FootballFulton Analysis

Fulton Analysis: Ohio State and Cover 4

Perhaps nothing epitomizes the transformation of the Ohio State defensive scheme following the Buckeyes’ Oregon loss than Cover 4 becoming a staple of the Ohio State defensive scheme.

Many observers are now familiar with how, under Ryan Day, the Buckeyes have traditionally pre-rotated their safeties before the snap—with one in the deep middle of the field and one over the tight end.

From there, Ohio State played one of two coverages that feature the safety in the deep middle of the field—cover 1 or cover 3.

But what is perhaps less well known is that Ohio State also “spot dropped” (also known as “vision and break”) within cover 3—meaning that the Buckeye defenders will drop to their pre-designated area (for example, the underneath hook-curl zone in cover 3) by matching their drops to that of the quarterback, and then shuffling in tandem with the quarterback’s eyes. As now-play caller Matt Barnes described in a coaching clinic about Ohio State’s zone defensive approach following the 2019 season:

If he’s looking this way, I’m going to shuffle that way. If he’s looking that way, I’m going to shuffle that way. I’m going to find a way to be in the window when the ball comes out, or when the front hand comes off the ball.

While spot dropping is the traditional way that defenses have played zone coverage, coaches that spot drop are now a distinct minority. Instead, “pattern matching”—or more specifically “man matching”—is the now prevalent method of playing zone defense throughout college football. The rise of pattern matching is perhaps most associated with Bill Belichick and Nick Saban time together with the Browns in the early 1990s.

With the Browns, Belichick and Saban primarily ran cover 3. And their defense repeatedly struggled with handling four vertical routes from the Steelers (in 1994 the Browns lost 5 games; 3 of them to the Steelers), as it put the defense at a numerical disadvantage with four receivers on the three deep defenders. As Saban stated at a 2010 coaching clinic:

I was the defensive coordinator in the early 90s and Pittsburgh would run ‘Seattle’ on us — four streaks. Then they would run two streaks and two out routes, what I call ‘pole’ route from 2×2. We got to where could not play 3-deep zone because we rerouted the seams and played zone, and what I call ‘Country Cover-3’ (drop to your spot, reroute the seams, break on the ball). Well, when [Dan] Marino is throwing it, that old break-on-the-ball [expletive] don’t work.

So, because we could not defend this, we could not play three-deep. When you can’t play zone, what do you do next? You play man (Cover-1), but if their [players] are better than your [players], you can’t play Cover-1. We got to where we couldn’t run Cover-1. So now we can’t play an eight-man front.

So Belicheck and Saban’s solution is what is now widely known as cover 3 pattern matching “Rip/Liz,” where Saban will designate the safety in cover 3 that will spin down and carry the fourth wide receiver vertical if needed (thus providing four deep defenders for four wide receivers), effectively allowing

As Saban alluded to in his comments, the limitation to spot drop zone is two fold. By definition, every zone has weak spots where certain pass patterns can numerically outnumber the zone defenders within that area. And if you cannot put adequate pressure on the quarterback, he will eventually be able to manipulate and find soft spots in the zone.

In man matching, by contrast, the coverage generally provides that defenders will remain in their zone area. But defenders implement it through a specific set of rules that tell them how to relate to the route combinations. Defenders will then play man on the receiver that is identified by their rules.

It generally works as follows. The defense will relate the coverage by keeping a plus-one to the receiver side (3 defenders over 2 receivers, 2 defenders over 1 receiver, etc). The defense then counts the receivers down from outside to in to that side (the outside receiver is the number 1 receiver, the next is number 2, etc).

At the snap, the defense then implements their rules based on how the receivers react. For example, in cover 4 “Mod” (man over deep) the corner will play man coverage on the number 1 (outside receiver) unless that outside receiver runs underneath (as on a crossing route) or a hitch. In those instances, the outside receiver will then be picked up by the next second level defender (generally the “apex” over the slot receiver—for Ohio State, that is the cover safety), with the corner then dropping to the deep quarter looking for a route coming from the inside, as Cameron Soran diagrams below

Man matching thus ends up with the defenders generally covering within their zone area—in the cover 4 Mod example, the deep quarter for the corner, the flat for the apex, the deep quarter for the safety—but the defenders are playing matchup man based on rules.

Although man matching may have come to prominence with Belicheck and Saban’s cover 3—and is now used within every zone coverage—it is most prominently featured with cover 4. Cover 4—meaning four deep defenders and three underneath receivers—may sound like a soft zone coverage.

But because it is only played with man matching principles, cover 4 provides excellent versatility, particularly in the role of the safeties.

Depending on the man matching principles used, cover 4 can range from an run-focused defense that allows safeties to trigger aggressively against the run (such as in quarters or cover 4 meg). Or it can function more like cover 2, with the safeties playing pass-first (such as in 2-read or cut). This versatility also allows the defense to play separate cover 4 variations to each side of the formation.

There is thus no better evidence in the transformation of the Ohio State defense following the Oregon loss than the fact that the Buckeye staff went from its previous aversion to pattern matching to prominently featuring cover 4 as a standard down defense. More specifically, Ohio State seems to largely be using cover 4 “Meg” (aka cover 4 man), as Soran diagrams below.

Cover 4 man puts the outside corners in man coverage on the number 1 receiver anywhere he goes (as Denzel Burke is playing to the top of the screen).

The next inside second level player—the “apex” defender (for Ohio State, the cover safety to the field, and the Will linebacker to the boundary)—and the safety to that side then work in tandem. The apex takes the number 2 receiver unless that receiver releases vertical—in which case he will cover whatever receiver comes into the flat—with the safety then taking number 2. Otherwise, the safety will play sky or “robber” coverage underneath the outside receiver’s route.

For example, below, to the boundary, the Apex (Will linebacker Teradja Mitchell) likely received a “push” call and quickly broke to take the number 3 receiver to the flat, while boundary safety Ronnie Hickman took the number 2 receiver releases vertically. To the field, the apex cover safety Marcus Williamson takes the number 2 receiver on an out breaking route to the flat.

At a personnel level, cover 4 fits well with the Ohio State safeties. It allows the boundary safety Hickman to trigger more aggressively against the run when he is in a sky/robber technique (as opposed to cover 2 where he needs to remain in cloud coverage to the deep half), allowing him to sit at 10 yards and come downhill.

Conversely, the field safety (Bryson Shaw or Lathan Ransom) is more protected than he is as the single high, middle of the field safety, generally capping routes to the field with limited run support responsibilities

It remains to be seen how far the Buckeyes will take their use of pattern-matching. Thus far, Ohio State continues to spot drop within cover 2 or cover 3.

Cover 4 man is fairly straightforward, with the corners automatically in man and the apex and safeties essentially reading a single receiver. Cover 4 man fits with Day’s overall philosophy of first stopping the run, as it allows the linebackers and safeties to fill more aggressively with less pattern reading.

From there, it becomes a question of whether Ohio State will use other cover 4 variations to keep offenses off balance; or simply mix cover 4 man with a more pass-first cover 2 for split safety variety. It also remains somewhat unclear how Ohio State will relate cover 4 to trips—which, to pattern match, requires the defense to relate 4 wide receivers to the 3 receiver side. There is some indication that the Buckeyes may likewise use cover 4 man, with the only difference being that the backside safety will then take the number 3 inside trips receiver vertically.

But even if Ohio State does not add to its current framework, the frequent mixing of cover 4 man and cover 2 is still well beyond the Buckeyes’ previously exclusive use of cover 1 and cover 3. Ohio State is now relatively sparingly using man coverage. And Barnes is principally using cover 3 in one of two situations. First, on passing downs, to play cover 3 buzz with Hickman dropping into the intermediate hook/curl zone to create a more layered approach.

Second, with simulated or creeper pressure, meaning that Ohio State rushes four and drops seven—but one of those four is a linebacker or defensive back (simulated pressure means that the defense walks up and shows a blitz but only brings four, creeper means that the defense does not show blitz but rushes a non-defensive linemen—for example in the clip below).

As such, even with a still relatively limited package, the Buckeyes have at least provided themselves the means to show multiple single high and split safety coverages, with the rush coming from different locations.