The Champions of the NFC

On January 24^th, the Carolina Panthers hosted the Arizona Cardinals in the NFC Championship game. The two top seeds in the NFC, both were minor surprises when they outperformed established contenders Green Bay and Seattle, knocking both those teams out in the previous round. And after a season that saw the two combine to go 28-4, they met for the chance to represent the NFC in the Super Bowl.

The game itself was kind of a disaster, with Carolina winning 49-15. But far more interesting than the game itself is what has come since. Because in the 11 games these two teams have played since they have combined to win only 3, and both sit in the bottom half of the NFC with a lot of work ahead if they hope to make the postseason again.

The struggles of these teams have been surprising, but looking back it isn’t hard to see the warning signs. Both teams found success in similar ways in 2015, and both are facing similar problems this year. These teams blitzed the league in 2015 with aggressive, high variance strategies, and both are seeing the downside of those tactics a year later.

Offense:

In a lot of ways the two most productive offenses in the NFL last season had very little in common. Arizona was a traditional team with a traditional quarterback, the veteran Carson Palmer having the best season of his career under veteran offensive mind Bruce Arians. Carolina ran an offense that takes a great deal more from the modern trends in the NFL. With an extremely mobile quarterback, they spread the field and attacked from the shotgun with an innovative scheme of zone read runs and run-pass options. Cam Newton led the league in rushing yards by a quarterback, and he finished fifth among all rushers with ten touchdowns on the ground.

On the surface these two teams had very little common offensively, but they were united by a simple philosophy in the passing game. And that philosophy was to chuck the ball down the field. Palmer and Newton finished first and third respectively in yards per completion, attacking down the field on a consistent basis to speedy deep threats like John Brown and Ted Ginn.

Throwing deep can be an effective strategy in the NFL, as evidenced by the success these teams had a year ago. Completion percentage drops the farther down the field a pass goes, but not by as quickly as yardage rises, and yards per attempt increases the longer the attempted pass is. Touchdown rate and interception rate both rise as well, but the expected point gain from a longer touchdown is worth more, and the cost of an interception is lower farther down the field.

Mathematically speaking, deeper passes produce more value than shorter ones. And this philosophy found a great deal of support in the success of Arizona and Carolina a year ago. The two best teams in the NFC were the two that attacked down the field most frequently, suggesting that NFL teams should play more aggressively on the offensive side.

That approach has hit a bit of a snag this year, as the downsides have reared their ugly head. On an average basis, deep passes produce more value than shorter ones. But a pure average neglects the extremely important statistical concept of variance. Aggressive play calling is worth more over a large sample, but in a small number of tests the spread in outcomes can be extremely wide, leading to either inappropriately positive or inappropriately negative outcomes.

This is a particular issue in the NFL, where the short 16 game schedule inevitably magnifies the effects of high variance outcomes. A year ago it worked in the favor of these teams, leading to better than expected finishes. And so far this year things have reversed, causing them to struggle to win games.

To understand why deep passes are so much more volatile, we need to break plays into their component parts. Let’s start by looking at one of the most consistent offenses in the NFL: the New England Patriots.

Over the past five years the Patriots have constructed an offense almost impervious to random chance. By spreading the field and attacking through a quick passing game, they negate a great number of tools the defense has to counter their attack. Based on the presnap alignment of the defense, Tom Brady breaks the play down into a couple simple reads that allow him to make his decision immediately off the snap of the ball. He gets the ball out of his hand quicker than any other quarterback in the league, and he delivers a short throw that gives the defense very little time to react to the flight of the ball. As long as his receiver can create some separation off the snap, the play is going to be successful.

Obviously this strategy is heavily dependent on Tom Brady, and there are very few quarterbacks that can pull this off with any sort of success. But the fact that he is able to do this allows the Patriots to simplify their offense beyond what most NFL teams can do. The success of the play depends almost entirely on Brady’s decisionmaking and accuracy, with only a small component by the wide receiver to create separation before the catch.

Compare this to the deeper routes run regularly by Carolina and Arizona. These plays take a long time to develop, and they involve many more moving pieces than New England’s. The quarterback still has to read the defense and make an accurate throw, but now there is more burden on the receiver to create a wider window, and to adjust to the ball while it’s in the air. There is more that the defense can do to mix up their coverages, and, most significantly, there is more a pass rush can do to disrupt the play.

If every piece of the play clicks, a deep pass produces a much better result than an underneath throw. But if any one of these pieces breaks down, it is doomed to failure. A year ago both these teams found remarkable consistency at every level of their offense. The quarterbacks delivered accurate throws, the receivers made great catches (for the most part…cough…Ted Ginn…cough), and the offensive line kept their passers upright.

Things haven’t worked out as perfectly this season. The elevation of Kelvin Benjamin and Devin Funchess in Carolina has left them with fewer speed receivers who can beat the defense over the top. Injuries to Newton and Palmer have limited their abilities to deliver the ball accurately. And both teams have struggled to protect the passer. Last year Arizona and Carolina gave up sacks on 4.6 and 6.2 percent of pass plays respectively. This year those numbers are 6.2 and 6.6.

Everything that could have gone well for these teams on offense a year ago did, and they dominated the league because of it. But their strategies left them vulnerable to small breakdowns that have dropped them from the top of the league to below average offensive units.

Defense

 

The story on defense is similar, if not quite as easily paralleled between the two teams. But teams have fallen victim to high variance approaches that benefited them a year ago, and even though the specific problems are different, the central philosophies of these teams have left them in similar difficult positions.

On Arizona’s side, the story of the defense is very similar to that of the offense. From top to bottom the philosophy of their team seems to be to play as aggressively as possible, and on defense that means blitzing the hell out of the opposing quarterback.

Arizona has been the most blitz-happy team in the league since Arians got there, and that has remained true this season. And they actually have been getting home, ranking third in the league with 18 sacks through the first three weeks. The real problems have appeared on the back end however, where their ability to lock down receivers man to man has disappeared.

Patrick Peterson is still playing at an elite level, but outside of him the secondary in Arizona has been shaky over the first few weeks. Rookie Brandon Williams looked every bit as outmatched as you would have expected from a third round pick, and he was benched for Marcus Cooper, a Kansas City castoff.

Cooper has played well since entering the lineup, and he gives them hope for improvement, as does the continued health of Tyrann Mathieu. At full strength he is a nightmare in the slot, a large part of the Cardinals posting top 5 DVOA (a Football Outsiders metric based on play by play success adjusted for level of competition) in 2015 against third receivers. They are 27^th in the league against those same receivers this year, but they have to hope that will improve as Mathieu gets healthier.

But even if he does get better, the Cardinals have to consider changing their defensive philosophy. The injuries to Mathieu have revealed just how dependent their defense is on him, and they might want to construct something a bit sturdier going forward. Their pass rush is succeeding now for reasons beyond just the blitz, and it would serve them to back off to take some pressure off their secondary.

Carolina is a slightly different case, but they too have fallen victim to placing too much emphasis on something that was due for regression. While not a blitz heavy team, the Panthers still found success pressuring the quarterback despite a lack of talent on the edge. In their case, the pressure came from the interior of their defensive line, with star tackle Kawann Short producing 11 sacks to lead the team.

Interior pressure is the best sort of pressure in the NFL. Collapsing the pocket from directly in front of the quarterback does more to disrupt him than pressure from the edge, and it can even alter quick hitting plays like the ones I discussed the Patriots using above. However, it is also the most difficult sort of pressure to apply, one that is subject to a great deal of volatility and easily accounted for by schematic adjustments by opposing offenses.

Short was the star of Carolina’s front last year, contributing a rare double digit sack season from a defensive tackle. And they pegged all their hopes on him being able to repeat this performance, despite plenty of evidence indicating just how difficult this is. In 2004 and 2005 Roderick Coleman of the Falcons put up 11.5 and 10.5 sacks. Since then no defensive tackle has managed consecutive double digit sack seasons. Not Ndamukong Suh, not Gerald McCoy, not Geno Atkins. In an era of elite interior pass rushers, it still is incredibly difficult to consistently produce as an interior pass rusher.

And so far this year Short has failed to even come close to last year’s production. He has only a single sack through five games, and the Panthers have fallen to middle of the pack in total sacks, after finishing last season ranked sixth in the league.

This wouldn’t be as big an issue if Carolina hadn’t bet the fortunes of their defense on the strength of their front. After deciding that they didn’t feel like paying Josh Norman to be an elite corner, they let him go, leaving them with the duo of Zack Sanchez and Bene Benwikere (since released!) starting at cornerback.

The dropoff has been clear. The difference is most obvious against number one receivers, where they have dropped from having the third best DVOA to the 26^th. But similar trends can be seen across the board. Against third receivers they’ve dropped from third to 25^th, and against tight ends they’ve fallen from the best team in the league to the fourth worst.

Part of this can be explained by the reshuffling in their secondary, but these struggles across the board have more to do with their failure to get after the quarterback. For years now Carolina has operated with the philosophy that they can play without elite talent on the back end of their defense, assuming they will just dominate up front. Now that assumption is being proven wrong, and the vulnerabilities of their defense are being revealed.

Carolina and Arizona posted the two best records in the NFC last year, but it shouldn’t be a shock that they have struggled to start this year. Their success last year represented the best case scenario of several high variance strategies, covering the fragility and thinness of their rosters with unusually fortunate outcomes. Now that things have started to break down, we’re seeing these teams for what they are. High upside and high downside, with a chance to blow out any opponent or watch the bottom drop out beneath them on any given Sunday.