Football University: The Cover 3

Last week we talked about the Tampa 2, which is essentially a cover 2 that turns into a cover 3 with the middle linebacker dropping into coverage. This week we're going to talk about a true cover 3, but before I get into that I want to talk a bit about how to exploit the weaknesses of a Tampa 2. 

There are two different routes that can beat a Tampa 2 pretty easily. The first is what's called a "flag" route or a "7" route, and the second is a "999". Both of these are assuming a 3 WR, 1 TE, 1 RB personnel group, though they could work with a 2 WR, 2 TE grouping as well, depending on whom you designate as your W, X, Y and Z receivers. 

Here's a diagram of a basic route tree (an important note--even numbers mean the receiver is breaking in towards the middle of the field, odd numbers mean the player is breaking to the outside). 

As you can see the flag route is basically the receiver running downfield and then cutting out at a 45 degree angle, and the 9 route is straight down the field. (A "999" route would be all three WRs going down the field).

Here is out these two routes exploit the Tampa 2.

The key here is the yellow spaces--these are the empty areas where there are no defenders to cover. The "X" and "Z" receivers have the best options at getting open, especially if they do a fake inside first. The spot in the middle is also good for a dump off to the RB coming out from behind the line. 

In the "999" route the bread and butter is the TE (this is where Vernon Davis made a living last year).

Here the "X" and "Z" receivers go deep, pulling the two safeties with them. If the safeties are good they shouldn't have any problem keeping tabs on those guys. The TE holds his block for a bit and then runs a slant to the middle where he can catch it in the spot vacated by the middle linebacker, or go for the inside corner spot abandoned by the free safety. 

That's the Tampa 2 and how to beat it. Now let's move on to a basic Cover 3. 

 

Basic Alignment

As the name implies the Cover 3 consists of 3 defensive backs deep, with 8 men in the box. 

In the Cover 3 the two corners drop back to cover the deep ball with the FS joining them in the middle. They then split the field into three equal portions. This is a bit easier to work with as a defensive coordinator than the Tampa 2 because you don't have to find a linebacker that's got the speed to cover a WR like you do with a Tampa 2. The weakside linebacker takes the curl routes on his right and the strong safety takes them on the left (strong side is the side where the TE is lined up). 

The benefits of running a Cover 3 is that it's a balanced defense that works well against the run (assuming you have competent linemen) because you have 8 defenders in the box. It also works well against the deep pass because you have 3 players covering the deep ball instead of just two. 

Player Responsibilities

DE- Align as a "5" technique - Outside eye up the OT. Attack "C" to "B" gap on run.
DT- Align as a "1" technique - outside eye of the OC. Attack "A" gap on run.
DT- Align as a "3" technique - inside eye of the OG. Attack "B" gap on run.
DE- Align as a "7" technique - head up the TE. Attack "C" gap on run.

 

A quick word about defensive line terminology. When talking about defensive linemen as a "3" technique, or a "5" technique it refers to where they line up at against the offensive line, like so:

 

 

When we're talking about "A" or "B" gap responsibility we're talking about where the defensive lineman's contain responsibilities are.

 

WLB- Align head up the OT. Contain vs. run, drop to curl/flat vs. pass.
MLB- Align strong side "A" gap. Drop to weak hook/curl vs. pass. Fill "A" gap strong.
SLB- Align outside eye of OT. Drop to strong hook/curl vs. pass. Fill inside fullback lead block vs. run strong, scrape to "A" gap vs. run away.
C- Drop to deep outside 1/3 with outside leverage on No. 1, zone technique (back to sideline)
FS- Drop to deep middle 1/3 with enough depth to get over the top of any outside vertical by No. 1.
SS- Drop into box at snap with 5x3 alignment on TE. Contain vs. run, drop to curl/flat vs. pass.
C- Drop to deep outside 1/3 with outside leverage on No. 1, zone technique (back to sideline)

The WLB and SS have to be able to force the run inside. If they don't there's going to be trouble since the only people to stop the runner are the deep guys.The also have to force WRs inside on curl routes for the same reason. If they get beat to the outside there's trouble again because of how deep the CBs and FS have to get. CBs have to keep the WR on the inside as well so they can get help from the LBs but especially from the FS. The FS absolutely must maintain his zone and not get out of position. He has to be able to move in and help a CB if needed and if he's out of position it could be disastrous. 

 

Weakness

Because of the deep coverage the Cover 3 can be susceptible to short passes, especially if you have quick receivers that can get outside in a hurry. 

 

3-4 Variations

Cover 2

I missed talking about a Cover 2 variation for the 3-4 last week, so here's a quick diagram of one way to run it out of a 3-4.

We actually use this one a fair amount. We bring both OLB in a blitz/rush with the CBs and LBs playing zone across the middle and the two safeties responsible for the deep half of the field. 

 

Cover 3

 

CBs still drop back as does the FS. This variation blitzes the weakside ILB, rushes the strongside OLB, and leaves the strong side ILB to cover the middle of the field. The weakside OLB covers the curl routes on his right. The curl routes for the strong side are covered by the strong safety. 

 

 

Here's a different way of running it from the other side of the field. In this case the strong safety drops back into coverage, with the FS coming up to cover the curl routes on the weakside. The weakside OLB rushes the passer, with the strong side ILB blitzing, The weakside ILB covers the middle of the field and the strong side OLB covers the flats on his side. 

A 3-4 defense can actually be more creative in how it runs zone coverage because it can send guys from multiple areas of the field without sacrificing coverage. Manusky likes to keep all his player standing and shifting so a QB can't figure out what the defense will be until the ball is snapped. By having OLB rushing you can rush one, or the other, or both, or none, which provides an immense amount of flexibility. This flexibility is a strong reason why more and more teams are switching to the 3-4.