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An in-depth look into the Cover-2 scheme and how it works with the Steelers

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The Pittsburgh Steelers love their Cover-2 defensive scheme, but just how does it work? Let us explain.

NFL: Pittsburgh Steelers at Houston Texans Erik Williams-USA TODAY Sports

(NOTE: Many thanks to Drop the Hammer for his editing skills and for providing insight on a number of issues, especially on draft personnel. This is a cleaner, more insightful piece for his contributions.)

In an excellent feature that ran last week, Drop the Hammer examined the differences between a Buck ILB, a Mack ILB and the various “hybrid” positions utilized by the Steeler defense (Nickle and Dime backer, Box Safety). This article will expand on that feature by looking at how these positions function in one of our defensive staples: cover-2. We will study the scheme, its’ strengths and weaknesses, what is required of defenders to properly execute it and how the Steelers disguise and vary their cover-2 looks. We will also go inside the heads of our defenders and explain what they need to be thinking and looking for in cover-2 situations, as well as the pros and cons of playing this coverage given our current personnel.

WHAT IS COVER-2?

Cover-2 is a zone scheme that generally puts seven defenders in coverage. It is Mike Tomlin’s coverage-of-choice and the Steelers have played a good amount of it the past few seasons since Dick LeBeau was replaced as coordinator.

In cover-2, the corners and linebackers are responsible for five underneath zones while the safeties split responsibility for two deep zones. Underneath zones are generally those within 10-12 yards of the line of scrimmage, while deep zones comprise the area beyond 18 yards (the area between 12-18 yards is an intermediate area where receivers may run free but also risk being de-cleated by a closing safety). The five underneath zones are defined as follows:

  • Two “Flat” areas – the area on both sides of the field from the sideline to just inside the numbers.
  • Two “Hook-Curl” areas -- the area on both sides of the field from just inside the numbers to the hash marks.
  • One “Hole” -- the area between the hash marks.

Here is a diagram (note: pro hash marks are closer together than the ones shown here):

Cover-2 zone responsibilities

In a traditional cover-2 where four players rush the QB, the flat is defended by the corners. They are looking for short out-breaking routes from tight ends and running backs but will sink and help on deep routes up the sideline if no routes attack the flat. The basic coaching point is, “carry anything up the sideline until a flat route shows, at which time you should peel off and attack the shallower pattern. This means that Cover-2 corners must be able to run with outside receivers but also have the quickness to change direction, close on a shallow route, and tackle opponents in the flat (often slot WR’s, TE’s and RB’s).

The hook-curl areas are generally assigned to the Mack ILB and one of the OLB’s (Bostic and Watt, for example). The “Hole,” which is often used to throw check down routes to RBs and TEs, is defended by the Buck (Vince Williams). Crossing routes that pass through these zones are traded from one defender to another. It is important a defender does not lock on a crosser and run with him because that will void his zone. Cover-2 backers, then, must have lateral agility, communication skills and zone discipline (knowing what to do, why, and how your action matters in connection with the larger defensive scheme).

The two deep zones are split among the safeties. They may receive help on sideline routes from the corners, but cover-2 safeties have to get enough depth to see the development of all routes on their half of the field and must be able to react and run fast enough to cover them. Cover-2 safeties need vision, straight line speed, the ability to tackle, an outfielder’s ability to judge and defend a deep ball, and great study habits so they can predict particular routes based on what the opposing offense tends to do most often. The better ones also learn to “read” a QB so they can react a little faster, but that is risky because NFL QB’s are taught how to sell the Safeties a lie.

The need for specific Cover-2 skills often forces a coach to employ some kind of situational defense that will cover for his players’ weaker spots. Consider a 3rd-and-6 passing situation where the opponent is likely to favor some 5 yard pattern that would get the first down by simply falling forward. In that example the Steelers might replace the Buck ILB (Williams) with a fast coverage ILB (not on the team) or a Nickel Safety; i.e., a player with a Safety’s quickness but still physical enough to tackle like a linebacker. Morgan Burnett may be listed as a Safety but he has the tackling chops to do that job if the team has an extra Safety to play behind him. Do Wilcox or Dangerfield have the pure speed needed for a Cover-2 Safety? Corners Cam Sutton and Brian Allen have been mentioned as candidates as well. They have the speed, but can they think, judge balls, and tackle like a Safety?

For an even purer passing situation like 3rd-and-10, they might take out both the Buck ILB and a defensive lineman to create a 2-3-6 Dime package of two rush-capable DL’s and two Edge Rushing OLBs, with an extra DB (Mike Hilton?) joining Burnett at the second level. Now, rather than having two DBs and three LBs working those short and intermediate routes, there are four DBs and one LB. When playing cover-2, speed matters.

WHAT ARE THE STRENGTHS OF COVER-2?

The biggest strength cover-2 provides is protection against the deep pass. With two safeties taking away the middle of the field, and two corners providing help up the sidelines, QBs have to hit very small windows for any deep throw. Cover-2 also allows cornerbacks, whose eyes are already inside looking for flat routes, to become aggressive against the run. These “squatting” corners also make it tough to throw bubble and quick screens due to their tight alignment. Finally, with three defenders covering the middle of the field in the underneath zones, crossing routes can be hazardous to smaller receivers. It takes a man’s man to catch a shallow cross knowing a collision with Vince Williams or TJ Watt might await. That’s why receivers with the size and strength of Juju are valuable here. Juju is a better bet to survive crossing the middle than a guy like Eli Rogers.

WHAT ARE THE WEAKNESSES OF COVER-2?

The primary weaknesses of cover-2 are along the sidelines and the gap in the middle between the safeties. These can be exposed by certain route combinations. Here are a couple:

Fade-Flat

A fade-flat combo seeks to exploit either a slow read by the corner or the amount of ground a safety has to cover. Recall that the corner is supposed to carry the outside WR deep on the fade route until he sees someone coming to the flat, at which point he drops the deep pattern and charges back on the short one. That leaves a small window along the sideline where the QB can hit the fade before the safety can arrive in support. If the corner fails to read the short throw quickly enough – i.e., stays too long on the fade – the QB can simply drop the ball in the flat. It takes a quick read and a strong arm to hit the deeper pattern in that window, and even then the receiver is likely to get whacked. But when it’s executed properly the fade-flat combo is tough for a cover-2 team to consistently defend.

Fade-Flat vs. Cover-2

Divide

Divide is a route that should cause some trauma among Steelers fans since we’ve seen the Patriots run it effectively for years. Divide seeks to split the safeties with two corner concepts while sending a third receiver up the middle of the field. The QB looks off one of the safeties then throws the seam route over top of the linebackers. A target like Rob Gronkowski is perfect to run the divide since he’s fast enough to get behind the backers and big enough for the QB to throw the ball high. Tampa-2, where the Buck sinks deep into the middle of the field, is an ideal solution to Divide (and FWIW was pioneered by the 1970’s Steelers to take advantage of Jack Lambert’s speed). But against straight Cover-2, the only answers are to jam the receiver running the divide (not easy if this is Gronk) or to get a good pass rush that forces the QB to throw early.

NOTE: The ILB over the TE is the Buck; the ILB to the slot side of the formation is the Mack.

HOW DO WE DISGUISE COVER-2 TO CONFUSE THE OFFENSE?

Since every defense has its weaknesses, why don’t offensive coordinators simply run a steady diet of Fade-Flat and Divide whenever the Steelers line up in Cover-2? They would if they knew it was coming. There are go-to “beaters” for every defense. That’s why the Steelers, like most teams, mask their defensive looks by disguising the coverage.

Take the following look, for example:

The rotation of the $, corner and FS turn cover-3 into cover-2

Here, the defense appears to be lined up in a run-heavy cover-3 look. The strong safety (likely Morgan Burnett) is rolled down into a “box safety” position, where he essentially becomes a fifth linebacker. This leaves a single-high free safety, who is vulnerable to a double seam route like the one in the diagram above. If this stayed as cover-3, the free safety would have to cover both deep seams, and even a competent high school quarterback knows how to use his eyes to move that safety in one direction before throwing back to the other. However, with a bit of pre-snap movement and a well-timed post-snap rotation, cover-3 converts to cover-2, which takes away the double seam. In the diagram above, you see that rotation highlighted in orange. The strong corner rotates to a deep half to take away one seam while the free safety rotates and takes away the other. Put another way, the free safety shifts sideways to his Cover-2 position, the corner drops back to be the other Cover-2 Safety, and the box safety moves over to play as a Cover-2 corner.

This disguise can trick a quarterback into throwing into coverage by making him think he has one look when in reality he has another. This is just one of the ways defenses disguise cover-2 to win the X and O chess match against the offense.

CASE STUDY: COVER-2 STRONG SAFETY

All of this is fine in theory, but at the end of the day football is about execution. What goes on inside the mind of a player as he attempts to execute his cover-2 assignments? Let’s do a case study on the strong safety to find out.

I was a strong safety in college. That was [mumble mumble] years ago and football has evolved a great deal since then. I played a lot of “box safety,” which meant I rolled up like a linebacker in the alley to provide run support against the I-heavy offenses of the day. It involved a lot of taking on fullbacks and pulling guards and getting my nose bloody, with coverage in the shallow zones. Thank heaven I didn’t see much of today’s spread offenses because, frankly, I didn’t have the wheels to play in space. I survived in cover-2 because I was well-coached and I knew what to anticipate. Think of me as a poor man’s John Lynch. A very poor man’s….

The first thing a strong safety ($) has to consider is the situation. For this exercise, let’s say it’s 3rd and 7. We’re in a straight cover-2 call and the offense lines up in a 2x2 set out of 11 personnel (1 TE and 1 RB). Something like this:

The $ is aligned at 12 yards and is going to read the release of the tight end. However, pre-snap, he’s shouting at the Buck, “Stick! Stick!” This is because he’s watched a ton of film and he knows that in these situations this particular offense likes to throw a Stick Route – i.e., a short in or out-breaking route to the tight end. He wants the Buck to jump the TE right away and get on his hip. If it’s not Stick, and the TE is running something deeper down the field, this will help him as well because the Buck is jamming the TE to slow his release.

The $ is also identifying the formation pre-snap to check for motion. From a 2x2 set, he needs to know the adjustment if the offense motions the Y or Z receiver to his side, or the RB over to join the X and Y (triple receivers a/k/a Trips). The game plan will include “automatic” adjustments if he sees something like that. It might be a check to a different coverage, like Stress or Cover-6; it might be a coverage that leaves the corner on the Z receiver in single coverage; or it could be any number of other responses. The specifics don’t matter. He has to watch for offensive motion and yell something like “Auto to Trips!” to remind everyone of what to do when it happens.

By the time the $ has communicated with the Buck and the corner, the offense may be ready to snap the ball. Quickly, though, he wants to think tendencies. What routes will they threaten him with on 3rd and 7 from this formation? He’s not too concerned with the tight end running deep here because he knows the Buck will ride him and, unless this really is Gronk or Antonio Gates circa 2012, he’s probably not beating the $ up the seam or to the corner. They may try to clear him out with the tight end, however, and slip the Z receiver underneath on a short “Dig” or intermediate “in” route. And sure enough, when the $ checks the Z receiver’s alignment, he sees him out wide, near the numbers, where an “in” cut makes sense. The Z can’t run any sort of out-breaking cut from there because there simply isn’t enough field to make that work.

So the $ has his pre-snap read. The Buck will help with the TE if that’s the offensive target but in all likelihood it’s the Z receiver who poses the biggest threat to his coverage area.

Based on that read, the $ decides to cheat. How does he do that? Once the ball is snapped, he pushes off his inside foot and backpeddles hard. He’s trying to get as much depth as possible so he can see both the development of the routes and the drop of the quarterback. He wants to stay in his backpeddle as long as possible because this is the only way he can see all three (QB, TE and Z receiver). Once he turns his shoulders and runs to cover either the TE or the Z, he can’t see the QB. The QB, then, is his cheat-sheet.

If the QB takes a three-step drop, that means the ball is coming out quickly and the $ hopes his underneath coverage does their job. He will charge forward to lend his help on the tackle.

If it’s a seven-step drop the $ is turning and running because that means a deep ball is coming. He’s reading the release of the tight end but if it’s a seven-step drop he probably needs to find that Z receiver and get on his horse or his Corner will be on an island. Hopefully, he’s gotten enough depth in his backpeddle to have a good angle on the Z. If not, he will turn his back and run like hell.

But what he’s really looking for – because it is 3rd and 7, he’s done his film study and his position coach has drilled this into his head – is a five-step drop. He’s expecting that QB to hitch up on his fifth step, and when he does he’s getting his eyes right on that Z receiver. If the Z has made that “in” cut the $ is anticipating, he’s planting his back foot in the ground and driving hard on him with the intention of intercepting the ball or prying it loose from [that little so-and-so] with every inch of his being.

Sound complicated? This is classic football. Everyone relies on each other to do their jobs, and that communication Mike Tomlin harps about all year makes it possible to work together. And “Football IQ” – knowing the defense, knowing the shifts, seeing the offensive plan, and reacting the right way – is indispensible for the defensive field generals who make the calls. But wait, there’s more! The ball is snapped. The $ pushes off and peddles. The tight end releases up the seam and gets jammed by the Buck . The QB drops. And drops. And drops some more. That’s way too many steps. Screen! Screen! Now what? Screens are like Chinese fire drills. There are linemen out in space, wide receivers blocking downfield, defenders recovering from their drops and sprinting to the football. It’s freaking chaos. What does the $ do here? What are his rules? Guess what? There are no rules! It’s backyard football – go make a damn play. Avoid the big guys lumbering around in space, find a way to drop the ballcarrier before he gains seven yards. Run to the ball! Run to the ball!

4th down. The punter is coming out. Hold your fist in the air. What the hell is better than that?

The mental aspect of the pro game isn’t all that different from the one I played. The difference of course, are the bodies playing it. The speed. The size. The physicality. I wouldn’t have survived a series at the NFL level no matter if I did the right thing every time. Too big. Too strong. Too fast. For the guys who do make it to that level, however, the mental aspect is just as important as the physical. A player cannot survive without both.

THE STEELERS AND COVER-2: PROS AND CONS

As currently constructed, this Steelers defense is in decent shape to play cover-2. The primary underneath defenders – Williams, Bostic and Watt/Dupree – are serviceable enough. Williams is the weak link but the Steelers employ so many sub packages that he isn’t likely to be on the field in obvious passing situations. Any ILB the Steelers select in the draft is likely to offer an almost immediate upgrade in coverage over Williams and perhaps over Bostic as well. And if the rookie(s) are slow out of the gate when pressed into service, LJ Fort has shown some decent coverage skills. Looking ahead, any Steeler Nickel and Dime packages using an underneath group with some combination of Bostic, Fort, Draft Pick X, Hilton and Burnett seems pretty solid. Draft Pick Y to upgrade on Fort or Draft Pick Z to bolster the Safety depth would only help.

The corners are built for cover-2. Artie Burns is big and physical. He is actually good at jamming receivers off the ball, running with vertical routes and tackling receivers in the flat. His biggest problem seems to be communication, which may be a product of not having a reliable safety to work with (more on that momentarily). Upgrades at the safety position and another year under his belt should help him improve in 2018. I say “should” rather than “will” because he still has to do it. Young players should mature and most do, but that does not make it automatic.

As for the other corners, Joe Haden isn’t exactly a cover-2 prototype but he is a savvy veteran who uses his instincts to compensate for his smaller stature. He understands how to play the position; which is to say he recognizes alignments, routes and situations well. He also had some issues with communication in 2017, but that was expected as he adjusted to his new teammates. He should also be better in 2018. Mike Hilton has shown toughness and playmaking ability and excelled in just about every role he was asked to fill last season. Cam Sutton is long and rangy, if slighter of build than Burns, and seems well-suited to play cover-2 if he can also keep maturing. And then there’s the mystery man Brian Allen, who could be anything at all because we really have no data beyond hints, flashes, rumors and some truly remarkable measurements that haven’t shown up on the field. The corners look like they’ll be at least solid and could be more, unless several of those “ifs” go wrong together.

The bigger concern is at safety. For me, our ability to play effective cover-2 next season falls heavily upon the shoulders of one player: Sean Davis. Davis, who was often the strong or box safety last season, is expected to take on more of the free safety role as Morgan Burnett assumes Davis’ old duties. Burnett is not a speed demon, especially at this point in his career. The 4.44 draft prospect from 2010 is probably more like a 4.64 today. But like Joe Haden, his veteran savvy (ability to predict) and discipline should compensate for his lack of raw speed when playing the deep half. Burnett also wore the on-field headset while at Green Bay, which suggests he will be a huge asset in communication with both the safeties and the corners. This should help Burns and Haden, in particular, who sometimes failed to be on the same page as Davis and Mike Mitchell last season.

Davis has the physical tools to be a very effective half-field defender, but only if the team can rely on him to do it consistently. Will he make the right calls, checks and reads? Will he be disciplined enough to keep his aggressive tendencies from getting the better of him? Will QBs be able to bait him out of position with their eyes or pump fake him into mistakes? There’s an awful lot of ground to police as a cover-2 safety and little room for miscalculation. Is Davis there yet, mentally? We shall see.

The depth behind Burnett and Davis is another concern, which is why many of us expect a high draft pick at this position too. JJ Wilcox had his own issues last year, and Dangerfield (like Robert Golden) has proven to be more of a special teams ace than a genuine help at his named position.

ROUND 1-3 SAFETIES THE STEELERS HAVE MET

This isn’t a great class for safeties but there is a nice vein of talent right in the fringe-1st to late-3rd range that the Steelers will probably mine. The following names, grades and descriptions are drawn from BTSC’s Steeler Big Board. We are including only the players with Day 1 or Day 2 grades that the Steelers have met with. There are not many others who’d fit what the team is looking for. Personally, if I’m picking a pure cover-2 safety, I’m taking Justin Reid or Jessie Bates III. We lack a safety with either of their range and cover skills. If we could land either one, we would solidify the FS position for years, allowing Sean Davis to move back to $ when Morgan Burnett is done. That would make us a cover-2 team worth getting excited about.

1:25 SS/FS Justin Reid, Stanford [COMBINE & VISIT]. 6’1”, 204 lbs. Stanford smart, 4.40 fast, and ready to rumble. A favorite of the BTSC draft community, he fits the recent Steeler profile of looking for smart, fast athletes who can play both Free and Strong Safety.

2:01 SS/FS Ronnie Harrison, Alabama [COMBINE & VISIT]. 6’3”, 214 lbs. Another all-world physical talent but the unfortunate beneficiary of this year’s “Sold Too Hard And Too Early Award.” The doubts arise from rumors that he’s more a team player than an alpha dog, and the fact that playing across from Minkah Fitzpatrick and behind college football’s best front 7 could hide a lot of defects.

2:12 FS Jessie Bates III, Wake Forest [COMBINE & PRO DAY]. 6’2”, 195. A classic free safety who’d be an ideal fit next to Davis when Morgan Burnett is in the box, but would not be the replacement if Burnett got hurt.

2:24 SS/DIME ILB Terrell Edmunds, Virginia Tech [TOMLIN & COLBERT BOTH AT PRO DAY]. 6’2”, 220 lbs. An athletic wonder-child with the size of a small linebacker wedded to the speed of a true free safety. Terrell Edmunds would be right up there with his brother Tremaine in Round 1 if he hadn’t shown trouble absorbing the same level of football skills seen in the other Day 2 safeties. Open field tackling and poor angles (related issues) seem to be the primary issues.

3:01 SS/DIME ILB Kyzir White, W. Va. [VISIT]. 6’2”, 216 lbs. 100% football player and a fine leader on the field, but only an average athlete if your standard is “athletes capable of starting in the NFL.” He would be the box safety who’d either let Burnett stay deep, or would step in if Burnett went down. His lack of speed would be a problem if he was asked to play Cover-2.

3:12 SS Marcus Allen, Penn State [VISIT]. 6’2”, 202 lbs. A player always mentioned in the same breath as Kyzir White. He would also be the box safety who’d either let Burnett stay deep, or would step in if Burnett went down. His lack of speed would be a problem if he was asked to play Cover-2.

3:12 SS/FS Tarvarius Moore, SMU [VISIT]. 6’1”, 199 lbs. He was well down everyone’s list of Safeties until a pro day performance showed monstrous athletic talent that his film had managed to disguise. The scouting reports sound a lot like those for Sean Davis’ a few years ago.