3-Deep Coverage: Basics

Bumped. GO BRUINS. -N

Defense is as simple as:

1. Coverage (how do you defend the pass)
2. Outside Run support (how do you defend the outside run game/screen game and force the ball back inside to the other 10 guys, who will be the outside "force" defender)
3. Interior Run fits (how do you fill each interior gap up front with a defender - if there is an open gap, then the offense has an easy path to the secondary)

Coverage determines the defense - a coverage sets the play of the front, tells your guys how you will defend the pass and also tells them how they will defend the run. Below are the three components of a defense.

1. Deep defenders cannot have run responsibility - they are coverage first. If your safeties are aligning at 15 yards to defend deep halves of the field in Cover 2 Zone, you cannot also ask them to come up hard against the run - it's just too much ground to cover.

2. The outside underneath defenders are the "force" defenders who cannot be beat outside and are the outside run support - who they are depend on the coverage. If you run Cover 2, you'll need corners who are strong enough to hold that edge and squeeze outside runs back inside, where the help is. However, if you run Cover 3, then your corners will have no run responsibility and it will be a safety and an OLB that will have to be the force defenders.

3. The other defenders are left to cover the remaining 6 gaps up front (Center-Guard, Guard-Tackle, and Tackle-TE) on each side and are interior run defenders. You will also need a cutback defender backside - in Cover 2 this will probably be the 7th man in the box, and in  Cover 3 this will probably be the backside force defender.

Your force defenders depend on the coverage. Corners may be force in Cover 2, but you cannot ask them to play force in Cover 3 since they are dropping deep. From there you can figure out the gaps you have to fill and which players will fit into each gap. And then you can figure out where and how to line 'em up and put your players in alignments where they will be able to do their job. Doesn't matter if you're in a 4-3, 3-4, 3-3, 4-4, 5-2, 6-2, whatever. You can call a guy a defensive end or a linebacker, and put him in a 2 or a 3 point stance, but what really matters is what you are doing with him after the snap. If you say you run a 4-3 defense, but base out of Cover 2, it will play differently than if you base out of Cover 3. If you line up in a 3-4 and run Cover 2, it will look pretty similar. It starts with the coverage and ends with the front/alignment, rather than the other way around.

So what does this have to do with UCLA?

Last season I saw two primary coverages - 3-Deep and Quarters. It's pretty tough to pick out coverages from watching from a TV broadcast but that's what it looked like to me. We ran others besides those two but those seemed to be the most common. It appeared that we started out the season with more Quarters and shifted to more of a 3-Deep team (there are some similarities, technique-wise). For a little bit about Quarters you can check this writeup from the EagleBank Bowl. This is what we were running when we gave up that long pass on the first drive of the EagleBank Bowl, as well as Jahvid Best's rushing and receiving TDs against us last season. Maybe those of you who check out spring ball will be able to tell what we will open up next year with after reading through some of this stuff. Since we ended the season with 3-Deep I'll go through it below and probably throughout the next week. 

3-Deep Coverage Basics

The overall defensive philosophy for 3-deep is that you need to protect the middle of the field. You cannot be successful if you do not. The goal of this defense is force the ball to go outside, whether it is in the passing or the running game. Against the pass, you want the QB to be throwing to the flats to the deep sideline area. The reason for this is that the ball is in the air much longer if he throws outside, which gives you time to get there. You want your underneath defenders to get into passing lanes to force a high throw with some air under it, which also buys you more time. The only "bullet" pass the QB should be able to throw is a pass to the flat, which you will concede but rally to make the tackle.

Run defense should also protect the interior gaps and spill the ball to the alley area (around the hash marks). You don't want to give up an easy run up the middle - again, if the back runs 5 yards, you want him to be running laterally rather than downfield. However, you don't want the ball to go all the way to the sideline - your force player should set an edge between the hash marks and the numbers. The LBs pursuing should make the tackle in the alley.

Against the Pass

3-deep means that you have three players responsible for deep zones. The hash marks are a good landmark, as the field is somewhat divided into thirds already. You will also hear it referred to as Cover 3 as well (Cover 1 being 1-deep, Cover 2 being 2-deep, etc), but every team has their own terminology and there are many different ways to run 3-deep coverage.

(Image not to scale)

From sideline to hash is 19 yards, hash to hash is 13.3 yards, and hash to sideline is another 19 yards. However in 3-deep you can ignore 5-7 yards along each sideline (the ball has to be in the air a long time to hit that throw and the DB can use the sideline for help), so each deep defender has roughly an area 13 yards wide to defend in their deep third. So your deep zones are going to look as they do below (again, not to scale - they should be equal width).

Generally you will pair 3-deep defenders with 4 underneath defenders. 

In very general terms (I'll probably hit technique in another post), the outside defenders are known as SCIF defenders - seam to curl to flat, which means they are looking for immediate threats to 1) the seams (vertical route down the hashmarks), then 2) the curl zone and 3) working to the flats. The interior underneath defenders work hook to curl and will usually key the backs, open up to their side, take away the hook, and expand to the curl. Their purpose is not just to cover guys who run into the area, but to get into passing lanes and force high throws. They need to feel crossing routes behind them and drop to take away the deepest threats or at the least force a high throw that buys time.

Note that none of these coverage zones are tied to position - doesn't matter who you have as long as they can execute the technique. You can drop 3 DBs deep, you can drop a CB in the flat and roll the coverage behind him, you can drop a safety down to play an underneath zone and rotate the other to the deep middle, you can even drop a defensive end as a SCIF defender, etc. Eventually I will probably get to variations, adjustments and blitzes out of the 3-deep. 

Against the Run

A deep zone defender cannot be relied on for run support. They can come in late and clean up, but you have to be able to consistently stop the run without them. Since you are committing 3 defenders deep, you have 8 left to stop the run. No matter the front you line up in, you'll have each defender responsible for a gap, and the SCIF defender playing "force", which means that they need to force the ball back inside on outside run plays and screens to give the guys inside time to chase the ball down. If that force player gets caught inside, the ball will probably spill down the sideline to the deep defenders downfield. Below is that happens when a force player gets caught inside. 

We looked to be in 3-deep this play, with Akeem Ayers as the force player at the top of the screen. He jumps inside to try to make the tackle and gives up the outside. The play went about 35 yards until Rahim Moore made the tackle past midfield.

To stop the run, the force player must a) hold his ground, and b) not be sucked inside. He doesn't have to make the tackle but he has the most important job. You often get problems with younger guys who just want to make tackles and get pinned inside rather than just taking on a block, squeezing the gap, and giving the other 10 guys time to get there and make the play. Playing defense is all about knowing where your help is and using leverage to allow them to help you.

This is a basic overview of what 3-deep defense looks like. I'll probably look at some of the important keys to being successful with this type of defense, as well as some of the specific techniques and CPs, adjustments, and variations.

Next: 3-Deep Coverage: Keys, 3-Deep Coverage: Technique, 3-Deep Coverage: Adjustments and Variations