by Aaron Schatz
Kansas City and the Los Angeles Rams maintain the top two spots in the Football Outsiders DVOA ratings this week, setting up Monday night's DVOA Bowl XVIII. We'll get to that in a moment. First, let's talk about a lot of big movement underneath the Chiefs and Rams, thanks to some big results.
The biggest result was Pittsburgh's Thursday night 52-21 curbstomping of the Carolina Panthers, which earned a single-game DVOA rating of 117.2%. That's the best single game of the year so far. The rest of this year's top individual games:
- 105.3% DVOA: Kansas City over Cleveland 37-21, Week 9
- 91.5% DVOA: Baltimore over Tennessee 21-0, Week 6
- 90.3% DVOA: Chicago over Tampa Bay 48-10, Week 4
- 86.0% DVOA: Denver over Arizona 45-10, Week 7
- 80.7% DVOA: Los Angeles Rams over Minnesota 38-31, Week 4
The huge win moves Pittsburgh all the way up from 11th to fifth in total DVOA; the Steelers are even better, now third, in weighted DVOA, which lowers the strength of their 0-1-1 start. On the other hand, the Panthers divebomb from third overall last week to 12th this week. Their actual DVOA rating went from 23.8% to 9.4%, a drop of more than 14 percentage points.
After the Pittsburgh win, there were four other games with DVOA over or near 60% this week, and they generally resulted in some big moves up and down the DVOA ranks:
- 63.5% DVOA: Buffalo over New York Jets 41-10.
- 61.9% DVOA: Green Bay over Miami 31-12
- 61.5% DVOA: Tennessee over New England 34-10
- 56.8% DVOA: New Orleans over Cincinnati 51-14
With the first game on this list, the Jets dropped from 23rd to 27th while the Buffalo Bills climbed out of the bottom spot in DVOA for the first time all season. In a bigger story, the Bills jumped out of last place in the "worst offense we've ever tracked through this point in the season" sweepstakes. I'm afraid that Matt Barkley kind of ruined my fun with his big game against the Jets -- who somehow still have an above-average defense, falling from seventh to 13th in defensive DVOA this week. Buffalo had its first positive offensive day of the year, 50 percentage points of DVOA better than any game they had previously. But one game can't make those first nine go away! The Bills are still on the list, though they are now fifth. And three spots below them, you'll find the Arizona Cardinals. So that's two historically bad offenses once we adjust for the overall scoring environment of the 2018 season.
|WORST OFFENSIVE DVOA
THROUGH 10 GAMES, 1986-2018
|*Arizona is only at 9 games.|
With the second game on this list, Green Bay climbed from 13th to 10th while Miami fell from 14th to 20th. Miami has now fallen from sixth in DVOA to 20th in four weeks.
With the third game on this list, Tennessee climbed from 22nd to 16th while New England fell from sixth to 11th. This is the first time the Patriots have ranked outside the DVOA top ten during the second half of the season since the 2008 Matt Cassel team. It's the first time that a Tom Brady Patriots team has ranked outside the top ten in the second half of the season since the 2005 Patriots finished the year 12th overall.
With the fourth game on this list, Cincinnati fell from 17th to 21st while the New Orleans Saints... only went up from seventh to sixth. The actual rating increase was more impressive, going from 13.8% to 18.4%. But I will fully admit to being a little confused myself as to why the DVOA ratings this year disagree with many other advanced metrics around the Web as far as how good the Saints are. The problem is on offense, where the Saints are sort of the opposite of the Kansas City Chiefs. The Chiefs have one of the best offenses we've ever tracked, because DVOA loves the Chiefs offense more than any other metric out there. But it seems to rate the New Orleans offense lower than any other metric out there. The Saints are on pace to score on a record 61 percent of their offensive drives. Yet in DVOA, the Saints offense is behind not only the Chiefs but also the Rams and Chargers.
I'm going to jump into the weeds a little bit to try to figure out why. This is kind of tough. DVOA is not a simple math formula like passer rating, where A + B + C + D = Rating and it's easy to look and figure out which of the four variables is abnormally high or low. DVOA is breaking down every single play, and I can't go through and say "this 31-yard play is too high and this 16-yard play is too low" for hundreds of plays for each team. But let's look at some possible reasons why DVOA likes the Chiefs so much but not the Saints. Some of these are strengths of DVOA. Some are weaknesses. Maybe I shouldn't be admitting the weaknesses, but we've always been pretty honest about talking through our methods around here.
First, what I think is one of the strengths of DVOA: team DVOA adjusts for playing in domes vs. outdoors. Some of what's going on here is that adjustment. Here's a look at the top six teams in offensive DVOA with what DVOA would look like without the dome adjustment:
|Team||w/o Adjustment||with Adjustment|
Notice that without the dome adjustment, the Saints would at least move up to No. 3. No, I don't know why the adjustment hits the Saints so much harder than the Falcons. That's one of those things that's in the weeds, because the dome adjustment is different for different down-and-distance categories and different for rushing than it is for passing. New Orleans has also played six dome games, Atlanta only five.
(To try to answer questions you might have, in the interest of full disclosure: Right now, there's no adjustment for warm weather vs. cold weather, because last time I worked on DVOA I found that DVOA was basically the same outdoors in both warm-weather and cold-weather cities. That did not take into account specific weather in specific games, though. One of those things that I always plan on working on some more in the future. Also, I've never had the time to add a dome adjustment into our individual stats, which helps explain why Drew Brees is closer to Patrick Mahomes in passing DVOA than the Saints are to the Chiefs in pass offense DVOA.)
Schedule strength is part of what's going on here. The Chiefs have faced the No. 3 toughest schedule of opposing defenses according to DVOA, while the Saints have faced the No. 26 schedule. Of course, other advanced metrics that have the Saints offense ahead of the Chiefs offense also account for schedule strength too.
There's a small amount of discounting what happens in blowouts. DVOA discounts any play in the fourth quarter with the offense winning by over 21 points. The Saints have more of these plays than the Chiefs, and perform better on these plays. Those plays are accounted for in some other metrics more than in DVOA. However, we're talking about less than 50 plays for each team.
Next, an element that is not a good explanation for the offensive DVOA difference between these teams: fumbles. DVOA is not correcting for the Saints having good fumble luck because it's actually the opposite. The Saints have had bad fumble luck, recovering only 3 of 10 fumbles on offense. And the Chiefs have had good fumble luck, recovering 7 of 8 fumbles on offense, though that's mostly aborted snaps which are the fumble type least likely to be recovered by the defense.
Some of what's going on with these teams has to do with a play-by-play metric versus a drive-based metric. I noted earlier the stat about the Saints scoring on such a high percentage of drives. The Saints also lead the league with a 54 percent success rate, with the Rams at 52 percent and the Chiefs third at 49 percent. But the Saints are not at the top of the league in yards per play. Not counting spikes and kneels, the Rams (7.08), Chiefs (7.07), and Chargers (7.06) are basically tied for first place in yards per play. The Saints are more than a half-yard behind at 6.46.
That's connected to a big difference between the teams in average yards to go. Kansas City averages 8.8 yards to go, higher than the NFL average of 8.6. New Orleans averages just 7.9 yards to go, the lowest figure in the league. Remember, DVOA is about comparing success on plays to a league-average baseline. The fewer yards to go, the easier it is to achieve success, and thus the higher the baseline that you are trying to surpass.
This is really a big issue on third downs. The Chiefs have 53.9% DVOA on third and fourth down. They average 7.4 yards compared to 7.4 average yards to go. The Saints have 12.8% DVOA, averaging just 4.7 yards compared to an average of just 5.3 yards to go.
So, how do the Saints get those lower average yards to go numbers? They average more yards on first down, 7.3 compared to 7.0 for the Chiefs. But a bigger issue is an element that's mostly missing from DVOA, and this may be one of DVOA's weaknesses. The issue is penalties. Only certain penalties are included in DVOA because I never figured out a good way to include repeat-the-down penalties such as offensive holding and other illegal blocks. And the biggest difference between the Chiefs and Saints is in offensive penalties. The Chiefs lead the league with 84 accepted penalties on offense. The Saints are 30th with just 48 accepted penalties on offense.
Normally, this isn't a big issue in DVOA. Penalties don't predict the future as well as yardage does, and usually you see the effect of penalties in DVOA because teams mostly get stuck in (and fail to succeed in) third-and-long. The Chiefs are sort of breaking the system with this because they keep overcoming all their offensive penalties with enough yardage to move the sticks. Last week's super-high DVOA against Cleveland is a good example of this. Because of penalties, the Chiefs average yards to go were at 10.1 for the game. It didn't matter, because they just kept converting and moving the chains. There was a 95-yard touchdown drive with 20 yards of penalties and a 90-yard touchdown drive with 15 yards of penalties. In effect, DVOA kept seeing them moving the ball on first-and-20, third-and-19, and so on, and compared that to the average performance in those types of situations and said "this is awesome." For the most part, it wasn't penalizing the Chiefs for getting into those first-and-20 situations in the first place. Something for me to work on and test in the future.
Of course, that's still more of an explanation for the Chiefs' rating than for the Saints' rating. We'll have to keep exploring how these teams play in the future. But hopefully all this going behind the curtain of DVOA helps explain why the Kansas City Chiefs are now the No. 2 offense in DVOA history through ten games...
|BEST OFFENSIVE DVOA
THROUGH 10 GAMES, 1986-2018
... and are also on the list of the best overall DVOA teams through ten games. Watch out, here come the 1987 San Francisco 49ers! They won games 10-12 (which were technically Weeks 14-16) by a combined score of 124-7.
|BEST TOTAL DVOA
THROUGH 10 GAMES, 1986-2018
|*No strike games included.|
Quickly getting back to this week's DVOA Bowl, this is the fourth year in a row where we've had a No. 1 vs. No. 2 matchup late in the season. Interestingly, the No. 2 team has won the last five DVOA Bowls. Here's a look at all of the times we had a DVOA Bowl during the regular season, going back to 1989. Lucky me, I got to just recycle this table from last year's Week 13 commentary! Note that this is total DVOA instead of weighted DVOA, and it does not include 1986-1988.
|DVOA Bowl: No. 1 vs. No. 2 in Regular Season, 1989-2018|
|1996||7||GB||59.5%||5-1||SF||32.4%||4-1||GB||Green Bay, 23-20 (OT)|
|1996||15||GB||34.8%||10-3||DEN||33.0%||12-1||GB||Green Bay, 41-6|
|2007||9||NE||73.6%||8-0||IND||48.7%||7-0||IND||New England, 24-20|
|2008||10||NYG||36.3%||7-1||PHI||35.5%||5-3||PHI||New York Giants, 36-31|
|2009||2||PHI||98.0%||1-0||NO||75.0%||1-0||PHI||New Orleans, 48-22|
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Stats pages should now be updated through Week 10, including playoff odds, the FO Premium DVOA database and snap counts. Note that the playoff odds simulation was done before this Monday's Chiefs-Rams game was moved back to Los Angeles, so it doesn't reflect that the Rams will have home-field advantage in that game.
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These are the Football Outsiders team efficiency ratings through ten weeks of 2018, measured by our proprietary Defense-adjusted Value Over Average (DVOA) system that breaks down every single play and compares a team's performance to the league average based on situation in order to determine value over average. (Explained further here.)
OFFENSE and DEFENSE DVOA are adjusted to consider all fumbles, kept or lost, as equal value. SPECIAL TEAMS DVOA is adjusted for type of stadium (warm, cold, dome, Denver) and week of season. As always, positive numbers represent more points so DEFENSE is better when it is NEGATIVE.
WEIGHTED DVOA represents an attempt to figure out how a team is playing right now, as opposed to over the season as a whole, by making recent games more important than earlier games.
To save people some time, please use the following format for all complaints:
<team> is clearly ranked <too high/too low> because <reason unrelated to DVOA>. <subjective ranking system> is way better than this. <unrelated team-supporting or -denigrating comment, preferably with poor spelling and/or chat-acceptable spelling>
- NON-ADJUSTED TOTAL DVOA does not include the adjustments for opponent strength or the adjustments for weather and altitude in special teams, and only penalizes offenses for lost fumbles rather than all fumbles.
- ESTIMATED WINS uses a statistic known as "Forest Index" that emphasizes consistency as well as DVOA in the most important specific situations: red zone defense, first quarter offense, and performance in the second half when the score is close. It then projects a number of wins adjusted to a league-average schedule and a league-average rate of recovering fumbles. Teams that have had their bye week are projected as if they had played one game per week.
- PAST SCHEDULE lists average DVOA of opponents played this season, ranked from hardest schedule (#1, most positive) to easiest schedule (#32, most negative). It is not adjusted for which games are home or road.
- FUTURE SCHEDULE lists average DVOA of opponents still left to play this season, ranked from hardest schedule (#1, most positive) to easiest schedule (#32, most negative). It is not adjusted for which games are home or road.
- VARIANCE measures the statistical variance of the team's weekly DVOA performance. Teams are ranked from most consistent (#1, lowest variance) to least consistent (#32, highest variance).