Denver remains No. 1 in the Football Outsiders DVOA ratings, but New England moves up to No. 2 and has taken over as our Super Bowl favorite.
07 Aug 2005
by Mike Tanier
You know man coverage: it's the way you played defense when you and your buddies played 4-on-4 football in the parking lot. As you might suspect, what starts as a pretty simple scheme ("you take that guy, I'll take this guy") becomes pretty complex by the time you reach the NFL level.
The strengths of man coverage are the same in the pros as they are in the sandlot: defensive assignments are relatively simple, limiting decision-making and allowing athletes to be athletes. But the weaknesses are also the same: the coverage is easy to read, and the fat kid has to cover somebody. Sure, the NFL's fat kids aren't asked to drop into coverage very often, but the opportunities for mismatches that favor the offense are all too ample: some slow linebacker vs. Tiki Barber, some rookie nickel defender vs. Reggie Wayne.
How do teams avoid mismatches? There are a variety of tactics at the defensive coordinator's disposal. He can assign double coverage, blitz, or keep safeties deep in a man-zone hybrid coverage. He can also vary the coverage responsibilities of the defenders, ensuring that a 250-pound linebacker isn't asked to cover Brian Westbrook on a deep seam route.
In standard man coverage, the cornerbacks take on the wide receivers, the strong safety matches up with the tight end, the strongside linebacker (Sam) covers the fullback, and the weakside linebacker (Will) takes on the halfback.
Or maybe not. While cornerbacks cover receivers almost all of the time, many coaches match up their defenders based on field locations. For example, the Sam linebacker would take the first receiver to head into the strongside flat, the Will linebacker the first receiver to enter the weakside flat. The strong safety covers the first receiver into the seam on the strong side. The middle linebacker (Mike) would then take on the second receiver to enter either flat or the seam.
In this kind of coverage (often called a pattern match), defenders are playing man coverage based on the zone the receiver attacks. If the tight end runs a shallow flat route (a few steps off the line and then a fade towards the sidelines), the Sam linebacker covers him. If the halfback streaks out of the backfield and runs a downfield pattern, the strong safety covers him. You can see the advantage when playing a team like the Rams: no defensive coach wants a fast safety covering Brandon Manumaleuna while a linebacker deals with Marshall Faulk.
Some teams use formation matches instead of pattern matches. Formation matches are useful when playing a team like the Chargers. With Antonio Gates lining up all over the field and going in motion before the snap, how do you cover him? In a typical formation match scheme, Gates would be covered by whichever safety lined up on his side of the field. If Gates goes in motion across the formation, he is picked up by the other safety. A running back may be the responsibility of the Will linebacker until he goes in motion and becomes a slot receiver. Once he is outside of the tight end, the Will stops covering him, and he becomes the responsibility of a safety.
Formation matches prevent the offense from using pre-snap motion to completely scramble the defensive formation. Imagine an offense starting in a two-back,one-TE set, then moving a tight end and running back into slot positions. If linebackers were covering both players, the defense could suddenly be left with two linebackers in open-field coverage while only one defends the "box" between the tackles. In a formation shift system, both slot receivers would be picked up by safeties.
Two players who were barely mentioned above are the middle linebacker and the free safety. What are they up to while everyone else is isolated against a receiver? Depends on the type of man coverage.
Man-1 (or "man free") means that the free safety is playing a deep zone. He is generally responsible for the middle third of the field, starting about 18 yards behind the line of scrimmage. Any receiver who runs a seam, post, or deep crossing route gets picked up by the free safety, effectively creating double coverage.
(One quick note: many teams barely distinguish between free and strong safeties anymore, so what we refer to as the free safety's duties could easily be either safety's job, depending on the system.)
The middle linebacker's responsibilities are more complicated. He usually must read the play to make sure that it is really a pass; if the offense runs a delay, draw play, or screen pass, the middle linebacker is responsible for the running back. Once he determines that the quarterback is setting to throw, the Mike linebacker usually sets up in a zone in the short middle of the field. Coaches stress that it's the Mike's job not just to help on crossing routes, but to make sure that any deep pass over the middle of the field is thrown high, giving other defenders a chance to converge.
The Mike linebacker can also blitz, but it's more common to send the Will or Sam linebacker, in which case the Mike covers a flat route or a running back. Because play action is such a weapon, the Mike is sometimes given double coverage responsibilities with the Will or Sam on a halfback. Imagine a play action fake off tackle to Edgerrin James. The Sam linebacker must react quickly to the run; as a result, he's out of position when Edge runs a circle route. Luckily, the Mike was assigned to pick up Edge.
In Man-2 (or "man under") coverage, both safeties play deep halves of the field in zone coverage. The Sam linebacker takes the tight end, the Will takes the halfback, and the Mike takes the fullback (or a pattern match system can be used). Because pro halfbacks and tight ends are so fast, Man-2 can be troublesome for base defensive personnel. But it can be very effective in a nickel defense, where one of the extra defensive backs can cover a tight end or halfback.
Man-2 is used frequently in the pros. It looks like Cover-2 at the snap, so it can confuse the quarterback a little. It provides de facto double coverage against deep receivers. When playing a team like the Rams, Man-2 keeps Isaac Bruce and Torry Holt under control, while covering Marshall Faulk man-up with a nickel back makes more sense than letting him run wild in underneath zones. One major drawback of Man-2: blitzing is very difficult, as some receiver won't be covered.
You don't see a lot of Man-0 (or "zero coverage") in the NFL; the Eagles and Chiefs use it often, but most teams don't. Many coaches (especially those of the Tony Dungy-Lovie Smith school) refuse to call a defense that doesn't include at least one deep safety. But if you really like to blitz, Man-0 is the coverage for you.
In many cases, Man-0 is part of a jailbreak blitz. Watch an Eagles game, and you'll see Brian Dawkins and Michael Lewis tight to the line of scrimmage, looking like dogs in the window of the steak house. Every receiver is covered one-on-one, and any defender with nothing better to do is attacking the backfield. Obviously, the defense is vulnerable to the deep pass, but Jim Johnson is usually pretty confident that the quarterback will be roadkill by the time a receiver breaks free.
What often looks like Man-0 coverage is often a zone blitz in disguise. The quarterback who comes to the line and sees no deep safeties is likely to audible into a deep route, assigning his running backs to block the blitzing defenders while a receiver streaks up the sidelines or the seam. But pro defenders are fast enough to drop into zones in a hurry, so what looks like a kitchen sink blitz may actually be an act of subterfuge: you can tell the difference if several defenders back off the line of scrimmage in a hurry the moment the ball is snapped.
Man-0 coverage also occurs when one or more receivers are double covered, usually by the safeties.
We saw an example of double coverage a few paragraphs ago: two LBs may be assigned to cover a running back so that they can also play run defense. But when we think of double coverage, we usually think of two guys working together to stop Randy Moss.
Double coverage takes many forms in the NFL. You will sometimes see bracket coverage, with one defender taking the star wideout at the line of scrimmage and another taking him 10-15 yards down the field. Bracket coverage looks a little like a Cover-2 zone, except that the first defender never peels off the receiver to defend the flat. Both defenders maintain high-low coverage throughout the receiver's route. Players like Moss and Terrell Owens sometimes warrant bracket coverage, but many coaches prefer schemes like Man-2 or rolling Cover-3 coverage that don't automatically tie up two defenders for one receiver.
Another variation is combo coverage, in which two defenders disrupt the star receiver's release. This can be effective against hard-to-jam receivers like Owens. After five yards, one defender stays with the receiver in man coverage, while the other takes on another assignment (picking up the first running back to enter his flat, for example). This technique can frustrate the receiver, who may never get into his pass route while battling two defenders, but it weakens the deep coverage against other receivers.
Triple coverage doesn't happen. When an announcer says "the quarterback threw into triple coverage," he's saying there were three defenders nearby. In Man-1, these defenders could be the man-up cornerback, the free safety, and the middle linebacker who read the play and took a deep drop. It could be bracket coverage, plus a free safety. It could even have been a zone. But not even Randy Moss gets three defenders.
A whole book could be written about the proper techniques for covering a wide receiver, from the correct stance at the snap to the footwork to the ways to read a pass route. What follows are some basics that cornerbacks are taught at the high school and college ranks, skills that are reinforced in the pros.
The Jam: There are several ways to jam a receiver on the line, depending on whether the receiver tries to break inside or outside of the cornerback. But the defenders are always taught to keep their feet shoulder width apart, keep their hands inside of their elbows, and to keep their hips open to the receiver. Defenders should never move forward to jam the receiver; instead, they should slide laterally to meet the receiver two or three yards down the field. A cornerback moving forward at the snap is begging to be burned.
The Cushion: Cornerbacks who aren't jamming the receiver at the line generally give a cushion of about eight yards. When giving a cushion, the cornerback must maintain some distance from the receiver until the receiver cuts, the ball is thrown, or the receiver is about 15 yards down the field. The receiver's goal in soft coverage is to eat up that cushion: to force the defender to stop backpedaling and turn around to run. A defender who turns before the 15-18 yard mark is vulnerable to every comeback, curl, and out route in the playbook.
Reads: In general, a cornerback watches the receiver in man coverage and the quarterback in zone coverage. But a cornerback in soft coverage is often told to read the drop of the quarterback. Three-step drops mean short routes, and a passer who is only dropping three steps will often stand straight up from under center and cock his arm immediately (when executing a longer drop, a quarterback will usually stay lower while he is digging with his feet to get backward momentum). The defender cannot spend too much time peeking into the backfield in man coverage, but if he can read the drop, he can react to a slant route and intercept a pass.
Run Support: Cornerbacks are paid for their coverage skills, but a cornerback who cannot fend off a block and tackle a running back can be a real liability to the defense. When a cornerback is suddenly blocked by his receiver, his job is to try to beat the receiver's block to the inside and constrict the running lane. He can use brute strength to do this, but most cornerbacks must use quickness to get inside and under the block of a bigger wide receiver. Ideally, the cornerback will slice through the block and make a tackle, but most coaches are satisfied when the cornerback works inside, gums up a running lane, and forces the ball carrier to venture even further towards the sidelines.
Coaches have developed a thousand variations on man coverage, zone coverage, and their hybrids, and new wrinkles are introduced every year. No matter how complicated the terminology or techniques get, the same basic principles apply. The defense must be able to cover up to five receivers, defend the whole field, pressure the quarterback, and avoid the long bomb at all costs. Basic man coverage schemes allow coordinators to keep extra safeties back, rearrange assignments, double cover, or blitz depending on the needs of the moment. In the super-complex world of football strategy, man coverage remains a relatively simple but highly effective tool.
This is the first part of a two-part series. An article on zone coverage will appear next week.
14 comments, Last at 11 Aug 2005, 2:58pm by Jason