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mesaSteeler
09-08-2010, 09:29 PM
Guide to N.F.L. Defenses, Part 3: The 4-3 Front Continued
By JENE BRAMEL
http://fifthdown.blogs.nytimes.com/2010/09/08/guide-to-n-f-l-defenses-part-3-the-4-3-front-continued/?pagemode=print

(See URL for diagrams that go with the article. - mesa)

Jene Bramel writes for Footballguys.com. You can also follow him on Twitter and reach him at bramel@footballguys.com.

The second installment in this series looked at the historical evolution of the 4-3 front, from Greasy Neale, Tom Landry and Steve Owen through the A.F.L. and its Odd Front 4-3 through the aggressive, undersized Miami front made popular by Jimmy Johnson and others. But there’s more to the 4-3 timeline. Another innovation was just beginning to blossom during the heyday of the Doomsday Defense and while Johnson was beginning to make his defense work with Oklahoma State in the 1970s. The innovation became so popular during the last decade that Tim Layden of Sports Illustrated once quoted Jim Schwartz as saying that 30 of the league’s 32 teams had some variation of it in their defensive game plan every week. That innovation would become known as the Tampa-2.

Cover-2

The Tampa-2 was built from a defensive coverage system that has been a part of defensive playbooks since coaches first drew up schemes with four defensive backs – Cover-2. Before breaking down the history and specifics of the Tampa-2, it’s worth a brief look at Cover-2 and a few other associated coverage definitions.

Cover-0: Man coverage without help.

Cover-1: Man coverage with a single deep safety playing “centerfield.”

Cover-2: Zone coverage with two safeties responsible for their own deep half of the field. Sometimes called “Two Deep” coverage.

Cover-3: Zone coverage with two corners and a safety responsible for a deep third of the field. Sometimes called “Three Deep” coverage.

Cover-4: Zone coverage with two corners and two safeties responsible for one quarter of the field. Sometimes called “Quarters” coverage.

Those definitions are simplistic, as teams will sometimes use three deep defensive backs and assign two to one deep half and one to the other (quarter-quarter-half coverage), and any combination of corners or safeties can combine to play the above coverages.

Here’s a diagram of the zones and responsibilities of the back seven in Cover-2.

Compared to the physical tasks of man coverage, Cover-2 may look simple to execute. It’s not. The linebackers must be disciplined enough to anticipate routes in their zone and stay in the probable passing lanes rather than playing too close to any single receiver. The corners must be aware of how many receivers are running routes to their side of the zone. In the way that a quarterback moves methodically through his receiving options, the Cover-2 defensive back has his own set of progressions to follow to prevent miscommunication and a big play. While the corner will often pass off a deep WR after he reaches a certain depth, there are situations where a corner must still get back to the deep sideline.

When well executed, Cover-2 forces a team to string together many successful short passes and prevents big plays. It’s the definition of a “bend but don’t break” system. However, there are weaknesses in any defensive system and the Cover-2 is no exception.

1. Cover-2 teams must have talented safeties and an elite pass rush. Each safety has to be able to cover an entire half of the field. They need range, closing speed, tackling skill and enough run-pass recognition ability not to get fooled by play-action. It’s extremely difficult for one defensive back to handle the deep middle and the deep sideline. Having an average safety behind a poor pass rush that gives the quarterback time to wait for the deep routes to develop is a recipe for disaster.

2. The Cover-2 can also be beaten by flooding one side of the zone with multiple receivers running routes on multiple levels or multiple receivers all running vertical routes. Force the safety, corner or outside linebacker to make decisions on which receiver to cover, and one route may be left open.

3. Cover-2 teams, by definition, put only seven players in the box and are susceptible to the run. They hope to successfully take away the run without dropping a safety into the box. A team that wants to run Cover-2 because their corners struggle in man coverage but can’t stop the run with the front seven is in major trouble unless they have safeties who recognize a run quickly and can rush in to offer support from 12 yards (or more) off the line of scrimmage.

4. Cover-2 teams, by definition, can’t blitz a linebacker frequently. Pressure must come from the front four. As mentioned above, a Cover-2 that can’t generate pressure goes from a bend-but-don’t-break style of play to one that gives up big plays in bunches when the deep routes come open downfield.

Tampa-2

Tony Dungy had been a converted quarterback turned defensive back playing for the Steel Curtain under Bud Carson. He watched Carson use his athletic linebackers and physical defensive backs in zone coverage behind a devastating four-man rush in the 1970s. He was struck by Carson’s idea to drop his middle linebacker into the deep middle to assist his safeties in coverage while allowing his quick and instinctive outside linebacker to assume more underneath responsibility.

Monte Kiffin had successfully adapted the 4-3 Under defense while a defensive coordinator at Nebraska and Arkansas to aggressively stop the run and generate a strong pass rush with a read-on-the-run philosophy. Collaborating with Floyd Peters, another believer in the 4-3 Under, with the Minnesota Vikings in the late 1980s, Kiffin helped make stars out of DT Keith Millard and DE Chris Doleman.

In 1992, Dungy and Kiffin found themselves on the same defensive staff in Minnesota under Dennis Green. You can imagine the discussions in the Vikings’ coaching offices. Dungy had seen firsthand how dropping the middle linebacker into the deep middle addressed many of the coverage weaknesses in the Cover-2. He also well knew what kind of defensive linemen it took to make the system successful and knew that the Stunt 4-3 that drove much of the success of the Steel Curtain was hard to run without four elite linemen. Running the 4-3 Under had generated nearly 40 sacks in one season for Kiffin’s duo of Millard and Doleman. Pairing the 4-3 Under (and Over) with the Carson Cover-2 tweaks seemed a perfect match.

The marriage of those two concepts in Minnesota became the foundation of the Tampa-2.

First, it’s worth noting that the Tampa-2 really isn’t a Cover-2 at all. Dropping the middle linebacker into deep coverage essentially morphs the zones into a three-deep look. Also, in addition to “sending the Mike down the pipe” and using under and over fronts, Dungy and Kiffin often dropped their corners off the line of scrimmage more often than having them rolled up at the line to re-route a receiver at the snap. That allowed the freedom to disguise coverages (the Tampa-2 wasn’t an every-down defensive call), roll defenders more easily to protect zones during rare blitzes and make it more difficult to block his corners (who were often the force players) when the offense ran the ball.

Dungy and Kiffin worked on their new scheme in Minnesota, and parlayed their success into a head coaching/defensive coordinator partnership in Tampa Bay. There, the duo inherited Warren Sapp and Derrick Brooks, Hardy Nickerson and John Lynch, all very well suited for their new scheme. In subsequent seasons, they added Simeon Rice, Ronde Barber and Donnie Abraham. The rest is history – nine consecutive seasons finishing among the league’s top-10 defenses, seven of them in the top five, a Super Bowl title in 2002 behind the league’s top-ranked defense and a far-reaching web of assistant coaches successfully taking the scheme around the league. At one time, 25 percent of the teams in the N.F.L. had head coaches or coordinators who were connected to the Buccaneer defensive coaching staff of the mid-1990s. It’s a coaching tree rivaling that of Bill Walsh or Bill Parcells.

How the Tampa-2 Made Stars of Warren Sapp, Derrick Brooks and Ronde Barber

The first installment in this series discussed Warren Sapp’s great success as the undertackle (3-technique tackle) in the Tampa-2. The under (and over) fronts that isolated Sapp one-on-one against a guard were a great fit for Sapp’s skills. But Sapp wasn’t the only player to benefit from the tweaks that made the Tampa-2 system. Certainly, Derrick Brooks and Ronde Barber had the talent to become All-Pro performers. But, like Sapp, they were put to their best use under Dungy and Kiffin.

1. The ‘under’ front protects the WLB well.

As can be seen in the diagram above, if the nose tackle engages the center at all, the weakside backer is free to flow to the ball after ensuring that his gap (the weakside center-guard gap, or A gap) isn’t threatened. With the SLB and MLB dealing with potential blocks from the TE, FB and an OL, the WLB will be in position to make a lot of plays.

2. Ballcarriers are “spilled” toward the WLB.

The Dungy-and-Kiffin philosophy preaches a turn back or spilling concept in run support. That is, a defender taking on a block knows where his most likely help will be and turns or spills the ball carrier in that direction. Since the WLB is often clean in an under front (and in certain variations of the over front), he’s frequently the teammate to whom the running back gets sent.

3. The WLB has more coverage opportunity than in other systems.

Traditional 4-3 schemes leave most of the man coverage responsibilities to the strongside linebacker or strong safety. The WLB needs to watch certain routes on early downs and will frequently defend a screen pass, but doesn’t usually make bunches of tackles or on-ball plays in coverage. With the underneath zone responsibility including some of the area vacated by the MLB who drops toward the deep middle, the WLB in a Tampa-2 4-3 gets more coverage opportunities. It’s not uncommon for the WLB to read a quarterback coming to a receiver over the middle and jump the route for an interception.

But it’s not just the weakside backer that gets more opportunity to make a difference in the Tampa-2. Like the Cover-2 zone cornerbacks that came before them, the corners in Tampa-2 schemes often get their jerseys dirtier than their counterparts in other schemes and routinely find themselves near the top of the league’s corners in tackles and big plays. The turn and spill concept also benefits the corner, as the corners are often the “help” when the front seven can’t make the tackle. The play-side corner gets the bulk of the extra business – often the strongside corner – but both corners may be the force player in run support as often as the safety. Also, because Tampa-2 corners play off the ball further than their traditional Cover-2 colleagues, they’re able to avoid blocks more easily on rushing plays and read and break on the ball more cleanly on underneath routes. Many of Barber’s big plays and high tackle counts are attributable to the nuances of the Tampa-2.

The Tampa-2 has lost some of its luster in recent years. Like any other defensive trend, it becomes harder to find an elite edge rusher, a 3-technique tackle, an athletic cover MLB and a physical corner when half the league wants them. But offensive coordinators can still beat the Tampa-2 with an athletic group of receivers in a spread offense. Fans of the Washington Redskins probably remember the long touchdowns of Terrell Owens down the sideline and Jason Witten over the middle when MLB London Fletcher fell victim to the pressures of multiple vertical routes a couple of seasons ago. But the Tampa-2 will never go away as a coverage scheme. It’s aggressive but conservative and forces quarterbacks to be very precise with their throws down the sideline or over the middle to beat it.

Though the Tampa-2 variation may be in decline around the league, the 4-3 Under (and Over) is still a major part of many teams’ defensive playbooks. Almost every 4-3 team uses the Over, and a handful play an under front regularly. The 4-3 Miami front we discussed in the last installment is a variation of the 4-3 Over. This season, Pete Carroll will use the 4-3 Under liberally, including a variation that will look like a 3-4 front to many.

4-3 Under and the Elephant Rusher

Carroll worked on the same staff with Kiffin at Arkansas and with the Minnesota Vikings and claims Kiffin as his primary defensive influence. Along with the 4-3 Under, Carroll will be using a pass-rushing variation that was first popularized by George Seifert in San Francisco. Looking to create mismatches anywhere he could against opposing offensive lines, Seifert allowed his weakside defensive end to move around his defensive formation to rush the passer from either side of the defense from a two-point stance. Players like Charles Haley, Chris Doleman, Rickey Jackson and Tim Harris filled this “Elephant” role with great success.

With the Elephant rusher in a two-point stance and the strongside linebacker usually near the line of scrimmage as another capable pass rushing option, these defenses look like a 5-2 or 3-4 front.

It’s somewhat of a semantic argument because there will be four players in a two-point stance behind three down defensive linemen, but this front is more like a 4-3 than a 3-4 because of how the three linemen line up. The lineman to the inside of the Elephant rusher is aligned as a 3-technique, something that you won’t see in a base 3-4 set. This look is essentially a 4-3 Under with a standup defensive end.

In the next installment, we’ll delve more deeply into the semantics and variations of the 3-4. We’ll consider why one longtime offensive coordinator questions whether the majority of the league’s current 3-4 fronts are “true” 3-4 fronts and why the 3-4 continues to gain favor around the N.F.L., just two decades after it was nearly out of the league entirely.

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