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Defensive Back Techniques II - Terms and Communication

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We plan to continue to develop defensive topics during the offseason and go into pattern-reading, a technique by which the secondary can tighten up the zone coverage so that it appears to be man/man. However, before we go into this type of secondary coverage Clemson runs we need to continue to develop some terminology and basic techniques used in pass coverage so that you can understand the information presented.

We've covered the types of zone coverage that teams run before, but to reiterate this we'll give them again

  • Spot Drop Zone - Defenders have an assigned area to cover, and after the snap take their designated drop into that area and wait. They only react when receivers come into their zone.  The key point of the zone, in general, is that the DB is watching the QB and breaks on the ball at the right time to break the pass up.
  • Matchup Zone - A technique where the defensive back has an aiming spot to drop towards, but picks up the first receiver in his "zone" and plays him man/man as long as he's in that zone, analogous to basketball's matchup zone. Matchup zone is always used in tandem with pattern reading, which in the simplest terms teaches the defender the collection of routes used by the offense (patterns).The zones themselves are the same no matter what however.

Clemson plays a matchup zone under Steele, as do most of the better pass defenses in the nation. We played a spot drop zone under Vic Koenning in the past. Teams like Boston College and N.C. State, for example, also play this type of zone coverage.

We'll begin by giving some terminology for future posts, and as always if you have questions about clarification or something in particular you want to see covered, let us know in the comments.


First, the zones are depicted here for any basic C2/C3 coverage for reference. Other zone coverages use the same underneath zones, but the deep coverages change. The underneath zones (Hook, Curl etc.) extend to about 15 yards past the line of scrimmage. The deep zones extend all the way to the back of the end zone.
Generally, the deeper and wider the zone, the longer it takes the ball to get there once thrown. The defense takes advantage of this by not covering the shaded zones, and the boundary is used as an extra defender. Hook/Curl zones are manned by a single LB together in many coverages.



Drop Points and Aiming Points - Every zone has a starting point for depth and width of the defender's assigned drop. In any coverage, the initial alignment changes based on the formation the offense gives you. In spot-drop zone, the defenders have a point to get towards and they drop to that point, then react to the receivers. In matchup zone, they begin a drop at a 45 degree angle (underneath, the deep zones backpedal unless there is rotation) but drop to the receiver and a general area, not a point.

They should always maintain their leverage during the drop however, and you don't let them get into the seam.

Flow - When 4 receivers go to the Strong side. Its important to know because the assignments given dictate different things for a defender (linebacker or DB) when flow comes to him or away from him, and knowing whether to change your zone drop depends on whether there is flow, so you dont end up covering air.

Flood - 3 receivers go to the Weak side. Similar to above. Either can be by action or alignment. It generally points to a bootleg action.

Split/Dropback - 3 strong and 2 weak.

What we mean by action vs alignment is basically to say what the offense is doing after the snap vs. pre-snap. By alignment, Flow means that there are 4 possible receivers to the strong side of the formation. This means that the offense aligns 2 or 3 WRs to one side, with either a TE or RB also on that side of the quarterback, as below.


By action, for example, say you're in the ace-formation with a two receivers to each side as below (TE counts as a receiver). If the back breaks on pass routes to the weak side as well as the TE, its Flood-action as below.


As an aside, it should be pointed out that some defensive coaches would call the 2-WR side of the above formation the strong side because the slot WR should be a better pass-catcher than the TE, but you get the idea. 

Pattern - a collection of different routes with an intended purpose.

A pattern can be to hi/low a defense, by running a 5 yard slant and a 15 yard post on top of it. It could be to horizontally stretch them by running a RB into the flat on a flare route with the WR running a 15-yard In route. There are many patterns in an offense's playbook that are studied and broken down for each opponent, and pattern-reading is instruction of those pattern's to your defense. Below is what is called a Smash pattern, a combo of the corner/flag route and a hitch, specifically designed to attack Cover 2 Zone.


Some teams only patter-read in certain coverages, for example Cover 4 or Cover 8. Clemson and Alabama, as well as many teams that employ matchup zone, do it on every zone coverage.

Leading and Trailing - terms used when a defender in zone coverage intends to pick up the receiver closest to him in coverage, while the defender away from him picks up another receiver based off of the coverage of the first.

Basically this means that the zone assignment changes based on the routes being run by 2 receivers together. This applies most often to linebackers who may have to pick which RB to take if both take pass routes to one side, or when the TE and RB come into their area. The first defender picks up the first receiver who crosses his face and the trail defender plays the 2nd.

Leading-trailing1_medium Leadingtrailing2_medium

Push Technique - A call made by a defender (usually a LB) to push the adjacent underneath defender to the next receiver. Its used together with an "I'm Here" call of some kind, telling him that you have his back in case two receivers come into the area, and you will pick up the guy going deeper.

Pushing your adjacent underneath defender to the next threat alerts him to push through where he normally drops in his zone coverage and onto another receiver, usually the #2 receiver to that side. This way you account for situations where the offense floods one side with receivers.


Say the offense lines up with a Flanker and TE, and two RBs, with a Split end to the other side, as in a 2-back split set or I-formation. Then after the snap, both backs to strongside, putting 4 guys in the area (FL, TE, RB, FB). You don't want someone to stick totally to his assignment when they send 4 guys into your side of the field, so the backside LB (e.g., Will) will yell "push" to the Frontside (MIKE) to tell him to keep going laterally and pick up the next guy over. Then the backside LB will pick up one of those RBs or a TE coming across underneath in his coverage.

If two of those receivers come across the middle, the frontside LB picks up the FIRST one underneath, and the backside picks up the 2nd after making an "i'm Here" call to let him know.

The call itself can be anything, and depends on the coach. If not "push" it could be "green" doesnt matter, but its in there.

Working the Shoulder - A term used when the receiver runs a hook or curl, and turns his back to the defense. The defender assigned to him must "work" to one shoulder and attempt to get his hand between the receiver and the football.

This is why you see Corners come from behind or the side to knock balls away, they are taught to run to his shoulder (whichever side the route breaks towards, or the side from which you have leverage). If you mess up and take the wrong shoulder and he makes the catch, it could be a bad day for you. This is the best way to break up a pass though.

"Cutting" - The defender sees his key running to the outside and cuts underneath the inside route that will usually be run over the top. He is allowed to turn his back to the QB to run towards the WR.

For example the LB is keying (watching) the RB to his side of the formation, and his pass assignment is the middle hook/curl zone. There is one WR outside of him. Let the outside receiver run a curl or Inside route towards the middle of the field, and the RB runs a flare route to the sideline. The LB begins his normal drop and the RB crosses his face, then should expect the WR to be running inside, and sees him doing so. He can then turn his back and run to the WR and picks him up man/man. Someone else with Flat responsibility has to take that RB.


Pattern reading is based on the idea that when someone runs outside on a route, there is a very good chance that someone behind you is running inside, trying to vertically and horizontally stretch a defense.

Stacking - When the keyed receiver on a play, like the RB, blocks, the LB/SS assigned to read him is free to take his drop straight back and read the QB. He stays over the top of the back in case he releases, called stacking.

In making his read, he uses the slide technique to cover any receiver the QB is looking towards.


He will sometimes have the ability to attack two different routes. If the stacked defender takes his normal drop and ends up being underneath an inside-running WR, he takes away the In-route with his body. This is called having "position" on a threat. His eyes though are trained on the RB/TE coming out on a late release, so he reacts to him with his eyes, and works to his direction. In effect, he has attacked with his eyes and his body. That LB has time to think and react to the pattern being run.

Covering the Flats and Crossing Routes

Covering the flat is very important in pattern reading because most passes are thrown at short range. The player assigned to cover the flat can be any position, from Defensive end to Cornerback but the technique is the same for all. He takes a 12 yard drop at a 45 degree angle inside the outermost WR's position, and NEVER turns his back to the QB, and never cross a WR's face -- just stay as wide as the widest possible threat (a back or receiver).


For example, say youre playing Cover 3 and the Corner just does his backpedal deep (instead of locking on a WR man/man) and the LB is covering the flats. The WR to that side runs a square-in and there are no other possible threats. The LB has to take a drop and be watching the WR but never turn his back to run with the WR. He drops back at an angle to intersect the route and then gets within one-arm length of the WR, then runs the In-route with him man/man and only when in one-arm length can he turn his head to the QB.Flat3_medium

Now if the RB peeled out of the backfield from a block to the sideline, the LB then has to let the WR go and close on the RB as soon as he crosses his face. He can't let the RB get wider than he is playing up the field. The other defenders covering the middle would have to pick up that WR. Similarly, if the TE is running a crossing route that brings him to your assigned flat, you must pick him up and let the WR go.Flat2_medium

Buzzing the Flat - A technique that doesn't use pattern reading, but is germane to any zone defense. The flat defender takes his drop as above, but his job is to take away any out-routes. Together with a Cover 3 scheme with the deep Corner playing to the inside of the WR, this can help take away both inside and outside routes.


2nd Through the Zone - Every flat defender must pick up the 2nd man through his zone in man-to-man coverage.

Generally the first man through the flat zone (be it the TE or WR, usually WR) is intended to clear the area, which means he's supposed to suck that flat defender out of his assignment and make him late getting back down to the RB. What the flat defender is supposed to do is get depth and stay under the WR's route to make the QB throw over him, but also not be so deep that he cant get down to a RB that is releasing out of the backfield on a sideline route. When that RB releases he must pick him up in man/man, its no longer zone coverage.

Walling Off - The defender turns his body towards the receiver and makes him go around, disrupting the route. Meant to prevent a crossing receiver from getting an easy opening behind the defensive line.


This is a bit like setting a pick in basketball, and it disrupts the timing of the pattern, since most short crossers are timed routes. Usually its a LB assigned to the flats or a LB whose zone is over the middle and he turns towards the slot receiver and makes him slow down, stop, or bounce back the other direction. The LB steps FORWARD to the LOS, then turns to the receiver. One must be careful not to get a holding penalty and it needs to be hands-free and underneath the 5 yard contact zone. Once the attempt is made the LB picks him up man/man whichever way the WR goes.

Still, the advantage between a WR and LB goes to the WR. If I can make him turn and run around me, it gives me a half-step to react to him and another second for the line to get a sack. This is partly why slot guys tend to be smaller and quicker by design.

Intersecting - In attacking a short crossing route, the defender has already gotten too much depth to wall-off the receiver, so he must pick a spot and intersect the route ahead of the receiver.

Passing Off - like an "i'm here" call, and means that the adjacent defender has stacked and has no one to cover man/man in his zone.


Iin the above example, the TE runs up the seam and the SAM forces him to run wider, and towards his SS help. He sees the WR coming underneath across the formation and Mike has depth, so SAM picks him up and the MIKE drops to take the crossing TE.

Having the free defender nearby is not assured, and sometimes this is why coverages are blown. Also, the crossing slot WR may turn upfield into a hook route and end up uncovered at all.

In all of these final definitions, you must keep in mind not to be sucked down too far. Patterns are constructed for a reason. If there is a low crosser behind the DL, then there is going to be a deeper crosser. The low crosser may want you to jam/wall him, because that means you are not getting depth to cover the TE behind you on an In-route.