.  He may be the guy with the most experience or the best feel for the game. 

The Will linebacker can be a smaller player.  He is generally protected in the defensive schemes and will not see as many blocks.  All you want him to do most plays is flow and chase the football.  We want our fastest linebacker at this position.

The Sam linebacker has to be a good containment player.  He has to be big and strong enough to play on the edge of the tight end.  He has to be able to run in pass coverage also. 

The defensive backs that are the best run defenders are our safeties.  The Free Safety is another player who makes a lot of tackles for us.  He has to have good instincts.  He is what we call a natural player.  You don’t have to coach this player too much.  He has to have a feel for the everything and understand the big picture.

The corners have to run fast if you plan on playing bump and run.  If they don’t run fast then you can still play with them.  But if your corners are not faster than the wide receivers you are facing don’t play bump and run.  Your asking them to do something they can not do and they’ll get beat deep.  It is a race when you play bump and run and if you can’t win the race don’t play bump and run.

If you have a million reads for your secondary you are crazy.  They don’t need that even at our level.  All they need to know is their primary responsibility and then secondary.  At the highest level in the NFL the pass game is as complex as you can imagine.  However if a defender can play the post and the seam route then they can learn to play at that level. The thing that kills and breaks down a defense is a ball being thrown over the defender’s head for a touchdown.

Teach your younger players to play the deep middle and forget about all the confusing rules.  The guy who is playing in the middle of the field has to figure out who can get into the middle.  We want our safety to play in the middle of the two receivers that can run the post route.  He wants to split the relationship with anyone who can get down the middle. 

When we play pass defense with our corners we play as tight was we can for the match up.  Against spread offenses we back them off more. 

If we get a one back or an Ace set the safeties are going to take care of it.  Everything else in the defense stays the same.  The Mike and Will linebackers take the back out of the backfield.  If he goes to the strong side the Mike linebacker takes him.  If he goes to the weak side the Will linebacker takes him.  The linebacker that is not involved in coverage drops into the short middle hole on pass coverage.  The Free Safety adjusts down to take the second tight end.

If the offense spreads out a bit into a double set to one side we don’t make any adjustment except to match up better with the safeties.  Everything else on the defense remains the same.  Everyone is playing their gap control and support schemes.  If the back goes in motion to leave an empty backfield set the linebacker to the side of the motion takes him.  The remaining linebacker bumps over to the middle to balance the defense and plays football.

If the offense comes out in a triples set the adjustment is made by the safeties.  In this case pictured the Strong Safety goes out to cover the third receiver to the strong side.  The Free Safety moves to the middle third of the field and plays the middle third.  Everyone else stays the same with the linebackers playing the remaining back the same way.  Trips to the other side would flop the role of the safeties.  Or if one is a better cover person that the other you can protect accordingly.

For a base defense to hold up you have to have some things that you can use to complement it.  When you play USC every single one of my players is going to have a blitz pattern.  The offense will have to account for every player on our side of the ball in their pass protection scheme.

The next thing that I am going to show you are some of the most basic combinations of pass rushes that we use with the under defensive front.  I want it to be multiple so that the defense doesn’t know who is coming and from where.

The first blitz that I am going to show you is what we simply refer to as “Sam and Mike”.  We are going to use the strong side linebacker and middle linebackers to rush the passer.  We slant our strong side defensive end, nose guard, and 3 technique to the open side of their formation away from their normal rush gaps.  The weak side defensive end is going to drop into pass coverage on this play.  The alignment is the same as before.  The Corners are line up in tight coverage but are going to bail out and play a three deep zone coverage with the Free Safety.  The Corners will play outside leverage on this blitz and force everything inside.  The Free Safety is playing a deep middle.  The weak side Defense End and Strong Safety are the outside defenders to each side.  They are playing seam coverage with the Will linebacker in the middle seam.  The Strong Safety and weak side Defensive End play what we call the hot receivers to their side.  Once the quarterback sees the blitz he’ll often throw to these short areas to his designated hot receiver.  If the tight end comes down the middle seam the Strong Safety collapses on him.  The Defensive End does the same thing with the back out of the backfield.

The Will linebacker is playing the hot receiver to the middle of the field.  That means he is finding the third receiver and covering him if he comes out on a hot route.  When we overload on the rush the ball with be thrown quickly.  We want good spacing in our coverage people so we can react by changing up, and make the play for a short gain. 

The formation doesn’t matter much.  We have to find the hot receivers on this blitz and identify them.  Another advantage the defense has in these types of stunts is the change up of the line.  The defensive line is now slanting away from where they have been playing the entire game.  That changes the landmark for the offensive lineman and gives the defensive lineman an advantage in his pass rush.  The defense has to have counter moves to the keep the offense off balance. 

This stunt can also be used in run defense.  To give us a change up we bring the Sam linebacker underneath the tight ends block.  We can also let the Sam linebacker play under all the blocks and bounce plays to the outside.  Those are changes we add to the base defense to keep the offense off balance.

Another way to get five man pressure on the quarterback is our Under Safety blitz.  On this stunt we are bringing the Free Safety from the outside.  The defensive line is slanting away from his blitz.  The corners are playing their same bail coverage and the Strong Safety is going to the deep middle.  The Sam and Will linebackers have the first two hot receivers and the Mike with have the hot third receiver.

A very effective stunt from this defense is called “Sam and Safety”.  On this stunt we are blitzing with both the Sam and the Free Safety.  The defense line slants to the Free Safety side.  The open side Defensive End comes off in coverage and everything else is the same.  The Mike linebacker and the drop end have the first two hot receivers and the Will linebacker has the third.

One of the problems we have when we drop the Defensive End in coverage is containment to his side.  When we drop the end it means the 3 Technique tackle has to work hard to contain outside.  That is not a good situation but we work hard to make it work. 

We also like to bring the defensive backs in the blitz scheme.  If they can disguise the stunt they can get there in a hurry.  We like to bring the Corner on a blitz as a change up from time to time.  The Corner aligns in a bump and run technique.  On the snap of the ball however he comes hard off the corner.  The Free Safety cheats back and covers the deep outside third.  The Strong Safety is covering the middle third and the strong side corner in this case is taking the outside third to his side.  The rush end and the 3 technique rush the A gap and the B gap.  The corner comes off the edge.

The Sam, Mike, and Will linebackers play the hot zones on this play.   You can mix up your blitzes according to your needs.  This simplistic blitz scheme lets you bring pressure from a number of different areas.  You can game plan the match ups the way you want with other combinations as well.  The important thing in this blitz pattern is that we are not changing anything in our basic schemes underneath. 

That is all the time I have.  I hope I have given you something you can take home with you today.  It is extremely important to have a philosophy that can guide you to the success you are looking for.  Thank you.  It has been a pleasure.