Daniel Jones Hasn’t Figured Out Zone Coverage Yet

In Week 7 against the Arizona Cardinals, New York Giants quarterback Daniel Jones dropped back to pass on third and 13 from his own 35-yard line. Faced with a four-man rush and seven defenders in coverage, Jones waited patiently — perhaps too patiently — for his receivers to complete their routes past the first-down marker. Feeling pressure on his left, Jones stepped up in the pocket and fired the ball downfield — right into the arms of Cardinals linebacker Jordan Hicks. Hicks was playing zone coverage in the hook/curl area of the field, and he was in the perfect position to step in front of intended receiver Golden Tate.

While it might be tempting to dismiss the mistakes of a rookie QB as growing pains, the interception wasn’t an isolated case of a young quarterback making a questionable decision. It turns out that zone coverage has been a problem for Jones since he took over the Giants starting job in Week 3. Six of Jones’s eight interceptions on the year have come against zone, and he’s averaging just 5.6 yards per attempt against the coverage — worst in the league. Jones has completed passes 1.7 percentage points under what we would expect of a league-average QB against zone, according to NFL Next Gen Stats, and his QBR is an anemic 27.5. More surprising, given generational talent Saquon Barkley at running back, is Jones’s QBR of 24.9 on play-action passes against zone, which places him 30th out of 32 qualifying quarterbacks.

Jones’s poor performance on play-action is a little strange because we might expect that teams would play more Cover 1 (a form of man coverage with a single high safety) against the Giants with Barkley in the backfield, a defensive formation that allows them to bring a safety down from deep coverage to help out against the run. Through Week 12, however, that hasn’t been the case. New York opponents are playing 50.4 percent man coverage vs. 49.1 percent zone, which is almost exactly league average. The team would likely benefit from opponents playing more man coverage to match up against Barkley, as Jones is completing passes 1.9 percentage points over expected against man, with a more respectable QBR of 71.5.

Interestingly, Jones’s coverage splits are the inverse of league trends. At nearly every depth of target from zero to 30 yards, quarterbacks’ completion percentages are higher against zone coverage than against man in 2019.

The gap between zone and man is particularly pronounced on throws of 10 air yards or less. This makes intuitive sense: Defenses playing zone are typically happy to allow the short completion and rally for a tackle. But the success of man versus zone on deeper passes is more of a surprise. Zone seeks to take away the deep ball in favor of short, manageable gains. But in 2019, passers are completing a higher percentage of attempts against zone of up to at least 28 yards.

Meanwhile, play-action across the league has been quite successful against man coverage, which might come as a surprise to some NFL coaches.

Man is still the more effective coverage, but the gap between play-action and other passes is wider against man coverage than zone, making it a preferred tactic on intermediate throws.

Yet these leaguewide base rates don’t fit Jones’s statistics. Jones is an enigma — bad at things that most QBs excel at, like completing passes on play-action, yet good at some aspects of the game that many quarterbacks find extremely challenging. Against disguised coverages, for instance — coverages that start out looking like man or zone but then switch mid-play — Jones has the highest completion percentage over expected in the league4 at 10.8 percent. It’s pure zone coverage that’s his kryptonite.

Jones’s struggles against zone coverage likely explain at least some of the Giants’ disappointing year. He’ll need to show progress before next season if New York has any hope of competing with the Dallas Cowboys and Philadelphia Eagles in the NFC East. But there are some signs that he may be improving: Jones’s lone TD against zone coverage came in last week’s Week 12 loss to Chicago. A strong finish to the season might be enough for the Giants to find a reason for optimism heading into 2020.

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How Do You Find Good NFL Defenders? By Measuring What’s Not There.

The New England Patriots’ Stephon Gilmore is widely considered one of the best cornerbacks in the NFL. Through Week 11, he had given up a 47.1 passer rating when targeted this year — to put that into perspective, a 39.6 passer rating is awarded to a quarterback who spikes the ball on every play. (Through Week 11, no qualifying starting QB in 2019 had a passer rating lower than 70.) Because of his prowess, offensive coordinators and QBs don’t even look his way: Of the 326 passing attempts against the Patriots this year, only 64 (19.6 percent) came against Gilmore.

When it comes to measuring this aspect of defensive performance, we’re only beginning to scratch the surface. That’s because individual defense is inherently difficult to assess: A player’s defensive impact may be more significant in the absence of activity, but we can only count things that do happen. To measure a defensive player, we’re always chasing ghosts, trying to count things that don’t.

But thanks to the NFL’s Next Gen Stats tracking data — and the impressive work of researchers such as Baltimore Ravens personnel analyst Sarah Mallepalle2 — we can visualize that absence of activity.

A useful example involves where on the field opponents choose to attack a defense. Every week, coaches huddle around game film, analyzing defensive schemes and players, planning how to exploit what they see. The results of that game-planning show up in the tracking data. Here are charts that show where every team’s pass defense was the most and least vulnerable in the first eight weeks of the season:3

The charts shown are scaled from blue to white and white to red, with red representing the locations where offenses attempted the most passes against the defenses, blue representing the fewest pass attempts and white representing the average number of passes. In theory, the blue areas are places where the absence of activity reveals defensive strength.

In practice, it’s more complicated to solve the problem than simply plotting the distribution of all passing attempts or completions. Some offenses pass in unique ways because of their schemes and the skill sets of their quarterbacks and receivers. Take the Seattle Seahawks, for example:

Seattle QB Russell Wilson’s pass attempts are skewed to the left.4 Why? This is likely because of the inability of D.K. Metcalf, the Seahawks’ rookie wide receiver and 2019 second-round pick, to run a full tree of routes. During the season’s first two weeks, he was targeted only while lining up on the left side of the field. Through the first half of the season, Metcalf had been targeted 45 times, and only 10 were on the right side of the field.

Given that the Seattle passing attack is skewed, we don’t want to penalize any defense’s right side5 just because those defenders had to match up against Metcalf. So to normalize for an opposing offense’s usual tendencies, I compared an offense’s pass distribution against the defense in question with that offense’s distributions against the other defenses it has faced during the 2019 season. We can consider the difference to be the defense’s relative effect on a typical offense’s gameplan.

Let’s take a deeper look at the Buffalo Bills.

The Bills defense has been outstanding, giving up 304.1 total yards and 197.8 passing yards per game through Week 11 — third best in the league in both categories. But we can see a clear disparity in how opposing offenses are attacking starting cornerbacks Tre’Davious White and Levi Wallace. White’s reputation and production seem to have discouraged offenses from throwing in his direction. So far this season, White has given up a 58.9 passer rating on 66 targets, compared with a 101.2 passer rating on 79 targets for Wallace.

The beauty of the Bills’ defense is that their star cornerbacks don’t “shadow” or follow specific opposing WRs wherever they line up. Instead, they mainly stay on one side of the field, no matter who lines up there. Through Week 8, White had lined up on the left side of the field for 97 percent of his snaps, and Wallace lined up on the right side of the field for 96 percent of his snaps.

Our chart reflects that, as well as which cornerback scares off opposing QBs and where on the field that is. Opposing offenses target the left side of the field significantly more against Buffalo (to challenge Wallace, the weaker corner) than when they play against other defenses.

This approach to analyzing defense assumes that teams react rationally to defensive weaknesses they see on tape. That assumption may not always hold true, but taking note of changing tendencies is still one of the best ways to look for those hidden absences of activity that are key to identifying good individual defense.

We still don’t know if these splits have any predictive power. But this is the next logical step in understanding passing: analyzing the horizontal level. At a minimum, these new visualizations provide an interesting new insight into how offenses change in order to attack defenses.

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