NFC Wild Card Preview
by Aaron Schatz
A friend of mine asked me a couple days ago which team I thought was going to win the Super Bowl this year, and it was in the midst of a long and winding answer that I realized just how much superior the NFC looks compared to the AFC going into this year's playoffs. It's not just that the NFC has five of the top seven teams in weighted DVOA right now. Over in the AFC, all four of the division champions are dealing with major injuries. The top two teams each just lost one of their three or four best players just in the last month. On the other hand, the NFC teams all generally look healthy, including the lower-seeded teams. The Seahawks' offensive line is finally healthy. The 49ers now have Michael Crabtree back. The Packers just got back Aaron Rodgers and Randall Cobb. The Eagles don't have a lot of injuries, and neither do the Saints. The Panthers have to deal with Steve Smith's sprained PCL, but he should be back to play in next week's Divisional round.
Healthier players on the field doesn't necessarily lead to more exciting football -- it will be exciting every time Keenan Allen catches a big pass on Dre Kirkpatrick because Terence Newman is on the sidelines -- but it is just one reason why the NFC is the better conference and whichever team comes out of this conference is probably the favorite in Super Bowl XLVIII.
(Oh, and my favorite for the Super Bowl is the same team I picked to win before the season started: Seattle.)
For those who may be unfamiliar with the Football Outsiders stats, they are explained at the bottom of the page. Scroll down or click this link. Any game charting data that appears with an asterisk appears courtesy of the ESPN Stats & Information Group and is complete through the end of the season. Other game charting data (such as defensive back coverage stats) is roughly 80 percent complete. Please remember that all stats represent regular season only.
New Orleans at Philadelphia
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Everybody knows about the Saints' ridiculous home-road splits this season. Scroll down a bit and look at the New Orleans week-to-week DVOA graph and you will see that I've colored the Saints' home games gold but their road games white, and it's pretty evident what the difference is. Except for a close Week 1 win over Atlanta, every Saints' home game had a higher single-game DVOA than every Saints road game. Overall, the Saints had the league's highest offensive DVOA at home and ranked seventh in defensive DVOA. On the road, they ranked 16th on offense and 21st on defense.
This is where I was planning to go into a long discussion of whether the Saints' struggles on the road were really a long-term issue or just a one-year fluke. However, our old pal Bill Barnwell completely beat me to the punch in his preview of this game, published on Grantland on Thursday. He even used DVOA ranks and everything. Let this be a lesson to me that I really need to work to get these Football Outsiders playoff previews done earlier.
Bill looked at the Saints' rank in offense and defense DVOA each year since they won the Super Bowl in 2009, skipping 2012 because the whole team was sort of a mess after the Bountygate suspensions. Let's expand that a little bit, looking all the way back to the first year Sean Payton and Drew Brees were together in 2006.
New Orleans Saints DVOA, Home vs. Road, 2006-2011 and 2013
Bill pointed out in his Grantland preview that the Saints were actually much better on the road than they were at home in 2010, with the same offensive philosophy (although a different defensive philosophy) and many of the same players. In our expanded table, you can see that the Saints were also much better on the road than they were at home back in 2006, the first time they went to the postseason with Payton and Brees. The size of the Saints' home-field advantage wavers back and forth every year, like it does for pretty much every team.
Our research has long shown that the average NFL team is going to have an offensive DVOA about 8.5% better in home games than in road games, with the same gap for defensive DVOA. This is where our standard answer of "home-field advantage is worth about 17.0% DVOA" comes from. Looking at the home-road splits for the past few years to do this table, there was some indication that home-field advantage has been a little bit smaller in recent years, so the gap for an average team has been more like 7.5% DVOA. Either way, if we look at the combined numbers for the Saints during the entire Payton-Brees period, we get a team that has a slightly higher than usual home-field advantage on offense and a slightly lower than usual home-field advantage on defense. Put the two together, and the Saints end up with pretty much the same home-field advantage as everyone else.
Despite teams like the Giants going on surprising Super Bowl runs in recent years, it's still better to play at home than on the road in the NFL, including in the playoffs. The Saints will have to deal with the usual disadvantage of being on the road. They'll have to deal with an extra bit of disadvantage because historically, teams that play indoors or in warm weather cities do in fact play slightly worse than expected on the road in very cold weather. (This isn't just lame conventional wisdom, we have done some research on it; I don't have a link, it was in the New York Times a few years ago.) But a Saints win in Philadelphia isn't completely out of the question just because the Saints have been much better at home than on the road during the calendar year of 2013.
So with that out of the way, let's look at what the other numbers tell us about this matchup.
WHEN THE SAINTS HAVE THE BALL
The big story about the Eagles this year has been their improvement in the second half of the season. They started off 3-5, then ended the season going 7-1. The offense has gotten most of the attention, but the defense has also improved steadily and significantly -- although the pass defense improved first, followed by the run defense. Please excuse the arbitrary end points, but this does tell the story:
|Philadelphia Defensive DVOA, 2013|
|Weeks||Pass D||Rk||Run D||Rk||Total D||Rk|
The Saints' passing game is heavily structured around tight end Jimmy Graham, who led all tight ends in receiving DYAR this season. This is where the Eagles' one major injury question may be a big issue. The Eagles started the year with Patrick Chung playing free safety opposite Nate Allen at strong safety. They pulled Chung after three weeks and put in rookie fifth-round pick Earl Wolff, which was one of the big steps towards improving their defense over the second half of the season. Then Wolff hurt his knee, and Chung was back in the starting lineup in Week 11. Wolff was healthy enough to play a little bit at the end of the season, hurt the knee again, and is listed as questionable for Saturday's game.
Chung has had serious problems the past few weeks, both in playing deep safety and when Philadelphia's blitz packages forced him to cover man-to-man, like when Dez Bryant toasted him late in the Week 17 win over Dallas. Now, game charting shows that the Eagles have not tended to use their safeties to cover opposing tight ends. They have been much more likely to use inside linebackers Mychal Kendricks and DeMeco Ryans. However, we're not talking about Rob Housler or Martellus Bennett here. Graham is essentially a wide receiver, who almost never lines up in a stance next to the offensive line. The closest comparison among the tight ends the Eagles have played this year would probably be Antonio Gates or Julius Thomas. The Eagles played those guys back in September, so it is hard to know what their current, improved defense would do against them, but game charting shows that the Eagles used safeties to cover those guys a lot more often than they did to cover other tight ends the rest of the year. If they do that this week, they better be using Nate Allen and not Patrick Chung. Gates dominated the Eagles with eight catches and 124 yards. Thomas wasn't quite as good in Week 4 but did catch all four pass targets for 43 yards.
Of course, putting Chung in deep centerfield may not be the best thing either, given how good Drew Brees is at hitting the deep pass. Deep threat Kenny Stills led all receivers in DVOA, although he barely hit the minimum 50 passes needed to be ranked. A commenter pointed out in the discussion thread for the Quick Reads Year in Review that this may not be an indication that Stills is something special, because the Saints have a history of deep threats with fabulous DVOA ratings, but that's not really anything to make the Eagles defenders feel any better. It doesn't matter if Drew Brees is awesome or Kenny Stills is awesome if the Eagles still have to face Brees-to-Stills. For all the discussion of cold weather, the forecast is for winds to only be 5-6 miles per hour, which isn't really going to mess too much with the deep pass.
The deep pass coverage issues will get even worse if the Eagles blitz Brees. The Eagles don't send as many big blitzes as they used to, which is good, because big-blitzing Drew Brees is not a good strategy. Brees gained 9.3 yards per pass this year against six or more pass rushers, as opposed to 7.3 yards per pass the rest of the time.* However, like most 3-4 defensive teams, the Eagles do send five pass rushers a lot. They sent five 28 percent of the time, compared to a league average of 24 percent. This year there wasn't much difference in Brees' performance against four pass rushers and against five pass rushers, but in past years he's gotten gradually better the more guys you send at him. That's why teams don't blitz him much at all. Brees faced only three or four pass rushers on 74 percent of pass plays this year, third in the NFL behind Peyton Manning and Matthew Stafford. He only faced a defensive back blitz on 7.2 percent of pass plays, the lowest figure in the league, because he also torched those plays for 9.2 yards per pass.*
As far as the shorter passes go, it's time for me to once again say mean things about Cary Williams. His charting numbers this year weren't as bad as last year, but he continues to give up plenty of 10-yard curl patterns right in front of him, and Marques Colston seems like the worst possible receiver for him to cover. Our cornerback charting numbers are not complete yet, but we've got Bradley Fletcher giving up 6.2 yards per pass (13th out of 88 cornerbacks) with 53 percent Success Rate (45th) while Williams gave up 6.8 yards per pass (33rd) with 49 percent Success Rate (66th).
The Saints are actually as surprisingly reasonable running team, when they feel like doing it. The running backs certainly get a little space because Saints opponents are always playing pass. The Saints were 19th in run offense DVOA and seventh in Adjusted Line Yards. One thing the Saints probably don't want to do is run wide to the right. The Saints rank just 27th on Adjusted Line Yards for runs right end, as opposed to seventh overall; the Eagles' defense is second on runs right end as opposed to 17th overall.
WHEN THE EAGLES HAVE THE BALL
The Eagles have definitely improved on offense during the second half of the season, but it isn't like they weren't a good offense in the first two months. The Eagles' pass offense DVOA improved from 21.5% (tenth) in Weeks 1-9 to 41.4% (fourth) in Weeks 10-17. Their run offense DVOA improved from 20.2% (first) to 27.7% (a better first).
Nonetheless, the Eagles have improved significantly in some very important situations.
- The tables above show that the Eagles struggle in the red zone compared to their offense overall, but that hasn't been true since Nick Foles took over the quarterback position for good in Week 10. The Eagles' red-zone offensive DVOA went from -15.1% in Weeks 1-9 to 20.0% in Weeks 10-17.
- The Eagles had 11.2% DVOA on first downs in the first eight games of the year, including 6.2% running the ball. Since Week 10, the Eagles have 39.1% DVOA on first downs, including 40.7% running the ball.
- In the first half of the season, the Eagles had -24.5% DVOA when passing the ball on third or fourth down (27th in the NFL) with a conversion rate of just 27 percent (31st). Since Week 10, they have 36.4% DVOA passing on third or fourth down (ninth in the NFL) with a 41 percent conversion rate (seventh).
The one thing that could mess up Nick Foles on third down is heavy pressure. You know Rob Ryan likes to bring the heat on third down, and the Saints rank fourth against the pass on third or fourth down this season. Their Adjusted Sack Rate goes from 7.4 percent on first/second down (11th in NFL) to 11.4 percent on third/fourth down (second in NFL). The Eagles, meanwhile, give up more sacks on third down. Their ASR, only counting plays with Foles at quarterback, goes from 7.9 percent on first/second down (would be 24th in NFL) to 12.9 percent on third/fourth down (would be 32nd in NFL).
You can also see the success of Ryan's strategy when you look at stats based on number of pass rushers. New Orleans was one of eight defenses to send a big blitz more than 10 percent of the time, and the Saints allowed just 4.6 yards per pass on these plays. However, Nick Foles was insane against big blitzes, albeit with a limited sample size. He faced 21 blitzes of six or seven pass rushers this year and completed 13 of those passes for 12.6 yards per pass. He had three touchdowns and eight other first downs with no sacks or interceptions. (As far as four pass rushers vs. five pass rushers, Foles had slightly higher yards per pass against four pass rushers but converted for a first down slightly more often against five pass rushers.)
Big free-agent signing Keenan Lewis has surprisingly mediocre pass coverage stats in our game charting this year, with 7.0 yards per pass (41st) and 51 percent Success Rate (57th). Corey White's stats are far better, as we have him giving up just 3.8 yards per pass (second) with a 69 percent Success Rate (fifth). However, take those stats with an entire Morton's Salt factory. Right now, we've ranked 88 cornerbacks based on charting so far, players with at least 35 charted targets. White hits the minimum exactly. Our charting numbers are for the majority of the year when he was the nickelback. He's now starting because of an injury to Jabari Greer, and we've learned very well in recent years that players with fabulous stats in small sample size as nickelbacks don't necessarily shine when they become starters. (Honestly, they don't even necessarily shine with a larger sample size as nickelbacks.)
Of course, with the Eagles you always need to look for the screen pass, but the Saints were one of the better defenses in the league against screens, allowing just 5.1 yards per pass (11th in the NFL) and 16.9 total QBR (fifth).*
The Eagles rank first in rushing DVOA on first down, first on second down, and tenth on third or fourth down. The Saints rank fourth in run defense DVOA on first down, making that a matchup of strength against strength. However, their run defense completely breaks down after that. The Saints rank 31st in run defense DVOA on second down and dead last on third or fourth down. That's a real issue against an Eagles team that is surprisingly run-heavy. The Eagles were one of four teams to run on more than half of all second-down plays and one of just three teams to run on more than one-third of all third-down plays. (Note: those numbers include scrambles as runs, not passes.) In fact, the Eagles were more likely to run on second down than on first down (50 percent vs. 48 percent).
The Saints also have particular trouble with the read option, giving up 5.6 yards per carry according to ESPN Stats & Information. The Eagles ran more read options than any other team (304 of their 500 carries, with no other team over 170) and averaged 5.7 yards per carry.*
One interesting split to note: the Saints' defense is far better after halftime (-17.6% DVOA, fourth) than it is before halftime (3.5% DVOA, 20th). This is not an issue of the Saints playing particularly strong defense when they get way ahead, as there is very little difference in their defensive DVOA depending on whether they are winning big, losing big, or in a close game.
These two teams are extraordinarily similar when it comes to special teams. Once we adjust for the fact that the Saints play their home games indoors and the Eagles play outside in a cold-weather city, you end up with the 24th and 25th ranked special teams units. Both teams have been lousy on field goals and kickoffs. Both teams have been a bit below average on punt returns but have returners who have historically shown they can be dangerous (Darren Sproles and DeSean Jackson). Both teams have been average on kick returns, and both teams have been good punting, although the Saints' punts coverage has been better than Philadelphia's. The Saints did get rid of field-goal kicker Garrett Hartley a couple weeks ago, but they replaced him with Shayne Graham, who is the very definition of a waiver-wire, replacement-level kicker. He's not the guy you want to trust to hit a 53-yard field goal when the game is on the line.
I happen to think that the Saints have a better chance in this game than most people seem to give them credit for. These two teams were roughly equivalent over the course of the season; although the Eagles finished a little better over the last few weeks, they weren't that much better. The issue of New Orleans playing on the road is probably a bit overplayed in the conventional wisdom. That being said, the Eagles are still the more likely team to move on. They do still have the home-field advantage, and their run-heavy offense hits the Saints' defense right where they are weakest. The Eagles aren't afraid to run the ball on any down, and the read option gives the Saints problems. Nick Foles has been outstanding in the second half of the season, and doesn't seem to have any problem with the kind of heavy pressure the Saints want to bring at him. To win this game, the Saints are going to need to win one-on-one matchups and bring pressure on Foles with their first four guys instead of trying to beat the Eagles with stunts, games, and overload blitzes. It will also help if they can jump out to a big lead and try to force Chip Kelly to get away from the run, although I'm not sure the Eagles would get away from the run even if they were down two touchdowns in the second half.
San Francisco at Green Bay
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The dominant storyline in this game is that the 49ers seem to be the one team that clearly has Green Bay's number. San Francisco has beaten the Packers three times over the last two seasons, and all three times were in very different ways. They beat Green Bay in Week 1 of 2012 with a big rushing day from Frank Gore and Kendall Hunter, back when Alex Smith was still the 49ers' starting quarterback. They beat Green Bay in last year's postseason when the Packers had no idea how to stop Colin Kaepernick running the read option. And then they won in Week 1 of this season when the Packers came out expecting nothing but zone reads and instead Colin Kaepernick threw the ball for over 400 yards, including 208 yards to Anquan Boldin.
So it's hard to learn much from looking at a single one of these three games. This is particularly true if we want to compare this Packers-49ers game to the one from Week 1 of the current year. The 49ers did not have Michael Crabtree in that game. The Packers had Clay Matthews, but won't have him in this week's game. On the other hand, Colin Kaepernick hasn't even come close to that kind of passing performance the rest of this season.
The other big storyline here is going to be the weather, but I can't imagine that the bitter cold and 15 to 20 mile-per-hour winds are going to affect one team any more than the other. Yes, the 49ers are a California team, but they aren't really a "warm weather" team quite like the Chargers. And let's be honest, the Packers have practiced in some cold weather in the past but the cold on Sunday is going to be nuts. As far as the wind affecting deep passes, the two teams throw deep roughly the same amount. 20.4 percent of Aaron Rodgers' passes this year went over 15 yards through the air; for Kaepernick, that number was 21.3 percent.
WHEN THE 49ERS HAVE THE BALL
Hey, remember when the Packers had a great defense? Not this year. The Packers have been awful in pretty much every area of defense this season. They rank 28th against the pass and 30th against the run. They rank 29th on first downs, 30th on second downs, and 25th on third downs. They're 30th in the red zone. And Green Bay's struggles against the pass are pretty evenly split across the receivers being covered; the Packers ranked 27th against No. 1 receivers, No. 2 receivers, and running backs, and 26th against tight ends. They are a bit better against "other receivers," ranking 10th.
The Packers were sort of okay against the run early in the year, but they've been dismal the last few weeks.
|Green Bay Run Defense, 2013|
That makes things easier if the 49ers do want to establish some sort of running game despite the fact that they've struggled with run blocking this season. The Packers rank 14th in run offense DVOA, but that's because of long runs (fifth in Open Field Yards per carry) and Colin Kaepernick (11.6% rushing DVOA). The 49ers are just 29th in Adjusted Line Yards, with no real trend of improvement or decline over the course of the year. (I wrote more about the strange dichotemy between our line stats and DVOA for the NFC contenders in this post on Thursday.)
You have to imagine that the loss of Clay Matthews will be a problem for the Green Bay pass rush, although, surprisingly, the Packers' Adjusted Sack Rate didn't decline when Matthews was injured for four weeks earlier this season. If losing Matthews makes Dom Capers send even more blitzes than usual, than there really is going to be a problem, because Kaepernick has been fabulous against the blitz this season. Kaepernick has gained 6.6 yards per pass against three or four pass rushers, 7.0 yards per pass against five, and a league-leading 9.3 yards per pass against big blitzes of six or more. And the Packers already like to blitz. Green Bay sends five or more blitzers 37 percent of the time, eighth in the NFL. Kaepernick also gains 9.3 yards per pass against any defensive back blitzes, and the Packers send a defensive blitz on 16.9 percent of passes (second behind the Raiders).
WHEN THE PACKERS HAVE THE BALL
First of all, let's talk a little bit about that Green Bay week-by-week chart to the right. First, you'll notice that while the Packers have declined in recent weeks, one game was way, way worse than the rest. That's the 40-10 Thanksgiving loss to Detroit, where the Packers were outgained 561 yards to 126.
The other thing you'll notice is that last week's win over Chicago to send Green Bay to the playoffs actually had the lowest single-game DVOA of any Packers game this year except for that horrible Thanksgiving debacle. That game had some weird numbers. When the Bears scored, they tended to do so fast. The Bears had only three drives of more than five plays, and none of more than eight. As a result, the Bears gained 7.0 yards per play compared to just 6.2 yards per play for Green Bay, but Green Bay ran 76 plays compared to just 49 for Chicago. Fumble luck also went two different ways. The Bears fumbled twice and lost one of them; the Packers fumbled twice and recovered both, including one where they turned a very negative play (an Aaron Rodgers sack-fumble in the red zone) into an offensive touchdown.
There's no question Rodgers seemed a bit rusty early on in the game, which is why the Packers actually ended up with -6.6% offensive DVOA for the game. However, there was a big difference after halftime when Rodgers got more accurate. Green Bay had -57.0% offensive DVOA before halftime, and then 50.2% offensive DVOA after halftime.
Looking at the splits of advanced stats for the Green Bay offense this year is fairly pointless, because the passing game was so different with and without Rodgers. If we look only at the numbers with Rodgers behind center, the Packers' passing game can basically do no wrong. (Well, except for getting Rodgers sacked a lot.) If we compared Green Bay's numbers with Rodgers with the rest of the league for the whole season, the Packers would rank ninth passing on first downs, second on second downs, and sixth on third or fourth downs.
As for the part about getting Rodgers sacked a lot, the Packers were 26th in Adjusted Sack Rate this season but the 49ers' pass rush declined from its level of 2012, finishing just 29th with an ASR of 6.0%. Of course, a lot of that has to do with the loss of Aldon Smith at midseason. If we only look at the weeks Smith was playing, the 49ers' ASR goes up from 6.0 percent to 6.8 percent, which is actually a bit higher than it was a year ago.
One reason that the 49ers tend to play well against the Packers is that they don't fall into the trap of blitzing Rodgers. Rodgers has been one of the best quarterbacks in the league against the blitz for pretty much his whole career, especially against big blitzes of six or more pass rushers. But the 49ers blitz less than almost any other defense. They send five or more pass rushers on just 19 percent of pass plays, less than any defense except Detroit and Jacksonville, and they only big blitzed on 2.4 percent of pass plays this season. That being said, when the 49ers do big blitz, they do it right. Over the past two seasons, the 49ers have allowed a miniscule 3.3 yards per pass when they send six or more pass rushers.
Thanks to the rise of rookie Eddie Lacy, the Packers should be able to put Rodgers in good down-and-distance situations with regular gains on the ground. The Packers were third in rushing DVOA and fifth in preventing running back stuffs (just 16 percent of runs). The 49ers' defense is average against the run, but particularly weak when it comes to stuffing runners at the line, ranking 31st. However, the 49ers are second preventing Open Field Yards and sixth preventing Second Level Yards, so there probably won't be a lot of long Lacy runs.
It's also important to note that the Packers are better running up the middle, while the 49ers have been much better stopping runs to the outside.
|Adjusted Line Yards by Direction, 2013|
|Team||Left End||Rk||Left Tackle||Rk||Mid/Guard||Rk||Right Tackle||Rk||Right End||Rk|
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Mason Crosby is a great example of just how inconsistent field-goal kickers can be from season to season. Remember last year, when it looked like Crosby couldn't hit the broad side of a barn? Crosby only hit 21 of 36 field goals and was worth -11.8 points below average by Football Outsiders metrics. One year later, Crosby has hit 33 of 37 field goals and has been worth 4.0 points more than the average kicker. As for kickoffs, that's been a weird story. The Packers started the season with punter Tim Masthay on kickoffs, but pulled him after Cordarrelle Patterson returned a kickoff 109 yards for a touchdown on the first play of Week 8. OK, that's bad, but seriously -- you are going to blame Masthay because nobody could tackle Patterson after he put the kickoff within a yard of the back of the end zone? That's ridiculous. So, the Packers put Crosby in, and his kickoffs have not been as good as Masthay's. Not counting deliberate squibs or onside attempts, Masthay averaged 66.5 yards per kickoff with 17 touchbacks in 37 attempts. Crosby averaged 64.1 yards per kickoff with 13 touchbacks in 51 attempts. Lest you think that's just an issue of the weather getting colder, FO metrics which adjust for weather rate Masthay's gross kickoff value as 0.1 points above average, while Crosby is -3.7 points below average.
And yet... Green Bay has actually been much better on kickoffs since midseason because the coverage teams improved dramatically. The Packers allowed ten returns of 30 or more yards on Masthay kickoffs, and only six on Crosby kickoffs. And so, since that Patterson touchdown in Week 8, the Packers have been an average team on kickoff value. They've also gotten good punts from Masthay and good punt returns from Micah Hyde.
Nonetheless, San Francisco has the advantage when it comes to special teams and the field position game. Andy Lee has been the best, most consistent punter in the NFL for the last few years. Phil Dawson has been excellent on both field goals and kickoffs. The 49ers then help their kickers out with very good coverage units. The 49ers don't have good numbers on returns, but a lot of that has to do with the struggles of Kyle Williams, who was cut. LaMichael James has taken over both jobs in the past few weeks and has slightly above-average value on both kickoff and punt returns.
Even after everything Peyton Manning has done this season, there's a pretty good argument that a healthy Aaron Rodgers is the best player in the NFL right now. So it's certainly hard to count the Packers out of any game he plays in. Things are even easier for him now that Lacy gives the Packers a well-rounded offense. However, everything else in this game points towards the 49ers. The Packers' defense is terrible and their special teams are unimpressive. And the 49ers are a well-rounded team, above-average both running and passing, on both offense and defense, and on special teams. San Francisco is the most likely of the four road teams to win this weekend.
DVOA (Defense-adjusted Value Over Average) breaks down each play of the season and compares it to the NFL average based on situation and opponent. You'll find it explained further here. Since DVOA measures ability to score, a negative DVOA indicates a better defense and worse offense, and a positive DVOA indicates a better offense and worse defense.
SPECIAL TEAMS numbers are different; they represent value in points of extra field position gained compared to NFL average. Field goal rating represents points scored compared to average kicker at same distances. All special teams numbers are adjusted by weather and altitude; the total is then translated into DVOA so it can be compared to offense and defense. Those numbers are explained here.
Each team is listed with DVOA for offense and defense, total along with rush and pass, and rank among the 32 teams in parentheses. (If the DVOA values are difficult to understand, it is easy to just look at the ranks.) We also list red zone DVOA and WEIGHTED DVOA (WEI DVOA), which is based on a formula which drops the value of games early in the season to get a better idea of how teams are playing now (explained here).
Each team also gets a chart showing their performance this year, game-by-game, according to total DVOA. In addition to a line showing each game, another line shows the team's trend for the season, using a rolling average of the last five games. Note that even though the chart appears in the section for when each team has the ball, it represents total performance, not just offense.