We still have a small sample size four games into the NFL season, but it's enough action 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 NFC 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. Next week, we'll do the same for the AFC.


Arizona Cardinals: overall offense
The most surprising stat so far for the Cardinals is how stagnant their offense has been despite the addition of wide receiver DeAndre Hopkins. Last year, Arizona finished the year 13th in our offensive DVOA ratings. They were eighth in our weighted rating that gives more strength to games at the end of the season. With quarterback Kyler Murray ready for a second-year jump in efficiency, all indications were that the Cardinals would have a top-10 offense.
Instead, the Cardinals are just 25th in offensive DVOA so far this year. The biggest problem comes on third downs, where the Cardinals are dead last in DVOA. Last year, the Cardinals were 17th in DVOA on third downs.
One problem might be that Kliff Kingsbury's modern, cutting-edge offense is eschewing one of the hallmarks of the best modern, cutting-edge offenses. The Cardinals rank 31st in use of motion at 27.5%, according to ESPN Stats & Information charting. Only the Jets are lower.
Everything we knew going into the season suggests that the Cardinals' offense should improve going forward, and it will have to improve if they are going to be playoff contenders in the tough NFC West.

Atlanta Falcons: short-yardage offense
The Falcons rank 31st in DVOA in third-and-short/fourth-and-short situations, with 1 to 2 yards to go. Atlanta has converted on 6 of 13 such opportunities (46%). Leaguewide, teams are converting 69% of these situations so far.
This one is likely to regress toward the mean, especially when you look at some of the reasons the Falcons have not converted in short yardage. They failed to convert two different Wildcat formations with Russell Gage at quarterback (one was a deep throw to Julio Jones), and they blew a fourth-and-2 when safety Sharrod Neasman gained two yards on a fake punt but then fumbled the ball away to Seattle.

Carolina Panthers: pass rush
Carolina has only three sacks, fewest in the NFL. The Panthers rank 31st in adjusted sack rate, which measures sacks and intentional groundings per pass play, adjusted for situation and opponent. This is a bit surprising because the Panthers were third in the league in adjusted sack rate last year. Yes, there was a lot of defensive turnover in Carolina, but top pass-rusher Brian Burns is one of the holdovers.
Will the Panthers continue with this year's lack of sacks? Other metrics tell very different tales. The Panthers are 28th in pressure rate, which tends to predict future sacks better than past sack totals. That's still pretty bad. On the other hand, Carolina is currently fifth in pass rush win rate, which could be a sign that the pass pressure is going to improve for the Panthers going forward.

Chicago Bears: first-down defense
Chicago's defense ranks seventh in DVOA this year, in line with last year's rank (eighth). But the splits that get the Bears to that rank are interesting. Chicago is just 27th in defensive DVOA on first downs. Then that improves to fourth on second down and sixth on third down.
The biggest issue isn't that opposing offenses get into good down-and-distance situations on second down. It's that they skip over second down entirely, as 31% of first-down plays against Chicago earn another set of downs, compared to an NFL average of 23%.
Will this continue further into the year? Probably not to this extent, but it was a problem for the Bears in 2019, as well. Last year, the Bears' defense ranked 16th on first downs, then eighth on second downs and fourth on third downs.

Dallas Cowboys: pass coverage
So far, the Cowboys rank 25th in defensive DVOA against No. 1 receivers and 27th in DVOA against No. 2 receivers. After Sunday's loss to Cleveland, a lot of attention has been paid to the Cowboys' poor run defense. But based on our numbers, the Dallas pass defense (25th in DVOA) has actually been worse than the run defense (23rd). The Cowboys have allowed four 100-yard receiving games so far, to Robert Woods of the Rams, Calvin Ridley of the Falcons and both Tyler Lockett and DK Metcalf of the Seahawks.
Dallas lost star cornerback Byron Jones in the offseason, and two of their three starters from Week 1 are currently injured, Anthony Brown and Chidobe Awuzie. The third starter is a rookie, Trevon Diggs. The good news is that Brown is likely to return from his rib injury soon. Awuzie will be out at least two more weeks, possibly longer, with a hamstring injury.

Detroit Lions: fumbles
The Lions have fumbled the ball exactly zero times so far this year. Zero fumbles! Surely this is the sign of a well-disciplined team.
This Lions are not likely to go without fumbles for the rest of the season.

Green Bay Packers: red zone offense
The Packers have the best offense in the league this season, but believe it or not, there's one place their offense hasn't been as efficient: the red zone. Green Bay ranks just 23rd in red zone DVOA despite leading the NFL in offensive DVOA overall. The Packers are a little better in conventional metrics, as 13 touchdowns out of 20 red zone appearances ranks 13th in the league, but that still doesn't match what the Packers have done with the rest of their offensive plays. Running has been a problem: half of the Packers' runs inside the 10 have gone for a loss or no gain.
The good news for the Packers is that red zone performance tends to regress to match the rest of a team's performance. Considering how good the Packers are on offense otherwise, it's very likely their performance in the red zone will improve in the future.

Los Angeles Rams: special teams
The Rams have the No. 31 special-teams unit in the NFL so far this season. It's surprising because you probably thought of the Rams as having one of the better special-teams groups in the league, in part because of punter Johnny Hekker. But the Rams' overall special teams and Hekker's value on punts have both dropped every year since 2016, when Hekker had the best year for any punter in our 35-year database. Right now, the Rams have negative punt value as compared to average, which they haven't had for a full season since Hekker's rookie year of 2012. Place-kicking also has been an issue, with a blocked extra point against Philadelphia and two missed field goals (out of seven) -- including a 29-yarder -- against Dallas in Week 1.
The good news for the Rams is that special teams is less consistent than offense or defense, so there's a good chance they can reverse the poor special-teams play and be at least average for the rest of the season.

Minnesota Vikings: red zone defense
According to our metrics, the Vikings have been the No. 1 defense in the red zone so far this season, with a -43.8% DVOA. Minnesota has allowed opponents to score a touchdown on just 41% of red zone trips (7-of-17), second in the league behind Chicago.
This sounds like a positive development, but it actually should be a bit worrying to Vikings fans. As noted in the Green Bay section above: over time, red zone performance tends to regress toward a team's overall performance. And Minnesota's overall defense is close to league average (13th in DVOA). So it's likely the Vikings will be giving up more touchdowns instead of field goals going forward.

New Orleans Saints: penalties
The Saints lead the NFL with 398 penalty yards so far this season. That includes a whopping 244 yards on 11 defensive pass interference calls. No other team has more than 100 yards on defensive pass interference so far this year! The Saints only were called for defensive pass interference 12 times in the entire 2019 season.
The good news for the Saints is that there is essentially no correlation between penalty yardage at the start of the season and penalty yardage for the rest of the season. Over the past five years, the correlation coefficient between these two stats was a measly 0.02. The 10 teams with the most penalty yardage in the first four games over the past five years averaged 92 penalty yards per game through Week 4, then just 57 penalty yards per game afterward.

New York Giants: run defense
Linebacker Blake Martinez has made 26 run plays so far (tackles or assists), which ranks fifth in the league. That's not the surprise, because he led the league last year when he was in Green Bay. The surprise is that he is averaging just 2.4 yards gained on his run plays, extremely good for an inside linebacker and significantly lower than last year's average of 4.4 yards. Martinez's strong play so far is one reason the Giants are a surprising 11th in defensive DVOA this season. This would be more exciting if their offense wasn't dead last in the league.

Philadelphia Eagles: overall offense
Obviously, the most surprising stat for the Eagles is the extremely poor performance of the offense. Even after Sunday's upset win over San Francisco, the Eagles rank 31st in offensive DVOA, including being last in passing DVOA. It's a huge change from expectations and from recent years. Last season, the Eagles were 14th in overall offensive DVOA and 17th passing. The year before, they were 16th overall and 13th passing. And back in 2017, when the the Eagles won the Super Bowl, they were seventh overall and fourth passing (in the regular season).
How rare is this kind of drop in offensive DVOA at the beginning of the season? I went back and found 10 teams since 2001 that had a similar drop in the first four weeks of the campaign. I limited my list to teams that started off with the same quarterback as the year before. For the most part, these teams rebounded significantly after their slow starts, from an average of -35.7% offensive DVOA in the first four weeks to -2.8% DVOA the rest of the year. That's at least only slightly below average. The bad news is that these 10 teams averaged 6.4 wins. Even in this year's stumbling NFC East, 6-10 is probably not going to win a division title.

Seattle Seahawks: pass/run ratio
The most surprising thing about the Seahawks is just how much they're "letting Russ cook." Seattle's pass/run ratio has gone way up from recent years. Looking just at the first half of games -- to filter out the effect of running out the clock with a lead -- the Seahawks have dropped back to pass (including scrambles) on a league-leading 69% of plays this season. Compare that to last year at 59% (30th) or the year before at 50% (32nd).
There's no reason to believe this can't continue and no reason that it shouldn't continue, given how well Russell Wilson is playing. He is fourth in both QBR and passing DVOA so far this season.

San Francisco 49ers: run blocking
The 49ers are having problems with run blocking this year. Their overall running game has still been good because of long runs such as the 80-yarder Raheem Mostert had against the Jets back in Week 2. The 49ers rank second in "open-field yards," which is the number of yards they get per carry that come more than 10 yards past the line of scrimmage.
However, the 49ers are only 31st in Football Outsiders' adjusted line yards metric, which cuts runs at specific distances to get a better idea of how well the offensive line is opening holes. The 49ers also rank just 30th in ESPN's run block win rate. This poor blocking performance is a surprise because the 49ers have ranked in the top 10 of adjusted line yards for three straight years, and they ranked 16th a year ago in run block win rate.
My guess is that these stats for the 49ers' offensive line are going to reverse and end up closer to where they were in 2019. The 49ers returned three starters on their offensive line, and they might have upgraded at left tackle by trading for Trent Williams. It's difficult to imagine that right guard Daniel Brunskill is such a step down from last year's starter Mike Person that the entire offensive line has collapsed!

Tampa Bay Buccaneers: passing under pressure
Tom Brady is currently next to last in the league with 2.5 QBR under pressure. Only Dwayne Haskins (1.5) has been worse so far this year.
The good news about it is that quarterback performance from a clean pocket is much more consistent than quarterback performance under pressure. Brady's struggle when under pressure this year does not indicate he'll be that bad under pressure for the rest of the year. The bad news is that Brady's QBR from a clean pocket is also surprisingly low, due to turnovers. A QBR of 75.7 from a clean pocket ranks Brady 17th among the NFL's 33 qualified quarterbacks.

Washington Football Team: pass rush
Washington is No. 1 in adjusted sack rate after four games at 11.0%. On one hand, it's not surprising because Washington was fourth in adjusted sack rate a year ago and added Chase Young to the defensive line this season. On the other hand, this rank is surprising because it doesn't necessarily match Washington's other pass-rush statistics.
Washington is currently just 23rd in pass rush win rate at 37%, after ranking 25th last year, also at 37%. Washington is better in pressure rate, ranking eighth, but that's still not as impressive as Washington's sack rate. This is important because pass rush win rate and pressure rate are "stickier" metrics, more predictive than just sack rate. So it's likely the Washington pass rush is not quite as impressive as its sack rate would suggest early on.