The Vikings defense is still a topic of contention among fans, with some maintaining that our coverage scheme is an issue, while others claiming that it is merely the skill level of our players that have held our defense back in recent years. While it's evident that there are issues that need to be fixed, one thing missing in the discussion is an actual discussion of the coverage concepts and why they are employed.
Part 2 of the 2 part (Part One here) series on the Vikings defense, exploring the Vikings version of the Tampa-2. Join me after the jump for a discussion of the base coverage concepts on pass plays.
The Tampa-2 is an evolution of Bud Carson's Cover-2 developed for the Pittsburgh Steelers in the 1970s. Originally designed to prevent outside runs, the Cover-2 concept was wildly successful at pass coverage, freeing up a talented defensive line to make plays in a single gap system.
It relied on strict discipline from its players, and in particular required the secondary to buy into the system. His system, much like ours, require physical cornerbacks who can make tackles in the run game and push receivers once they leave the line.
Carson first installed the Cover-2 at Georgia Tech, before being hired by the Steelers four short years later in 1972.
A "traditional" 4-3 one-gap system, the Cover-2 relies on the middle linebacker (Mike) to make a number of important calls in pre- and post-snap defensive configuration. In Carson's original Cover-2 position, the Mike would often man up against an inside receiver, usually the tight end or slot receiver. If he didn't, he would cover the underneath zone in the middle (usually on plays where the end stays in to block).
The Mike wasn't the only one responsible for that slot receiver or tight end, however. The strongside (Sam) backer would jam that route before entering his outside zone of coverage. If the fullback is aligned to the strongside (as above), the Sam might man up on him if the fullback leaves pass protection and also if the corner is assigned an underneath zone. In these instances, the corner's zone would expand to cover much of the Sam's original responsibility.
The weakside linebacker (the Will) would either track the halfback or immediately drop into his zone. If the halfback moves out on a wheel route, the Will's coverage is dictated by the corner's coverage—a corner in zone would allow the Will to cover the halfback, but man coverage by the CB would force the Will to cover the flats.
If the Will is on man coverage, he'll fire out to hit the halfback, then play inside the route, while pushing the back outside. Important here is staying between the halfback and the quarterback.
Similarly, the cornerbacks, generally big, physical players, would jam the receivers and force them inside.
As a general principle, the inside receivers were funneled out by the linebackers, while the outside receivers were funneled in by the cornerbacks.
This allowed the safeties, who have backed up, to define which receiver they needed to cover the top of. Safeties benefited from this reduced pressure, and were free to make plays or force turnovers.
The corners, depending on the call, would either settle into small zones underneath the safety or man up.
As a base defense, this was somewhat revolutionary—teams would generally plan "Man Free" coverage that had each player cover an offensive skill player man-to-man while the safeties roved downfield, or Cover-3, where a strong safety would drop into the box to cover the run, while the corners and free safety would each have a third of the field.
The important thing here is that the Sam and the corners absolutely need to do a good job jamming the receivers because the defense relies on two key concepts: timing and angles. The defense needed to disrupt the timing of the routes, particularly the check downs in the flats. This meant that the cornerbacks needed to beat the receivers at the release and hit them whenever possible. Beyond that, the linebacker lined up over the tight end needed to hit that end hard (you'll see this in the first few plays of the 1972 game that Eric posted, despite the fact that the defense wasn't fully installed at that point), and would often do so regardless of the Mike's read of a pass or run play.
Disrupting the timing would allow the four man line to reach the quarterback without relying on the blitz. Beyond that, the plays would take longer to develop tightening the windows for acceptable passes and making the angles much more difficult (like forcing downfield fades).
Because Coryell's Roving-Y and triple sets hadn't entered the league, there was almost always only one receiver or tight end inside the numbers, and they would define the "closed" or "strong" side.
Wade Phillips' version of the 3-4 Cover 2 had the safeties move inwards and have the corners choose to cover man if they detect the receivers running fade routes, go routes, or post routes.
The base defense does not make a distinction between the strong safeties and the free safeties, and the Vikings do not generally find that difference to be important in play calling or player identification.
The weakness here is severalfold: first, the Mike needs to be speedy, smart and recognize all the checks and alerts before the play starts and after the snap. Without that, the entire defense collapses, and seam routes are devastating. Similarly, the nose tackle must command a double team, or disrupting the timing doesn't matter. Finally, the scheme sets up serious problems along the sidelines in the passing game, especially against receivers who are good off the release.
In response to these weaknesses or liabilities (and changes in passing rules in 1978), Tony Dungy teamed up with Monte Kiffin in Minnesota to combine the Cover-2 concepts with Kiffin's pass rushing schemes to create the Tampa-2.
There aren't an extraordinary amount of differences, as you'll see below:
Here, the Mike and corner responsibilities are definitive and clear-cut. Instead of reading the Y's route (tight end or slot receiver) in every situation and also reading the play for run-pass, the Mike will just read the play for a run or the pass and drop deep on pass plays. Here, the Mike doesn't need as wide a range of abilities, but is still a critical part of the defense.
The Mike still will need to determine the type of route being run by the inside receiver, but has more time to react to what the tight end or slot will be doing. If that receiver runs a vertical route, the Mike will run with that receiver and drop inside of it. If the route is not vertical, he simply moves up 15 yards from the line of scrimmage and manages his zone (usually managing it inside-out, where he will pick up receivers entering from the inside of the play, then the outside). The Mike will also need to run to the ball for any underneath routes.
Both the Sam and Will linebackers will drop to hooks on pass plays, which are the zones above the ends, 10-12 yards from the line of scrimmage. Here, the Sam has more read/react responsibility than in Carson's Cover-2. In Carson's system, the Sam would almost always hit the Y receiver, and then read the play during and after the hit, a much easier job a second or so into the play than immediately at the snap. Both the Will and Sam backers will be liberal with their zone assignments, and will slide their zone based on what they see in the QB's eyes.
The corners will jam and reroute the receivers to move inside before dropping into their zones 10-12 yards from the line. It is up to them to rush to any pass in the flats, and they are expected to read those plays quickly enough to meet the ballcarrier within one or two yards of the catch (made easier by the fact that these passes can never truly be "led" or caught on the run, the way a slant or go route can).
The Mike's zone coverage 15 yards deep will push the safeties to the sidelines, allowing them to cover the fades and go routes on the sidelines. Both safeties will read/react based on the receivers they are over top of, and then drop 15-18 yards deep in their zones. In this way, the Tampa-2 resolves the seam/sideline issues of the original Cover-2 scheme.
The nose tackle and the Mike are still critical parts of the defense, but because the timing of the routes are not the focus of the base coverage, the defensive plays don't hinge on the nose tackles as much as in the original system. More than that, the nose tackle's responsibility to funnel plays to the Will (see the Front Seven article) is more important than occupying two pass blockers (although still a big responsibility). The Mike maintains his status as a key player (the "the straw that stirs the drink" according to Bryan Mullen), but burdened with fewer responsibilities and easier reads. Because he drops into a zone, the speed demands are not nearly as high, and if there's a vertical route from an inside receiver, there's also a good chance a safety will bracket that receiver up top because at least one outside receiver won't challenge a deep zone (by running inside or a curl).
Important in both positions, too, is the use of on-the-field landmarks. In the Tampa-2, the safeties should drop to the top of the numbers (hugging the numbers on the field, but staying inside of them, toward the hash marks). The outside linebackers will drop to the position in the center of the hash and numbers, and will generally slide within that zone based on how they read the quarterback.
The landmark and zone system did cause some player confusion when initially implemented—the system did not have a way to account for a number of players as they ran routes onto the field (think of the flats, for example. Underneath routes are a problem, too). The answer is that the system is not designed to account for every passing option; it's designed to limit big plays. Two quotations by the system designers will do a better job explaining it than I can:
"If you can make them punt, you've done your job. You don't have to be a hero with an interception"
— Bud Carson
"[G]uys ... would ask, 'If the tight end does this, who's got him?' And we'd say, 'Well, no one's got him. The defense is going to take care of it. The offense is going to complete some passes. If they're patient, and they just dump the ball off, we've got to come up and tackle well. But at some point, one of our defensive linemen will get a great rush, or we'll stop a run and make it third-and-nine. Now they aren't going to be able to throw that six-yard pass anymore."
— Tony Dungy
That's not to say, of course, that the system denies playmaking opportunities. Specifically, this system enables good safeties to make interceptions if they are particularly intuitive and enterprising. It simply does not encourage gambling from its cornerbacks, which can sometimes be an issue for players transitioning systems. It was no surprise, for example, that Nnamdi needed time in the switch from Oakland's Cover-1/Man-Free concepts to Philadelphia's zone/discipline system.
Also evident as a result of this philosophy is that you need corners who are sure tacklers. The Carson Cover-2 needed strong corners to manhandle the receivers and disrupt the run game from the outside, but the Tampa-2 system requires corners to be overall good tacklers, not just good hitters.
A good example of how this base defense gets set up is against the Lions in Week 3. It's fairly vanilla and like what I've described. The only difference is that Greenway does jam the tight end, sort of like in Carson's Cover-2 look above. He doesn't run up to do it, however. Take a look:
Here, we see the basic assignments
The corners are funneling the receivers inside, the Sam (Greenway) is prepared to funnel the tight end outside, and the Mike (EJ Henderson) is reading the tight end to see if he'll go vertical
The corners have done their job and are prepared to pass the receivers onto the next zone. Greenway (Sam) is slowing down the TE, and Henderson (Mike) is reading the route, but prepared to backpedal based on what he sees. Erin Henderson (Will) is reading the QB's eyes.
Offscreen, all the receivers are covered—the Z, X, and Y have all found deep routes and the defense has accounted for them. Stafford checks down to Jahvid Best behind the line. Best looks to have acres of space, but Greenway (Sam) and Griffin (RCB) are closing in on him.
Best only gains 3 yards on the play.
This fits the principle perfectly. On first down, they prevented any gains. On second and long, they only allowed 3 yards on the pass, and set up third and long, where small pass plays are not a threat. The corners did not sit under the receivers in order to pick the ball, but maintained discipline to prevent big plays. The linebackers maintained coverage over the middle, but flowed to the ball based on the play. The nose tackle (Ayodele) commanded a double team, while Williams stunted over to provide additional pressure.
The concepts in the Tampa-2 are simple, and the execution does not require extraordinary talent at every position—the defense stresses good nose tackles and good middle linebackers, and even then, these players do not have the demands that other systems might impose on them.
Remember, this is just the base defense, however. The nickel, Cover-1, and blitz packages will all look different, and will require different skills from different defenders. While they will generally all be tailored to one gap attacking from the 4-3 front (except the 3-3 nickel, although our version sort of does anyway), the back seven will have to display a wide variety of skills in order to execute the full defense.
This is distinct from some 3-4 systems (and other 4-3s), where the varied looks and confusing schemes imply a high degree of flexibility from all players, but in fact does not require as much individual diversity at key positions.
This defense is still vulnerable however. Receivers who can play an excellent inside release and run a corner route might target the area between the CB and the safety's cover responsibility.
Basically, a receiver aligned between the numbers and the sideline would move forward at an angle towards those numbers, then run straight towards the endzone once they've reached the center of the numbers (between the two digits). This signals either a dig route, post route, or corner route. Many safeties in other systems will try to line up underneath the receiver in order to prevent the receiver from effectively breaking in to the center of the field (which is the "dig" route). The corner route, however, will have the receiver break back out towards the sideline, usually with the safety a half-step behind.
In these situations, where the receiver releases inside without pressure from the CBs, the CB is supposed to sit inside of the receiver 's route (between the receiver and the QB) to play the intermediate or short zones while also clogging the passing lane for the receiver who just released inside. This should theoretically allow the safety some wiggle room in covering the receiver if that receiver decides (about 10-12 yards in) to attack the corner instead of the post. This works most because the quarterback will be forced to throw over two players (the safety and the corner).
In the Tampa-2, the safety should ignore the possibility of the dig, because if the receiver breaks inward at around 10 yards, the middle zone backers should pick them up. This is quite the responsibility, however and will require strict adherence to the system.
The system is also vulnerable to intermediate gains from slant routes (designed to exploit the matchup between the receiver and the linebacker) or by flooding zones (trip sets and smash routes—routes that require receivers to read deep zones—are pretty adept at this).
Some teams will further test the discipline of the safeties by sending 4 receivers to attack deep zones with different timing in their routes. Safeties that are too willing to cheat towards the middle of the field will get burned. Just like in the dig situation, if the safety decides to cover the first receiver to enter his zone, he may find himself giving up a play to another receiver.
This means that the system, in order to be successful in the long run, will also need disciplined safeties and middle linebackers who can pick up on tight end or slot vertical routes.
That's the Tampa-2 in a nutshell. It's designed to take advantage of the strengths of the Cover-2, which emphasizes a quick pass rush and containing big plays, while also reducing or eliminating its weaknesses, like overburdened MLBs and NTs and open sidelines and/or seams. It loses some of the focus on timing, but this was an inevitable casualty of the "Illegal Chuck" Rule (which this defense may be responsible for, as its other moniker is the Mel Blount rule). Instead, it's designed to limit mistakes, discourage big plays, and key up a punt.
Hopefully this has been as fun for you reading it as it has been for me writing it. That's it for the Tampa-2.
Thanks to Ron Jaworski and his book Games that Changed the Game and Matt Bowen over at National Football Post for unwittingly giving me the tools I needed to write this post.