Cover 4 is another Zone concept. Each DB takes 1/4 of the field from about seven yards out to the EZ. However, like all coverages, there are a lot of wrinkles. Some coaches refer to it as “1/4 coverage”, which should read “quarter coverage”
How a 3-4 defense plays Cover 4 over a 4-3 is all about the linebackers. Since a Cover 4 has the DBs playing back in a “prevent mode” (preventing any deep pass/long run), this leaves a lot of area from the Defensive End to the sideline to cover.
Since Von Miller has such an outstanding ability at rushing a passer they often move him down off the T/TE and let him loose in generating a pass rush and then dividing the other zones between the three other linebackers. This is shown in the graphic above.
There are scenarios where Von Miller and Shane Ray are responsible for short out type passes and runs to the outside. This doesn’t open the door for a lot of QB hits unless they know where the ball is going and can get to him before it’s released. However; since the QB knows he’s stuck with a short game, he’s dumping the ball quickly.
It’s dependent on the front Defensive 3 to get some sort of pressure, but with 5 OL guys to block them, it doesn’t always happen. It allows the OL to dedicate at least 2 men to stopping Derek Wolfe and allowing for another double team, as well.
There are at times where the under zones are divided up between three of the linebackers with the 4th being free to blitz, but we will address the concept of blitz vs. pass rush in a future post. The example of Miller/Ray in shot zone coverages is shown below.
Personally, I’m not a fan of putting either Von or Shane in coverage, not when we have such great corners, unless they need a rest from covering so much ground in man. Wade may have felt the same way since he rarely did it. Also, Cover 4 is made for four DL, not three, and the ones we had were not great at stopping the run. That puts more onus on the outside linebacker to stop the run and pass coverage.
Von usually looks horrible in coverage (man to man vs. Gronkowski), but can be great when dropping in that little curl/flat zone like he did vs the Patriots in the ’15 AFCCG. That resulted in a pick off Tom Brady to help set the tone early. It’s easy to cherry-pick a positive and negative play, but Miller and Ray are much better feeding on Quarterbacks than they are at man or zone coverage.
Which is why Denver uses Cover 4 only in certain down/distance circumstances. Mainly, the offense has to have a big yardage play or they’re already winning by a bunch, so they’ll give you the short passes to make you eat up clock. Or they show it, but then at the last second, one or both CBs move up.
One advantage besides giving your DBs less area to cover, is it does allow the defense to crowd the box on an obvious run play. The SS creeps up and you’ve now got eight guys in the QB’s face. So, it can take away the run, the deep pass, and some short passes between the seams.
The obvious vulnerability is screens, and slants. Good QBs can tear up this formation by finding the best short passes that will get good YAC (yards after catch). Also, the play action can be a demon. The defenders move up for a run and the QB zips one deep between the safeties. TD.