Week 15 DVOA Ratings

by Aaron Schatz

After a week of close games and upsets, Philadelphia is back on top of the Football Outsiders DVOA ratings. Conventional wisdom is coming around to agree with DVOA's constant season-long support for the Eagles, but they still may not even make the postseason. It's also important not to fetishize the idea of which team is "number one." After Philadelphia's win over New York knocked the Giants down from first to fourth, we're left with four teams so close at the top that we practically have a four-way tie. The two hottest teams in the NFL rank fifth (Pittsburgh) and sixth (Carolina). When the playoffs finally get here, it really is anybody's ballgame. The 2008 standings are a lot similar to the 2006 standings. That year also had no dominant team, with seven teams at 20% DVOA or higher through 15 weeks.

Going back to 1995, there are only two seasons where the best team as of Week 15 had a lower DVOA than Philadelphia does this year: 1997 (San Francisco at 30.4%) and 2003 (Kansas City at 29.8%).

While the top ten teams in regular DVOA are the same as the top ten teams in weighted DVOA, we can see some trends. Carolina and Indianapolis both have clearly improved over the past few weeks. Lower down, Houston and especially Kansas City are getting stronger and offering fans hope for 2009. On the other hand, Green Bay, Chicago, Washington, Arizona, and Denver have all faded a bit in the second half of the season. Buffalo has really dropped off. The Jets are sort of interesting -- their weighted DVOA is higher than their total DVOA because of bad losses in Weeks 2-3. Our short-term memory thinks of them as fading because of their losses to Denver and San Francisco, but weighted DVOA gives primary weight to the last eight weeks and that period also includes their strongest games, particularly the win over Tennessee and the 47-3 blowout of the pathetic Rams.

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Clearly the defining characteristic of this season is the imbalance between the divisions. The NFC West and AFC West are abysmal, and the AFC East has three mediocre teams that have put together 9-5 records in part because they've picked on the teams from those two western divisions. The Patriots may become only the second team in history to go 11-5 and not make the playoffs, and the other one (the 1985 Broncos) played when there were just two wild cards.

I decided to try a little experiment: What would this season look like if the eight NFL divisions were balanced? We put together a "pretend" NFL by taking the 16 teams in each conference and matching them up based on current DVOA rating. For example, one division consists of the AFC teams currently ranked first (Baltimore), fifth (Miami), 12th (Cleveland), and 16th (Oakland). I assigned each division to play another division in their own conference and a division in the other conference. The final two games were based on last year's records. For example, Baltimore would have ranked second if these four teams had been a real division last year, so they play against AFC Division 4 (BUF, HOU, IND, NE), NFC Division 2 (DAL, NO, NYG, SEA), and the two teams that would have finished second in AFC Divisions 2 and 3, Jacksonville and Denver.

There are two versions of the simulation. The first simulation [1] includes an adjustment for "luck" based on how each team's actual win total differs from the Pythagorean projection. If the divisions were balanced, that doesn't suddenly mean that Philadelphia wouldn't have spent the first half of the year blowing close games with bad short-yardage runs, it doesn't mean that Denver wouldn't have gotten away with some close wins, and so on. The second simulation [2] is only based on DVOA, with no adjustment.

With balanced divisions, the playoffs would include some of those good teams that are going to be left out in the real world. In both simulations, the AFC playoff teams are the same: Baltimore, Tennessee, Pittsburgh, and Indianapolis, with Miami and the New York Jets as the wild cards. The NFC divisions go to the New York Giants, Carolina, Philadelphia, and Tampa Bay, with Atlanta and either Minnesota or New Orleans as wild cards. In each simulation, Arizona, Denver, and New England are stuck at home the majority of the time. You can also see where the ability to win close games (or, alternately, the serendipity to win close games) would affect the postseason races. In the "luck adjustment" version, Baltimore and Miami are basically tied atop AFC Division 1; in the other simulation, Miami is clearly in second place. The Dolphins also show how last year's finish can affect schedule, even though it only changes two games. In our simulated league, Miami plays Cincinnati and Kansas City as its two final games. Despite balanced divisions, they still have a very easy schedule.

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For Premium subscribers, we have a new -- and very commonly requested -- view now available in the DVOA database, which will show you how DVOA would have looked through any week of any season back to 1995. Each week's data is based on opponent adjustments as they looked at the time, so Week 6 would have opponent adjustments at 60 percent strength and based only on the first six weeks, not the entire season. Now you can follow along with the "Worst DVOA Ever" watch or, if you prefer, figure out which teams had the best offense through Week 15, or the best defense through Week 9, or anything else you are interested in.

UPDATE 11:30pm EST: All stats pages are now updated. I have no idea why the FUTURE SCHEDULE columns came out weird, so I just removed them. They don't really mean much anyway with just two games left.

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These are the Football Outsiders team efficiency ratings through 15 weeks of 2008, 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 [3].)

OFFENSE and DEFENSE DVOA are adjusted to consider all fumbles, kept or lost, as equal value. These ratings also include opponent adjustments. SPECIAL TEAMS DVOA is adjusted for type of stadium (warm, cold, dome, Denver) and week of season. WEIGHTED DVOA is adjusted so that earlier games in the season become gradually less important. It better reflects how the team is playing right now.

As always, positive numbers represent more points so DEFENSE is better when it is NEGATIVE.

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 gives performance without adjustments for schedule strength, fumble recovery luck, and weather/altitude on special teams.
• ESTIMATED WINS [4] 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.
• VARIANCE [5] 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).

Worst DVOA Ever Watch

For all the talk about how there are so many really awful teams this year, the fact remains that there are only two historically bad teams: St. Louis and Detroit. The gap between Oakland (30th) and St. Louis (32nd) is equivalent to the gap between, for example, Pittsburgh (5th) and the Jets (17th). Detroit may be the team that finishes 0-16, but according to DVOA, the Rams are worse -- now the second-worst team in DVOA history. The Lions' near-win over the Colts vaulted them up a few spots on the list of the worst teams ever, although their defensive DVOA actually got worse in this game and still ranks as the worst of all time.

In retrospect, the Rams' 34-14 win over Dallas in Week 7 is just incredible, Brad Johnson or no Brad Johnson. The Rams' DVOA in that game is 64%. Their 19-17 win over Washington was a bit lucky, and the Dallas win is the only time all year St. Louis has put up a DVOA over -10%. The Rams have six games with DVOA below -70% and nine with DVOA below -40%. By comparison, the Lions have two positive games (both losses to Minnesota, 12-10 and 20-16) and two other games that are negative in single digits (27-23 loss to Chicago in Week 9 and this week's loss to Indianapolis). The Lions have four games below -70% and seven below -40%.