Pass 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.

How man coverage can weaken run defense

Air Raid, California Golden Bears, Cover 1, Defense, Defensive philosophy, Man coverage, Michigan State, Offense, Pass defense, Play calling, Run defense, Run game, Seahawks, Tony Franklin No Responses »

Nov 082014

Many coaches and fans believe that a man pass coverage scheme leads to better run defense. This is because – the thinking goes – primary run defenders are given more freedom to attack the run with aggressiveness, while primary pass defenders focus on covering receivers. If the defensive coordinator is willing to play with limited help over the top, it also allows the defense to load the box to stop the run. For example, in a common “man free” scheme against a traditional two wide receiver set, the two cornerbacks lock up the wide receivers and the safety plays over the top, while the remaining 8 defenders can play close to the line to stop the run.

Such thinking has extended to defend spread offenses. Against a “spread to run” opponent, one strategy is to lock in man coverage on the receivers to take away quick patterns, while giving your team a numerical advantage inside the box. Because of this numbers advantage, the defense can be aggressive with run fits, blitzes, and stunts. The numbers advantage can often be achieved even while keeping two safeties on the field, because of pattern matching principles, which allow outside linebackers to stay closer to the box and safeties to play the run more aggressively (further explained below).

Man coverage principles can, however, weaken a run defense.

The primary reason is because it is very difficult for a defender to play man coverage and maintain proper run discipline and pursuit. With responsibility focused on a receiver, a defender is much more likely to be run out of a play by a receiver simulating a pass pattern. Edge defenders will have difficulty preventing the ball from being run outside when they also have to defend routes that take them inside. The offense can also more easily manipulate defensive alignment in order to break contain. For example, a trips formation to one side with a tight end on the other side may lead to only a linebacker standing between the offense and the sideline on the tight end side of the field. If the offense can break that contain (against a linebacker instead of a defensive back), they have a big play on their hands.

Enter California and their prolific offensive coordinator, Tony Franklin, against the Oregon State Beavers. Oregon State under Mike Riley is and continues to be one of the most sound and well coached programs in the country, consistently fielding rugged, overachieving teams. They came into the game with a strong pass defense that seemed to match up well against Cal’s powerful air attack. In this game, however, their man principles hurt their ability to stop Cal’s running game.

As one can see below, Oregon State lines up in a two safety shell against Cal’s four wide receiver (2×2) offensive set. The outside linebackers split the distance between the #2 receivers (the 2nd receiver from the outside) and the offensive tackles. The safeties play inside shade of the #2 receivers, while the cornerbacks line up in press coverage on the wide receivers.

What is not clear is whether the Beavers are playing true man coverage, or pattern matching principles. Pattern matching is a method by which particular defenders lock in man coverage against certain offensive patterns, while playing zone against others. For example, a typical pattern matching scheme is for the outside linebackers to cover any short out route by a #2 receiver in man coverage, while they would re-route any vertical stem by the #2 receiver, and then look to help in the flat. The safety would cover any vertical route (more than 7-10 yards) by #2, while the CB would cover any vertical route by #1. In many ways, pattern matching combines the best of both zone and man coverage – nobody has to cover every pattern, so they can be more aggressive against the run, while maintaining the benefits of man coverage against the pass. Teams such as Michigan State (which bases out of a 2 safety, cover 4 pattern matching defense) and the Seattle Seahawks (a primary 1 high safety [Earl Thomas, perhaps the best safety in the game], cover 3 defense) have built dominating defenses on such principles (see https://www.totalamericanfootball.com/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/ for an in depth explanation of how such principles aid cornerback play). Michigan State’s defense has – in particular – taken the coaching world by storm. Simply put, the Spartans have laid out a blueprint that allows safeties and linebackers to play the run aggressively (thus effectively creating a 9 man box) while having less fear of being burned in the passing game, because they do not have to cover every pattern by a particular receiver. The Spartans defenders are terrific at reading run or pass and reacting accordingly. Unfortunately for the Beavers, even if they were using such a pattern matching scheme (it is unclear if they were), they were much too quick to jump into man principles on any particular play against Cal. Franklin exploited this over-zealousness on many occasions, both on run/pass neutral downs and on obvious passing downs.

Whether or not the Beavers were playing man or a pattern matching zone on this play, their defenders locked in on receivers in man coverage as soon as those receivers ran their routes. When Cal ran the ball, Oregon State was left with little support.

Oregon State is lined up in a typical 2 safety shell, with safeties on the inside shade of the #2 receivers, OLBs splitting the distance between #2 and the offensive tackle, and the cornerbacks in press coverage. With the outside linebackers so close to the box, Oregon State would appear to have a numbers advantage against the run. Their front seven remains close to the ball (though both OLBs are slightly outside the box), while Cal only has 5 offensive linemen to block the interior, with no lead backs or tight ends to help counterbalance the Oregon State front.

Oregon State is lined up in a 2 safety shell, with safeties on the inside shade of the #2 receivers, outside linebackers splitting the distance between #2 and the offensive tackle, and the cornerbacks in press coverage. With the outside linebackers so close to the box, Oregon State would appear to have a numbers advantage against the run. Their front seven remains close to the ball (though both outside linebackers are slightly outside the box), while Cal only has 5 offensive linemen to block the interior, with no lead backs or tight ends to help counterbalance the Oregon State front.

Cal quarterback Jared Goff turns and immediately hands to running back Daniel Lasco. There is no pass fake from the backfield action (though Goff does fake setting up for a pass after he hands the ball to Lasco).

Cal quarterback Jared Goff turns and immediately hands to running back Daniel Lasco. There is no initial pass fake from the backfield action (though Goff does fake setting up for a pass after he hands the ball to Lasco).

After the ball is handed off, we see that the Beavers have already lost both CBs. Both have their backs turned, defending pass patterns. Even worse, their playside outside linebacker has turned his back to the ball, and is covering a slot receiver on a quick out route. Both safeties are eyeing the slot receivers.

After the ball is handed off, we see that the Beavers have already lost both cornerbacks. Both have their backs turned, defending pass patterns. Even worse, their playside outside linebacker has turned his back to the ball, and is covering a slot receiver on a quick out route. Both safeties are eying the slot receivers.

As Lasco reaches the line of scrimmage, the Beavers have lost their advantage. The playside outside linebacker is almost beyond the hash marks, still chasing the quick out route. The playside safety IS outside the hash marks, most likely looking to help with the vertical route being run by receiver #1 to his side. Both cornerbacks are completely removed from the play, as is the weakside safety, who is also likely to be helping with the vertical route by his #1.

Notice that the Cal offensive line hasn’t manhandled anybody – they simply put bodies on bodies. The Oregon State middle linebacker has filled his gap decently well – but there is no help from the playside outside linebacker or safety to squeeze the play, and Lasco easily scoots outside. No support means that nothing is squeezed to the middle of the field, effectively rendering meaningless any pursuit from the Oregon State front.

Lasco heads towards the secondary. The playside safety has now reacted, but – as with his middle linebacker – he has no help from his opposite safety, allowing Lasco to veer easily away from his pursuit.

As Lasco cruises into the end zone, neither the backside safety nor the backside cornerback has come into view – both have been occupied by the #1 receiver.

Every defense has its weakness. This post is not meant to say that man coverage and man principles cannot produce great defensive football. The aim of the post is to point out a (perhaps) hidden weakness in man coverage that many fans and coaches do not consider.

See the video here:

http://espn.go.com/video/clip?id=espn:11807066

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.