The Eagles have been mixing in a lot of Cover-3 the past few years. We already know what that is, so I thought we'd talk a bit about another one of Schwartz's base calls. Cover-4... or quarters for short.
My personal opinion, this is the best coverage in all of football, because it can morph into anything depending on how the routes are deployed. Routes are run this way, it turns into man. Routes are run another way it can turn into zone, and if the QB isn't careful he can completely misread it because the way the safety's move, it can look like a single high for example -- and the last thing you want is a quarterback throwing into what he thinks it cover-3 and it turns out to be 4.
When a lot of people hear Cover-4, or Quarters for some reason they get to thinking of it as more of a prevent style of defense. That couldn't be further from the truth. It's very much an aggressive defense and it allows you, unlike any other coverage to play with 9 defenders vs. the run because both safeties... not one like in Cover-3, but BOTH safeties have run fits.
To the picture. Both corners have deep a quarter of the field, and the safeties have each have a quarter, but this is where it gets neat because they are pattern reading.
CORNERS: The corners are actually playing man to man on anything vertical. If the receiver goes inside, he belongs to the underneath defenders.
SAFETIES: read the #2 receiver which is going to be a tight end or a slot receiver. If that slot receiver goes vertical -- and what's defined as vertical is gameplan specific, but lets call vertical anything past 7 yards. If that #2 receiver goes up the field past seven yards he belongs to the safety. If he breaks his route off anywhere underneath that, he belongs to the underneath defender and the safety will now look to help out the cornerback on his side and bracket the outside #1 receiver. Now we're gone from a Cover-4 to essentially a 2 man under defense with safety help over the top. If that #2 goes vertical then the safety will come down to take him and it can look like a single high defense.
vs. the run they are also reading the #2 receiver. Against 21 personnel for example, the tight ends will be their #2. If those tight ends stay in to block, the safeties scream up to fit the run. If they release they back into their coverage. This can make them susceptible to play-action.
UNDERNEATH: The two flat defenders, the outside linebacker and let's say the nickel corner will have quarter/flat responsibility. They say quarter/flat, but in most cases, any underneath routes are going to be played man to man by the quarter/flat guys. Remember, it's all working together as one, so anything under 7 yards belongs to them.
MIDDLE HOOK: that middle linebacker is only going to be worried about #3... and the #3 receiver could be the inside most defender in trips -- could be a tight end, in this picture, #3 is the running back in the backfield. That's the middle hook's man. He's going to be responsible for those little check downs. One of the ways I can always tell quarters is the middle linebacker is sort of flat-footed at the snap reading #3 in the backfield. If #3 stays in to block, he's going to look to get work and help out on those inside breaking routes. If #3 goes to the flat, then he's no longer #3. The flat defender will take him and the next receiver that breaks inside will be the new #3. This is the part that can be difficult to teach because it happens fast and these reads have to be made fast. I keep thinking back to how Smitty's Falcons struggled with this.
Those are just the basics. There are variations you can play off of this vs. certain formation like bunch and trips. There's a cut variation where the safety comes down and jumps crossing routes. There's Palms where the outside corner reads the #2 receiver instead of the #1 receiver in front of him, that functions as a trap coverage. Looks exactly like Cover-4 but can lead to a lot of picks, especially to the flat if the QB misreads it.
There was a time when Cover-4 was THE defense in the NFL because of how versatile it was and it won Super Bowls. Teams of course caught up to it like everything else, but defensive coordinators still lean on it. Guys like Zimmer, Fangio, Wade Phillips when he goes zone, Del Rio when he was coordinating, Todd Wash in Jacksonville when they're in long yardage will mix in quarters, Seahawks started playing a little more Cover-4 last year because that talent drain didn't allow them to just sit in Cover-3 all game... and Jim Schwartz.
