Five weeks into the NFL season, we still have a small sample, but it's enough to look at some early trends. Some things in the NFL are just as we expected, but other metrics have given us surprising results so far in 2020.
Below, we'll look at a surprising stat for each of the AFC teams, using a mix of numbers from Football Outsiders and ESPN Stats & Information, as well as what that stat might tell us about that team going forward. (Click here for last week's examination of the 16 NFC teams.)
Baltimore Ravens: Lamar Jackson running
Lamar Jackson is running less than he did in his MVP season, and more importantly, he's running with less success.
In 2019, Football Outsiders calculated Jackson to have 273 rushing DYAR (defense-adjusted yards above replacement, explained here). That was the second-most valuable quarterback rushing season in our data, going back to 1985, surpassed only by Randall Cunningham's 1990 season. This year, on the other hand, Jackson has negative DYAR. He currently ranks 29th among quarterbacks in rushing value.
Jackson has run only 7.4 times per game, compared to 10.4 carries per game last season. That's exacerbated by a recent knee injury that held Jackson out of some practices and limited him to two carries against Cincinnati in Week 5. But the injury isn't the reason for the lack of success in Weeks 1-4, and Jackson's success rate has dropped on every down:
Will this drop in Jackson's rushing efficiency continue? In part, it depends on the status of his knee, obviously. In addition, it's hard to have a performance as good as Jackson had last year while rushing as often as he did. The most likely scenario for the rest of 2020 is a performance that falls somewhere between Jackson's slow rushing start and last year's huge numbers.
Buffalo Bills: Everything
Want a surprising stat about the 2020 Buffalo Bills? Try "all of them."
You probably already know about the sudden development of quarterback Josh Allen, who is currently third in QBR after ranking 24th in each of his first two seasons. What you might not realize is that Allen and the passing game have carried the team to its early 4-1 record because everything else is struggling.
Buffalo's running game, which was close to league average a year ago, currently ranks dead last in the NFL in DVOA. Most of the problems here seem to be related to the offensive line, which currently ranks just 25th in adjusted line yards and 28th in run block win rate.
A bigger shock than the struggle of the running game is the poor play of the defense. The Bills' defense ranked seventh and second in DVOA the past two seasons, and they went into the year as Football Outsiders' No. 1 projected defense for 2020. They haven't been anything close to that, ranking 27th in defensive DVOA. The Bills are having problems against both the run and the pass.
Here the problems seem to have more to do with the back seven than the defensive front. The Bills rank third in pass rush win rate, and they are average in run stop win rate. However, the Bills rank 30th in DVOA against passes in the middle of the field. They rank 25th against deep passes (16 or more air yards) after ranking second last year, and they have dropped from second to 28th in DVOA covering opponents' No. 1 receivers.
It's likely that reversion to prior performance is going to bring these numbers closer to what we've seen in the past. Allen will probably slow down a bit, but the running game will find more success. The defense should be better going forward, but there's a worry that because of injuries, that could be long-term. Linebacker Tremaine Edmunds is playing at less than 100 percent because of a shoulder injury. Linebacker Matt Milano is dealing with hamstring issues, and top corner Tre'Davious White has back problems. These could all be lingering injuries that plague the defense all year.
Cincinnati Bengals: The decline of A.J. Green
The biggest surprise with the Bengals this year has been the decline in Green's production. We expected the 32-year-old receiver to come back and revitalize the Bengals' offense after missing all of 2019. Instead, Green has caught just 14 of 34 targets for a measly 119 yards with no touchdowns. He currently ranks dead last in value, according to Football Outsiders' DYAR metric.
Green looks noticeably slower this year, but how much does that matter to his game? According to NFL Next Gen Stats, he's near the bottom of the league, with just 1.65 average yards of separation, but that's no different from past years. Green's game is more about contested catches than beating corners with speed or elusiveness. He had an average separation of 1.98 yards in 2018, similar to that of other contested-catch receivers such as Allen Robinson II and Mike Evans.
A bigger problem seems to be Joe Burrow's just missing Green. More than half of the passes to Green have been charted by ESPN Stats & Info as overthrown or underthrown.
Some of these stats would point to Green having a bit of a rebound in the next few weeks, except that there are questions about his place in the Cincinnati passing game. He had to leave Sunday's game against Baltimore early because of a hamstring injury, and he's rumored to be on the block with the trade deadline approaching.
Cleveland Browns: Offensive line
The Browns' offensive line was a major problem last year, and this year, it's a major strength, especially in the running game. The Browns have gotten a great performance out of right guard Wyatt Teller, and they made excellent additions in rookie left tackle Jedrick Wills Jr. and free-agent right tackle Jack Conklin. But perhaps the best addition was offensive line coach Bill Callahan, who has coached some of the NFL's best lines over the past two decades.
The Browns lead the league in Football Outsiders' adjusted line yards stat, which measures runs at specific distances to get a better idea of how productive blocking is compared to a back on his own. The Browns are also fourth in run block win rate after ranking a dismal 31st in that metric last year. They are third in pass block win rate, though you might be surprised to learn that they already ranked sixth in that metric in 2019.
Denver Broncos: Offensive line
Denver's surprising stat is the opposite of Cleveland's surprising stat: The Broncos' offensive line is really struggling this year. Denver ranks 31st in adjusted line yards and dead last in run block win rate. The Broncos are also dead last in pass block win rate -- and by a good margin: The gap between Denver and No. 31 Miami equals the gap between Miami and No. 22 Minnesota.
The run block win rate is particularly weak in the interior, with guards ranking 29th and center 32nd. Center might not be a surprise because starter Lloyd Cushenberry III is a rookie. But guard is a significant surprise. Left guard Dalton Risner had an excellent rookie season, and right guard Graham Glasgow was a key free-agent addition.
Houston Texans: Overall DVOA
According to Football Outsiders metrics, the 1-4 Texans have been an above-average team over the course of this season. They are fourth in the league with 6.4 yards per play on offense. Their success rate is less impressive but still around average, ranking 14th in the league. On defense, Houston is also slightly above average, with 5.6 yards allowed per play, and the team ranks 18th in success rate. DVOA takes this surprisingly good performance and further adjusts it for Houston's schedule, which has been the second toughest in the NFL so far this season, behind only Minnesota's. Put it together, and DVOA ranks Houston 12th overall. All four of the Texans' losses have come against teams ranked higher than them in our metrics.
As I write about here, this makes Houston one of the best 1-4 teams we've ever tracked (going back to 1985). The bad news for the Texans is that none of the other similar teams was able to turn things around and make the playoffs after its "unlucky" start. Houston is probably an average team rather than a bad one, but the Texans are probably limited to playing spoiler for the rest of the season.
Indianapolis Colts: Philip Rivers when losing
Is Philip Rivers toast at this point? He certainly looked it at times against Cleveland in Week 5. But overall this season, Rivers hasn't been terrible. He has been very average, with 0.2% passing DVOA. (League average is exactly zero.) It's clear when Rivers has been terrible this year, though: when trailing.
What's surprising here might not be that an older quarterback struggles when trying to come back from a deficit. Instead, what's surprising is that Rivers did not struggle like this last season. In 2019, Rivers had a slightly above average 7.7% passing DVOA when losing and an even better 24.4% passing DVOA when losing by more than a touchdown. That was despite the fact that Rivers threw 15 of his 20 interceptions last year when trailing. (Leaguewide, roughly 60% of interceptions are thrown when the offense is trailing in the game.)
Jacksonville Jaguars: Red zone defense
Overall, the Jaguars have been the worst defense in the league this year, according to both yards per play and DVOA. But the Jaguars have been surprisingly strong inside the 20, ranking 10th in DVOA in the red zone. Opponents have managed touchdowns on only 12 of 21 red zone appearances, which ranks ninth in the league.
The bad news for Jacksonville is that over time, red zone defensive performance tends to revert to match defense overall. As such, it is very likely that the Jaguars, already stuck at 1-4, are going to be allowing even more touchdowns the rest of the season.
Kansas City Chiefs: Patrick Mahomes vs. the blitz
Nobody has yet found a way to shut down Patrick Mahomes, but teams might be finding a way to reduce him to merely "very good" instead of superhuman.
The trick is apparently to send only three or four pass-rushers and drop the rest of your defense into coverage instead of blitzing. Both Las Vegas and New England used this strategy in the past couple of weeks to frustrate the Kansas City offense.
The difference has been pretty big so far this season. Against three or four pass-rushers, Mahomes has an 81.8 QBR with a 61.8% completion rate and 6.4 yards per dropback. Against a blitz of five or more pass-rushers, Mahomes has a 99.4 QBR with a 70.7% completion rate and 10.4 yards per dropback.
The same split existed in Mahomes' first two seasons as a starter, though not to same extent. In 2018 and 2019, Mahomes had an 80.1 QBR against three or four pass-rushers and a 90.0 QBR against five or six pass-rushers, though his completion rate and yards per dropback were similar against both a standard pass rush and a blitz.
Las Vegas Raiders: Average depth of target
Derek Carr is renowned for building his game around the short pass, but that has changed somewhat this season. He isn't quite Russell Wilson yet on the deep ball, but he's throwing deep a lot more often than in previous years.
Carr's average depth of target so far this season has been 7.1 yards, which ranks 22nd out of 29 quarterbacks with at least 100 passes. He has also had some long defensive pass interference gains; if we include DPIs, Carr's average depth of target improves to 7.8 yards, which ranks 19th.
Compare this to last season, when Carr had an average depth of target of 6.5 yards, or 6.6 yards with DPIs included. Both figures ranked him 32nd out of 34 quarterbacks with at least 200 passes.
We're also seeing this change in Carr's game specifically on third downs. Football Outsiders uses a stat called ALEX (Air Less Expected) to measure each quarterback's average throw on third downs compared to what he needs to convert. Two years ago, Carr's ALEX was a dismal 0.3, near the bottom of the league. Last year, it was 1.3, closer to average. This year, Carr's ALEX of 3.3 yards ranks him fifth in the NFL.
Obviously, rookie speedster Henry Ruggs III is a big part of the change, and he has been the intended receiver on six of Carr's 15 passes of 25 or more air yards. But Carr has also thrown bombs to Hunter Renfrow (5), newcomer Nelson Agholor (3) and even fullback Alec Ingold (1).
Los Angeles Chargers: Second-half defense
The Chargers have lost four games by a touchdown or less this season. In three of those games, the Chargers blew a halftime lead of more than a touchdown. The main reason the Chargers blew those leads is that their defense seems to disappear at halftime every week.
Before halftime this year, the Chargers have the best defensive DVOA in the league, 23.1% more efficient than average. After halftime, the Chargers rank 28th in DVOA, 20.1% worse than average.
There's a similar drop in efficiency on offense, but it is much smaller: The Chargers go from 13th in offensive DVOA before halftime to 22nd after halftime.
The good news for the Chargers is that there's no evidence that this kind of first-half/second-half split is "real," i.e. that this is predictive of similar splits in the future. Last year, for example, teams that had a significant split in the first five weeks of the season often had the exact opposite split the rest of the year. New Orleans, for example, had numbers in Weeks 1-5 of 2019 similar to what the Chargers have this year. But from Week 6 on, the Saints' defense was better in the second half of games than it was in the first half.
Miami Dolphins: Third-down defense
Last year, Miami had the worst defense in the league, according to our DVOA ratings. In fact, the Dolphins had one of the worst defenses we've measured in the past 35 years.
This year, the Dolphins have been a little better. This week, they climb to 27th in defensive DVOA. How they get to that rank is really interesting.
Somehow, the Dolphins have put up the best third- and fourth-down defense in the league this season. Opponents have converted 19 of 50 third downs (38%, seventh) and one of seven fourth downs (14%, first). DVOA likes the Dolphins even more than those raw numbers, thanks to four third-down turnovers that have prevented the opponent from gaining field position with a fourth-down punt.
At the same time, the Dolphins have put up the worst first-down defense in the league. The third-down defense doesn't help as much as you think because opponents are moving the sticks without getting to third downs. A league-leading 32% of first-down plays against the Dolphins have converted for a new series of downs, and they allow a league-worst 8.1 yards per play on first downs.
As you might imagine, this split between first and third downs is completely unsustainable. First downs represent a much bigger sample than third downs, and overall it's likely that the Miami defense is going to decline in the future as the third-down performance comes down closer to the first-down performance.
New England Patriots: Poor defensive coverage
We know that defense is less consistent than offense from year to year, but you might be surprised to learn how far the Patriots' defense has fallen this year. This is especially true if you saw them play against Kansas City on national television last Monday. It looked like the Patriots were shutting down the Chiefs' passing game because the Chiefs scored only 26 points, but the Patriots had an average defensive performance, according to our DVOA ratings, even after adjusting for the quality of the Kansas City offense. After four games, the Patriots rank 23rd in defensive DVOA, including 21st against the pass.
The Patriots are renowned for the quality of their man coverage, so those numbers should shock you. The Patriots have used man coverage on 63% of passes this season, fourth in the NFL. They've allowed 6.8 net yards per pass, which ranks 23rd in the league, and a 62.7% completion rate, which is tied for 16th. Compare this to last year, when the Patriots allowed just 4.6 net yards per pass with man coverage (second) and a 51.2% completion rate (first).
New England's numbers when using zone coverage might be even more shocking, though. They're really, really bad so far this year. Through four games, the Patriots are allowing a league-worst 8.4 net yards per pass when using zone coverage, and their 84.1% completion rate allowed is ranked 31st. (Last year, these numbers were 5.8 net yards and 68.7%, respectively.)
New York Jets: Run defense
This season, a surprising stat about the New York Jets would be anything the New York Jets do well. But there is something the Jets are really good at: run defense. In fact, the Jets have been excellent at defending the run for a couple of years now.
You might be extra surprised that the Jets are good at defending the run because you remember a couple of big highlight plays against them, such as the 80-yard touchdown Raheem Mostert had in Week 2. But the Jets are really good at stopping runs up front before they get going. The Jets rank ninth in run defense DVOA because of a couple of those long highlight runs. But up front, the Jets are third in adjusted line yards allowed and seventh in run stop win rate. They lead the league in run stop win rate from the interior part of the defensive line.
This is all a continuation of last season, when the Jets were No. 1 in run stop win rate, second in run defense DVOA and third in adjusted line yards allowed. Unfortunately, this kind of consistently strong run defense would be more impressive if we were living in 1975, when the running game was a lot more important to winning and losing.
Pittsburgh Steelers: Run defense
Like the Jets, the surprising stats for the Steelers show just how strong they've been against the run so far this year. Pittsburgh leads the league with the lowest adjusted line yards allowed and best run defense DVOA, as well as a 35.7% run stop win rate. The Steelers have stuffed a league-leading 33% of running back carries for a loss or no gain.
Why is this different from the Jets? Unlike the Jets, the Steelers weren't as good against the run in 2019. Last season, they were 11th in adjusted line yards allowed and 17th in run stop win rate. But also, unlike the Jets, the Steelers' defensive front is not one-dimensional. Pittsburgh leads the league in adjusted sack rate and ranks second behind Tampa Bay in pass rush win rate.
Tennessee Titans: Third-down defense
Our surprising stat for the Titans probably isn't so surprising if you watched Tuesday's game against the Bills. Tennessee's gigantic win somewhat hid the fact that the Titans absolutely could not get off the field on third down, allowing the Bills to convert 13 of 17 opportunities. That has been a problem for the Titans all season, and Tennessee ranks 30th in DVOA on third and fourth downs. By comparison, Tennessee ranks ninth on first downs and seventh on second downs.
The good news here for the Titans matches the bad news for the Dolphins: third-down performance on defense tends to regress toward a team's total performance over time. As such, it's likely that the Titans will do a better job getting off the field on third downs going forward. That will help in games in which they don't get two interceptions from Malcolm Butler to go with four touchdowns from Ryan Tannehill.