Defense – Total American Football

Overplaying the cat and mouse game

Aaron Rodgers, Bears, Cover 1, Cover 2, Cover 3, Defense, Defensive philosophy, Packers, Pass defense 4 Responses »

Nov 142014

Overcomplexity in a defense can be dangerous (see here). The Chicago Bears gave us another example, this time in the context of excessive pre-snap checks.

A national television audience witnessed the six passing touchdown first half by Aaron Rodgers. Perhaps the most notable of the six was Jordy Nelson’s 73 yard touchdown reception. The play was – as was obvious to the naked eye – a blown coverage. But why was the coverage blown?

Before the snap, Aaron Rodgers performs a hard count, attempting to draw the Bears into the neutral zone. As he does so, the Bears show blitz, with six defenders on or near the line of scrimmage, and a seventh (linebacker Lance Briggs) creeping in that direction. Safety Chris Conte follows a receiver in motion from left to right, showing (or at least feigning) man coverage.

After the hard count and the motion, Rodgers stops, turns to face his receivers to the right (in a trips formation), and signals while making a call. At the same, we see Briggs turning to motion and call to his fellow defenders.

Rodgers turns to the line as Briggs yells to his teammates

The defenders begin to move, as Briggs continues shouting orders and motioning.

Moments before the snap, we see Bears defenders backing away from the line of scrimmage. Conte backs up, showing (or feigning) zone.

The structure of the defense becomes clear as soon as the ball is snapped. There is one high safety, and cornerbacks in press. There are several options for what the Bears might be trying to play. The most likely are cover 3 or man free. In either of those options, the press cornerbacks would be covering any vertical pattern by the #1 receiver, who they are aligned over.

Cornerbacks in press, free safety deep in the middle of the field.

In the cover 3 or man free scenario, the answer to who blew the coverage is clear: the cornerback. There is no doubt that he played as if he had help over the top, forcing the receiver inside while jumping on a shallow route. This is classic cover 2 cornerback play.

The cornerback has forced Nelson to take an inside route, while eyeing a receiver who threatens the flat - classic cover 2 cornerback play.

The cornerback has forced Nelson to take an inside route, while eying a receiver who threatens the flat – classic cover 2 cornerback play.

Other (less likely) possibilities are (1) that Conte should have retreated in cover 2. This is not likely, because the free safety did not shade to the other half of the field. Alternatively, (2) the free safety may have been the guilty party, playing a version of cover 2 where he is over the top to Nelson’s side, while the opposite cornerback manned the other deep half, or (3) a version of cover 3 where the middle linebacker (who is dropping deep on the play) takes the deep third.

Nelson catches the ball. The free safety has not reacted from his deep middle zone, the cornerback trails from his cover 2 positioning, and the middle linebacker chases from his zone.

For the purposes of this post, knowing who was responsible for the coverage bust is immaterial. A particular player can be blamed, but the point is – as a coach – that someone did not get the message. “Not getting the message” is an inherent risk in playing such a cat and mouse game, and the Bears got burned.

The benefit that the Bears were striving for is clear. The opposing quarterback has just changed the play in order to beat our defense, so we will change our defense in order to frustrate his intentions. And there is no doubt that the caliber of quarterbacks in the NFL requires a defense to show different looks, lest a great quarterback such as Rodgers pick them apart. On paper, it makes sense to attempt to frustrate Rodgers in this fashion, especially towards the end of the play clock, when Rodgers cannot audible again. But the game is played on a noisy field in front of thousands of fans, where communication is difficult, and the draining play clock also means that the Bears have little time to make their adjustments. Players need to call and receive the new front/blitz/coverage, adjust their alignments, and mentally digest the information – all in the final few seconds before the snap. It can – and does, on many occasions – work. But when it doesn’t work – as is often the case – it can lead to catastrophe for a defense. The defensive coordinator must always consider this balancing, essentially asking himself “Is the benefit of confusing the offense worth the risk of confusing ourselves?” There is a fine line between creating confusion for the opposition and creating confusion for yourself, and in this case, the Bears beat themselves before the ball was put into play.

The dangers of an overcomplex defense

49ers, Blitzing, Defense, Defensive philosophy, Saints No Responses »

May 032014

Aggressive defenses with multiple fronts and complex blitz schemes create problems for offenses due to their multiplicity and unpredictability. These defenses are high risk, high reward, and high difficulty. They require skillful play calling, as “choosing wrong” in terms of pressure leaves the defense susceptible to huge plays. Sound, simple defenses – while lacking the same attacking and confusion creating abilities – are not as susceptible to such breakdowns. In other words, aggressive defenses are “boom or bust,” and too much complication can lead to breakdowns at inopportune times.

Such was the case during the 2012 divisional playoff game between the San Francisco 49ers and the New Orleans Saints. With 2:18 left in the game, the 49ers trailed 23-24, facing a 3rd and 7 at the 27 yard line. They came to the line with Frank Gore as the lone back, and immediately shifted to an empty formation, with a tight end and two receivers to the right, and two receivers to the left.

The Saints were an aggressive, blitzing team under coordinator Gregg Williams. This style helped lead them to a Super Bowl title in 2009, a year in which they were second in the league with 35 defensive takeaways. 2009 showed the “boom” of the defense, while the Saints were about to experience the “bust” in San Francisco.

Above, note the Saints alignment. It is clear that they have called a blitz in an obvious passing situation in order to put pressure on Smith. It is no mystery where the blitz is coming from. There are FIVE defenders near the line of scrimmage between right tackle Anthony Davis and Frank Gore in the slot. While it isn’t clear which of the five will rush the passer – such is the benefit of the aggressive defense – almost half of the defense is concentrated near the line of scrimmage in an area covering not more than ten yards. Not surprisingly, this leaves other areas of the field open to exploit.
We also see wide receiver Kyle Williams in motion. Cornerback Patrick Robinson follows him to the inside. Herein lies the most interesting aspect of the play. As the play unfolds, Robinson continues running towards the center of the field – even as the ball is being run in the opposite direction. He will run himself to the opposite hash as Alex Smith runs down the sideline for a touchdown. Nothing better illustrates the problem with an overcomplicated defense. Because it requires players to execute so many different schemes and coverages over the course of the game, they must devote brain power to performing many different assignments throughout the game. This means that they often cannot play without thinking, which causes them to lose sight of what is important – the ball. Such is the case here, as Robinson runs in a direct path away from the ball.

There is no misdirection as the play unfolds, above. Kyle Williams cracks the defensive end – a staple play from Pop Warner on up. Left tackle Joe Staley pulls to lead the play. Notice the five defenders to the right of the formation that we noted before the snap. They are wasted from the snap of the ball, with no chance to make a play. Cornerback Robinson is well on his way to the opposite hash. A simple quarterback sweep, and eight Saints are on the wrong side of the field. Of the remaining three, two are on the hash being cracked to the inside, and the third is Robinson sprinting in the wrong direction. The 49ers have almost half the field at their disposal, with Joe Staley leading the play and no one in sight for him to block.

Above, we see Robinson on the hash, and the remainder of the Saints in pursuit.

Joe Staley’s cut block seals the play.

Defensive coordinators must balance the benefits of aggressiveness and unpredictability with the necessity for execution. Many multiple, attacking defenses have been successful and will continue to find success, but coaches must ensure that the players are not so assignment driven that they lose sight of what is most important: stopping the ball. As the Saints showed against the 49ers, this issue exists even at the highest level of play. While it is easy to blame a player for an assignment mistake, a coach must also look to himself, and ask whether he has added more than his players can handle. Even if a player botches a seemingly “basic” defensive (i.e. a safety not covering his deep half of the field in cover 2), the coordinator must ask if this is a manifestation of the player’s inability to play without thinking as a result of overcomplexity. The danger of overcomplexity isn’t only seen in major plays of the game; often, it is in the moments of tentativeness that add up throughout the course of a game to act as an invisible sabotage to playing aggressive, winning defense.

Improving cornerback play with Cover 3 and Cover 4 press; the rise of Richard Sherman, Darqueze Dennard, the Seattle Seahawks, and the Michigan State Spartans

Cover 3, Cover 4, Darqueze Dennard, Defense, Michigan State, Pass defense, Richard Sherman, Seahawks 4 Responses »

Apr 052014

The Seattle Seahawks defense and the Michigan State Spartans defense were the darlings of the NFL and NCAA, respectively, in 2013. Despite some schematic differences, these defenses shared important similarities. Both were simple in comparison to their peers, executing their base defense to perfection, allowing their defenders to “play fast” because they had no doubt about their assignments. The defenses were also each led by a breakout performer at cornerback – Richard Sherman for the Seahawks, and Darqueze Dennard for the Spartans.

Contrary to popular belief, neither cornerback is a man to man bump and run player. The Seahawks and Spartans are both zone teams (the Seahawks primarily cover 3, the Spartans primarily cover 4), with the cornerbacks aligned in a press position. They appear to be in man coverage because, if the receiver runs a pattern deeper than 10 yards (approximately), the cornerback stays locked on that receiver in man coverage. If the receiver runs a short pattern, the cornerback is often in position to take this pattern away once the ball is in the air by their pre-snap alignment, which adds to the man to man illusion. But the short patterns are not their responsibility.

This may seem like a minor distinction, but it pays major dividends. Instead of needing to worry about every pattern the receiver might run, the cornerback can focus on re-routing the receiver (helping out all aspects of the defense) and turning and running to take away deep patterns. This is a perfect defense for fast, physical corners such as Sherman and Dennard.

Take Sherman. A tall, lanky track star at cornerback, his theoretical weakness would be against double moves and short, quick patterns. This is because a taller player at cornerback with longer legs has a comparative disadvantage when making quick, fast cuts and redirections.

The Seahawks defense means, however, that Sherman merely needs to use his length to throw the receiver off his pattern, and his speed to turn and run if the receiver runs a deep pattern. His 6’3”, spidery frame, track jump background, and intelligence make him the ideal athlete for this technique.

He also illustrates the Seahawks’ rise to prominence. Much like the Oakland Athletics who Michael Lewis chronicled in Moneyball, the Seahawks found undervalued athletes late in the draft who fit their system to perfection. In Moneyball it was specifically about finding players who had patience at the plate; in Seattle it was about finding tall, physical defensive backs late in the draft who could execute Seattle’s defense. Richard Sherman was a number one overall pick in terms of fit for the Seahawks, though in reality he was picked in the 5th round.

Denard, too, was an underrated prospect who rose to prominence due to a perfect mesh of scheme and athleticism.

No example of this technique is better than Sherman’s game clinching play against the San Francisco 49ers in the 2013 NFC Championship game.

In diagram one (below), we see Sherman lined up in press on Michael Crabtree to the bottom of the screen. On the opposite side, of the field, Byron Maxwell (Seattle’s other big, physical cornerback) is lined up in press on Quinton Patton. Also note that Seattle is in a two high safety alignment, which differs from their base cover 3 look, but is similar to Michigan State’s base alignment.

At the snap of the ball (below), Sherman gets a hand on Crabtree and turns to run with him. It looks like man coverage. But look to the top of the screen. Maxwell is also bailing deep on the play, as if he is covering Patton deep. Patton, unlike Crabtree, stands still at the line of scrimmage. Sherman – while appearing to be in man coverage – knows that if Crabtree stops short, Sherman can continue deep, because linebacker Malcolm Smith is underneath Crabtree’s pattern. Therefore, Sherman can focus all of his attention on sprinting downfield in defense of any deep Crabtree pattern.

The television broadcast camera made it appear that Crabtree had a step on Sherman. This was never the case. As we see below, Sherman was a step ahead of Crabtree the entire play. He has positioned himself perfectly – he will beat Crabtree to the spot should Crabtree continue on a fade (as is the case) and has inside leverage to undercut any deep in breaking pattern (such as a post or dig) that Crabtree might run. His ability to “sell out” on these deep patterns is made possible by the zone principles that let him play without hesitation. We can see Smith – who will catch the interception – dropping in the underneath zone, ready to pounce on a short pattern. He was not occupied on the play by any other receiving threat, allowing him to drift farther back and eventually gather the Sherman’s deflection.

Also note that Maxwell has continued to bail deep (he is actually deeper than Sherman) and is now 14 yards away from Patton, who remained at the line of scrimmage.

Below, we see the moment when Sherman reaches the ball at its highest point, deflecting it to Smith for the game sealing interception. For the television camera, it appeared that Crabtree was behind Sherman. In reality, Sherman found the ball, slowed, and leaped to tip it, creating the illusion that Crabtree was behind him. Make no mistake, Sherman was not beaten on the play.

Cover 3 and Cover 4 press, pattern matching teams require a specific athlete at the cornerback position. The cornerback must be physical and skilled enough to jam a receiver at the line, and fast enough to run with that receiver on all deep patterns. The cornerback does not need the same short legged quickness that is required to guard fast twitch receivers in the short or slot game. This simplified role has allowed Mark Dantonio at Michigan State to build the top defense in the country with many lower tier recruits (Dennard, for example, was a 2 star recruit with no other BCS offers from a tiny high school in Georgia), and for Pete Carroll to build one of the greatest defensive backfields in the history of the NFL out of largely late round and free agent prospects. The ability to play fast breeds confidence, and has helped two elite yet overlooked athletes climb to the top of their game, bringing the rest of their respective defenses with them.