3-Deep Coverage: Technique

Bumped. GO BRUINS. -N

Previous: 3-Deep Coverage: Basics and 3-Deep Coverage: Keys

If you read the last two installments on 3-deep coverage, you should have a pretty good idea of what this looks like. However, I didn't really touch on technique at all, which is the most important thing. You can't do anything unless you can teach it and make it work on the field.

To keep things simple I'll work with the basic cover 3 below. Against the run, to the 2WR side, you have "sky" force (strong safety) and to the TE side you have "buzz" force (linebacker). Since UCLA usually showed the 2-deep look and rotated a safety down at the snap we'll go with that. The interior 6 defenders (boxed in green) fill the gaps and force the ball to spill outside (defending the middle of the field first), and the free safety rotates to the deep middle. Rough pass drops are in blue, the basic 3-deep and 4-under.

Numbering

Eligible receivers are numbered from outside to inside. From left to right on the diagram above, the WR far outside is #1, the slot WR is #2, the back is #3, the TE is #2, and the right WR is #1. To differentiate, you can say #1 strong, #2 weak, etc.

Pattern Reading

Up until now, to keep things simple, I've just used terms like deep middle, deep 1/3, curl/flat, etc to describe coverage assignments. This is from the traditional way of playing zone defense, known as spot dropping. You are assigned a spot and you drop to it and cover anyone who runs into your zone. That's the type of zone defense most casual fans understand. To teach spot drops, you give a player a landmark on the field, such as the hashes or numbers, and ask him to use that to find his zone. 

It is easy to teach and simple to understand. However, the biggest weaknesses are that it is easy to "stretch" defenders in zones by overloading them while leaving others doing nothing. That is the whole concept behind most offensive concepts designed to attack zones, such as Norm Chow's stuff. You can have 1 defender trying to guard 2 receivers, while other defenders are "guarding grass".

To solve these disadvantages, most modern coverages today use pattern reading in some form or other. Pattern reading is sort of a combination of man and zone techniques. Defenders use zone concepts to figure out the biggest threat to their zone, and then kind of switch to man afterwards...I'm told that it's similar to a matchup zone in basketball (but I have no idea what that is). 

The advantage is that you can cover traditional "zone-beater" routes, because you are already anticipating these routes by the release of the receiver by understanding how offenses try to attack coverages. The major downside is teaching time and that you have the potential to give up a big play if someone makes an incorrect read. Below are some sample pattern reads for the weakside in cover 3 - different reactions based on what #2 weak (the back) does. 

It looks complicated (there are 5 pages of this in the playbook I took this from) but it is common sense once you get on the field and teach it. Basically, the player is reading the release of #2 - if he does not threaten their zone (by running inside or vertical), they will look to #1 as the biggest threat and look to cover him. 

Most defenses today incorporate aspects of both methods - you don't have to pick one or the other. But I think that it is pretty rare to see a defense does not use some pattern reading concepts even at the high school level today. Passing offenses have gotten so good at picking apart traditional zones, so defenses have evolved as well.

Deep Zone Players (FS/CBs)

In cover 3 the DBs are deep 1/3s players. Against the run, they are backup in case the ball breaks through. They play pass first - you don't want them biting on the run at all, or else playaction or trick plays will kill you. They have to stay disciplined and respect the pass until the ball crosses the line before helping out against the run.

The field is already somewhat divided into 1/3's - keep in mind you are playing soft on the outsides, so from numbers to hash (10 yards), hash to hash (13 yards), and hash to numbers (10 yards) are your general zones. 

The dotted lines are the "divider" line for the CBs which tells the CB whether to play inside or outside leverage. To the left, the WR is aligned outside of the divider, so the CB can take an inside alignment, anticipating an inside-breaking route. He is in perfect position to defend the post. This also prevents the offense from eliminating defenders from the picture by simply spreading them out to the sideline.

To the right, the WR is aligned inside the divider, so the CB can slide outside to anticipate an outside-breaking route. If the WR runs inside, he is no longer a threat to the CB and will be picked up by the FS or the LBs, and he will look to the TE instead. If the WR crack blocks inside on the Sam LB (the force player), then the CB becomes the new force player and is in perfect position to play outside contain (this is the only time a deep zone player will have a role in the run game).

The CB should be aligned between the WR and the divider line. That's the landmark - if he gets two vertical routes, he should be dropping right down that divider to play both with help from the FS and sideline.

The CBs are "1 to 2 players", which means they are reading from 1 to 2. Their first immediate threat is the #1 receiver deep. If #1 shows that he is not a threat deep by going anywhere but vertical, they will look to #2. If both #1 and #2 go elsewhere they will drop for depth and read the QB's eyes.

The CB on the left of the image:

1. He will align inside of the WR, butt to the sideline while facing the QB/OL and get a run/pass read while dropping back
2. He plays #1 as if he is going vertical - after #1 breaks off into the curl, his eyes go to #2, anticipating the smash combo, as the corner route is the biggest threat to deep third.
3. He will play outside and under #2 (FS will help on the inside and over top) until #2 breaks to the corner.

The Free Safety:

1. He will align on the hash at a depth of about 12 yards, giving the appearance of a 2-high coverage instead of a 1-high, which it really is.
2. At the snap, he will begin rotating towards the middle of the field, taking 3 read steps while keying #2 (slot WR) as the first vertical threat to his zone. He should be at about 15 yards at this point.He has to be aware of the TE as another vertical threat.
3. As the TE breaks to the flat immediately, #1 (WR to the right) becomes the new threat on that side.
4. Since both vertical threats break off to the corner, he will take cues from the QB and break on the ball as QB turns his shoulders and sets to throw. 

The CB to the right of the image:

1. He will play #1 with outside leverage and treat him as a vertical threat (if #1 does go vertical, he will play outside him and the FS will help inside).
2. As #1 breaks to the corner, CB will follow as if man coverage.

Underneath Coverage Players

The underneath guys play run-first and have additional run responsibilities. Against a run read, the force players will attack blocks with their inside shoulders, boxing almost everything inside and squeezing the gaps closed. 

Underneath defenders use similar principles as the deep zone droppers. The Sam LB and SS will usually be 2/1 players, reading from #2 to #1 working to defend the biggest threat to their zone. MLB and WLB will use a 3/2 technique, working from #3 to #2, again, working inside-out.

Same play as above, but for the 4 underneath guys.

For the Strong Safety:

1. He will align on the hash with the FS to present a 2-deep coverage to the QB.
2. At the snap he will step towards the LOS ready to play outside force against the run, making his run/pass read.
3. Once he reads pass, he should collision #2 (slot WR) and carry him out of the underneath zones. Since #2 is vertical and not a threat to him, #1 becomes his read, and he should be looking for curl, in, slant and get in the passing lane.
4. He should settle underneath the curl and take it away.

For the Weak LB

1. He is playing #3 to #2. He plays #3 as if he is going vertical (if he does, he will carry #3 to the free safety).
2.  Once he sees him break down just past the LOS as a checkdown, he looks to #2 and anticipates an in or a curl threatening his zone.
3. When #2 goes vertical, he can then play the QB's eyes and go back to #3 if the ball goes there.

For the Middle LB

1. MLB is also a 3/2 player. #3 doesn't go to his side, so he will look to #2.
2. #2 immediately breaks outside to the flat, so he'll just look to find work by reading the QB. He should anticipate a crossing route at 12-15 yards behind him.

For the Strong LB

1. SLB will align on the line as a 9 technique and play force against the run. If the TE blocks down on the DE, he will step down as well, maintain outside, and constrict the gap. If the TE tries to reach block him (gain outside leverage), he has to fight to keep his outside shoulder free and avoid being pushed outside.
2. As the TE releases outside, he will anticipate reach block and fight to prevent the TE from crossing his face.
3. After reading pass, eyes will be on #1, anticipating the slant or curl.
4. After #1 clears the underneath zones, he can rally to the TE in the flat.

If everyone does their job, a young QB might try to throw the smash combo left. Because the pre-snap read tells him that it's a 2-deep shell, he might try to go high-low on the corner and throw the curl, which is a pick by the SS. Otherwise, the ball will probably go to the TE in the flat or the checkdown - either way, the defense should rally up and make the tackle for a gain of 2 or 3.

Below are a few more of how 3-deep plays out against some more offensive plays.

One thing I didn't draw up are any trips formations (3 immediate threats to one side). While you can play the basic cover 3 against trips, it can put some stress on the defense. There are some adjustments you can make against trips and other looks while still using a lot of this same technique, and I'll get to that next time as well as some of the common ways to put on pressure with the 3-deep system.