The Steelers were the best pass defense in football in 2020, while the Cardinals were in the top 10 and the Broncos just missed. Each of those three teams has brought in plenty of new faces in the defensive backfield, but there’s reason to believe that despite the changes, they’ll be even better in 2021.
We have spent the past couple of weeks breaking down and analyzing offensive slot-wide splits, sorting through wide receivers, quarterbacks, and tight ends and running backs. Now, we can finish up by flipping the script and see how defenses coped with the ever-increasing amount of slot receivers putting up huge numbers.
This charting data once again comes from our friends at Sports Info Solutions. As a reminder, each player’s position is based on where they lined up on the field, rather than relative to other wideouts. The outside receiver in a bunch formation is still considered a slot receiver as opposed to an outside receiver.
2020 Defense: Overall Slot v. Wide
Our first table looks at all targets each defense faced that were thrown to any player in the slot or out wide. We have listed each team’s DVOA and number of passes against both slot and wide targets; the rate of passes to players in the slot as a share of passes to either slot or wide receivers (Slot%); and the difference in DVOA from wide to slot. As a reminder, negative DVOA means better defense.
When reading this table, keep in mind that slot DVOA is significantly more consistent from year to year than wide DVOA. The correlation in slot DVOA from 2019 to 2020 was 0.35, compared to 0.21 for wide DVOA. And that 0.21 for wide DVOA is unusually high; it was at just 0.02 between 2018 and 2019. Teams that are good at defending the slot tend to remain so year after year, while teams good at shutting down receivers out wide tend to revert more towards the mean in future seasons.
There are a number of factors playing into that, though the most significant might be the sheer number of players involved. When a receiver splits out wide, defenses will generally match them up with one of their top two cornerbacks. SIS charting listed 71 different defenders as the primary coverage guy on at least 20 wide targets, or 2.2 per team. But a slot target? That might come from a boundary corner moving inside to follow a top receiver, or a nickel or dime corner against a shifty slot guy, or a safety or linebacker matched up against a tight end or running back. There were 111 different defenders covering at least 20 slot targets in 2020, or 3.5 per team. If 20 feels like too arbitrary a cutoff for you, there were 551 defenders with at least one target in the slot compared to 417 out wide. Interior coverage tends to have more moving parts than boundary coverage, so the effects of one guy having a good or bad season, or one injury or free-agent acquisition altering your starting lineup, tend to be less impactful inside.
So does that bode well for Pittsburgh, Arizona, and Denver, all of whom put up top-10 performances in the slot in 2020 but couldn’t crack the top 20 out wide? If the pull of statistical regression is the most fundamental force in the universe, sure, but the fact that these three teams will have five new starting outside cornerbacks probably has more of an effect than any regression from 2020.
For the Steelers, their struggles out wide were less about the players involved than about first- and second-half splits. Over the first half of the season, they had a 22.3% DVOA against wide targets, third-worst in the league. That improved to a more respectable -8.2% over the last eight weeks, placing them firmly in the middle of the pack and mirroring the improvement of overall pass defense, which went from -14.5% to -25.4% as the year went along. There isn’t an obvious explanation for this, no mid-season returns or sudden shifts in the schedule or anything; they simply gave up some big games to Darius Slayton, A.J. Brown, and the other wideouts they faced early in the year. More important than the splits, however, is the personnel. The Steelers’ top-targeted outside corner was Steven Nelson, and he’s gone, off to Philadelphia in a cap space move. Nelson ranked eighth in coverage success rate a year ago and allowed a perfectly adequate 6.6 yards per target; while he’s not an irreplaceable piece, he does leave at least some moderately sized shoes for Cam Sutton to fill. And if Sutton does spend more time outside, that brings up questions for slot performance, as the two Steelers who spent the most time covering in the slot were Sutton and the departed Mike Hilton. We still have Pittsburgh projected with the top defense in 2021, but I think it’s safe to say that there are questions in the secondary at the very least.
While the Steelers were shedding corners, the other two teams up there were adding them. Denver was on this list last year as well—strong in the slot, poor out wide—and we suggested that replacing Chris Harris with A.J. Bouye might bring success. Well, a shoulder injury, a concussion, and a suspension ended hopes there, and the duo of Michael Ojemudia and De’Vante Bausby ended up being less than an ideal pair of boundary corners in a division where you have to face Patrick Mahomes and Justin Herbert twice a year each. Phrased like that, drafting Patrick Surtain in the first round makes a ton of sense, as does bringing Kyle Fuller and Ronald Darby in in free agency.
Arizona, too, will have a new top pair of boundary corners, as Dre Kirkpatrick and Patrick Peterson were their top two defenders last season, and both struggled mightily. The Cardinals going old, with Malcolm Butler coming in in free agency and Robert Alford returning after missing two years with injury. That’s … less than ideal, but it’s hard to imagine them being much worse than the Kirkpatrick/Peterson duo was a year ago.
Butler leaves Tennessee, which had reverse splits from the teams we just talked about—near the top out wide, and near the bottom defending the slot. Butler ended up being the top-targeted Titans defender in both, so Tennessee’s pass coverage will look different all over the field. In fact, the Titans will have to replace both of their most frequent slot defenders, with Desmond King off to Houston; it was something of a purge of a bland secondary this offseason. With the top three corners in snap count gone, it’s safe to say that Tennessee’s secondary is in flux. That’s not the case in Los Angeles, where Jalen Ramsey and Darious Williams return after leading the Rams to the top DVOA both out wide and deep; if you wanted to have success passing against the Rams, you were limited to a box in the interior of the field. The Rams’ top two defenders in the slot were Troy Hill and John Johnson; both are in Cleveland now as the Rams lost a lot of pieces from last year. They’ll need young players such as Terrell Burgess and David Long to step up if they’re going to maintain anything like last year’s success.
And then there are the Houston Texans. They were a sieve out wide, ranking 24th with an 8.1% DVOA. And then they were a leaky sieve in the slot at 33.1%. And yet, the Texans are trotting out mostly the same secondary they had last season—Vernon Hargreaves, Eric Murray, Bradley Roby, Keion Crossen, and Lonnie Johnson are all back, with Philip Gaines being the only Texans defensive back with 20 slot/wide targets to not return in 2021. I think it’s safe to say that the secondary wasn’t the primary issue the Texans had last season, but it is odd, in this Houston era of “competition” as both philosophy and buzzword, to see so little change here.
2020 Defense vs. Wide Receivers
The next table features the same data as the previous table, but limited just to targets that went to wide receivers.
As expected, this is very similar to the previous table. Wide receivers get the majority of pass targets, and that’s doubly true out wide. 77% of slot targets and 91% of wide targets went to wide receivers, so for most teams, differences here were slight at best.
Not for the Panthers, however! Carolina rises from 21st to 14th in slot DVOA when you only look at wide receivers; they failed to match up properly against running backs and tight ends working out of the slot. An 11% rise in DVOA in this split is nuts—and most of it comes from removing the efforts of Shaq Thompson from the equation. As we’ll see in upcoming tables, Carolina ranked in the bottom six against both running backs and tight ends in the slot, and Thompson was the primary victim—he was charted as the primary defender on 11 of the 55 targets, allowing a success rate of 73%, and I suspect a healthy portion of the nine targets without a primary defender listed were Thompson’s responsibility as well. Take him out, and the Panthers look … “good” would be an overstatement, but more competent. In a division where you have to face each of Jared Cook, Rob Gronkowski, and Alvin Kamara twice a year, not to mention Kyle Pitts joining Arthur Smith in Atlanta, this seems like the kind of problem Carolina needs to solve.
The Rams had the opposite problem, falling from 13th to 21st if you only look at their performance against receivers in the slot. They got destroyed by the combination of Gabriel Davis and Cole Beasley against Buffalo (combined nine targets in the slot for 172 yards), and Deebo Samuel caught 12 of 13 targets for 159 yards in his two appearances against Los Angeles. Take out those opponents, and the Rams rise to a much more respectable -9.1% DVOA, which would have ranked seventh. Of course, chalking Buffalo up to one bad game is all well and good, as the Bills are in the opposite conference. Waving away two games a year against the 49ers is a slightly harder argument to make. As mentioned, the Rams have an entirely new interior coverage unit coming into play this year; they’ll have a tall task in a division that can trot out Tyler Lockett, DK Metcalf, Brandon Aiyuk, and DeAndre Hopkins, all of whom had over 100 DYAR in the slot last season.
And then you have the Vikings, who went from eighth to 20th in wide DVOA, even though we’re only taking 12 passes out of the equation! Against non-wideouts split wide, Minnesota managed two interceptions (both inside their own 25-yard line), four incompletions, one completion for negative yardage, four failed completions for positive yardage, and a touchdown in garbage time against Detroit. That’s a DVOA of -177.8%, and even over only 12 attempts, that adds up.
2020 Defense Versus Running Backs
These last two tables are here mostly for completeness. The average defense faced 8.3 pass attempts all season against running backs in the slot and just 7.8 split out wide. Nearly 20% of all running back slot/wide targets went to J.D. McKissic, Nyheim Hines, or Chase Edmonds. We have ranked defenses by DVOA here for you, but this is small sample size theatre at its finest.
Small sample sizes produce disproportionate results, but Detroit putting up a 65.7% slot DVOA on 13 targets—or more than twice as many as anyone who ranked below them—is frighteningly impressive in its way. It’s even more impressive when you realize that six of those 13 targets went to McKissic, who had a below-average DVOA against the Lions. Take McKissic’s struggles out and Detroit’s DVOA climbs to 120.8% as Alvin Kamara, Ameer Abdullah, Aaron Jones, and Chase Edmonds took turns embarrassing the Lions; every running back not named McKissic who received a slot target against the Lions caught the ball.
2020 Defense Versus Tight Ends
Tight ends split out wide are essentially not a thing; the clue is in the name. Only five tight ends—Darren Waller, Gerald Everett, Eric Ebron, Jimmy Graham, and Travis Kelce—hit double-digit targets split out wide in 2020. The slot column is a little more meaningful; it’s still small sample sizes, but every defense had at least 30 targets to go on.
Hello, Green Bay! A -60.7% DVOA against tight ends in the slot is the best we have seen since we started collecting this data. Seven different tight ends had at least four targets in the slot against the Packers, and six ended up with negative DYAR—Jonnu Smith, Cole Kmet, Trey Burton, Tyler Eifert, Dallas Goedert, and T.J. Hockenson. Oddly, the only tight end to have any degree of success against the Pack was Zach Ertz, the worst tight end in football last season by DYAR—he picked up two first downs on Philadelphia’s only two scoring drives against the Packers in December. Hey, in a small enough sample size, anyone can have a good day, even the worst tight end in the league against the top tight end defense in football.