by Aaron Schatz and Danny Tuccitto

Despite their close loss to Cincinnati, the Buffalo Bills continue to lead the Football Outsiders DVOA ratings after four weeks. The Bills are in a close pack of teams at the top that also includes their division rivals in New England and the surprising Tennessee Titans (who will be the subject of an ESPN column later this week). Green Bay is right behind those three AFC teams in DVOA, but ranks first in our "estimated wins" metric because they've been particularly strong in red zone defense and in the second half of close games. The undefeated Packers also rank second in DAVE, which accounts for both DVOA and our preseason projections, and the Packers are currently the leading candidate to win this year's Super Bowl with a 15.7 chance according to the Football Outsiders playoff odds.

Week 4 is when we introduce opponent adjustments into our formula for the first time. The hardest schedules so far have belonged to Denver and Oakland; the easiest have belonged to Tennessee, Atlanta, and the New York Giants. The Giants rank 32nd in schedule so far and first in schedule remaining. (Note that the schedule ratings are based on DVOA, not DAVE.)

The biggest gap between DVOA and non-adjusted VOA belongs to Detroit, which explains why the undefeated Lions are ranked just ninth in DVOA. Not only have the Lions had the league's 26th-ranked schedule, but they've also fumbled the ball five times on offense without losing one. The Lions actually have a below-average -12.6% DVOA for their narrow Week 3 win over Minnesota and a 1.6% DVOA for this week's win over Dallas.

For your enjoyment this week, we have a couple of graphics that Danny Tuccitto has been working on. With teams like Buffalo and Tennessee surprising so early, we were curious at what point early-season DVOA really established how good teams would be for the entire season. The answer appears to be "pretty early." This graphic shows you the correlation of DVOA after a certain week to final DVOA. The black line right above 0.7 represents when r^2 passes 0.5 -- in other words, when the current early-season DVOA accounts for at least 50 percent of the variability in the final DVOA. As you can see, offensive DVOA and total DVOA pass that line as of Week 4. So there's a pretty good chance that teams like Buffalo, Tennessee, and Detroit are going to be good all year. The correlation is even pretty high after Week 3 -- before opponent adjustments are applied. (We should note that, obviously, final DVOA does include the first four weeks of games, which is one of the reasons the correlation is so high.)





This next graphic looks instead at the correlation of weekly DVOA to final wins. This one will be lower, of course, because at the end total DVOA won't correlate exactly with wins the way it will with itself. Still, this shows that you can explain 50 percent of the variability in final win total with DVOA as of Week 7.





Anyway, on to the ratings. All stat pages are now updated through Week 4. The FO Premium database of DVOA splits is updated as well.

For the many people asking, we're trying to get the midseason KUBIAK update out by Thursday.

* * * * *

These are the Football Outsiders team efficiency ratings through four weeks of 2011, 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.

Opponent adjustments are currently at 40 percent strength and will steadily grow stronger until Week 10. As always, positive numbers represent more points so DEFENSE is better when it is NEGATIVE.

DAVE is a formula which combines our preseason projection with current DVOA to get a more accurate forecast of how a team will play the rest of the season. Right now, the preseason projection makes up 40 percent of DAVE.

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>

TEAM TOTAL

DVOA LAST

WEEK TOTAL

DAVE RANK W-L OFFENSE

DVOA OFF.

RANK DEFENSE

DVOA DEF.

RANK S.T.

DVOA S.T.

RANK 1 BUF 35.4% 1 19.9% 4 3-1 39.2% 3 5.6% 14 1.9% 12 2 TEN 33.4% 2 12.2% 10 3-1 26.1% 6 -10.9% 4 -3.6% 25 3 NE 33.1% 5 31.6% 1 3-1 44.8% 1 15.0% 27 3.3% 10 4 GB 29.7% 8 22.4% 2 4-0 39.2% 2 8.3% 18 -1.3% 19 5 BAL 24.2% 3 20.2% 3 3-1 -1.1% 22 -30.1% 1 -4.9% 29 6 NYG 23.4% 6 16.8% 5 3-1 21.4% 8 -2.7% 9 -0.7% 17 7 HOU 21.5% 9 15.7% 8 3-1 26.7% 5 11.1% 21 5.9% 6 8 NO 20.6% 13 16.3% 6 3-1 25.4% 7 6.8% 17 2.0% 11 9 DET 17.3% 4 9.4% 11 4-0 4.4% 15 -14.4% 3 -1.5% 20 10 NYJ 15.3% 7 16.2% 7 2-2 -15.1% 29 -16.5% 2 13.9% 1 11 SF 14.6% 12 6.1% 14 3-1 -3.4% 23 -5.0% 7 13.1% 2 12 OAK 11.7% 10 1.2% 19 2-2 32.8% 4 17.0% 28 -4.1% 28 13 TB 10.8% 19 3.5% 15 3-1 15.5% 10 13.3% 25 8.7% 4 14 CIN 10.4% 11 1.6% 18 2-2 0.7% 19 -9.9% 6 -0.2% 15 15 WAS 9.6% 15 1.6% 17 3-1 -0.4% 21 -10.4% 5 -0.4% 16 16 ATL 4.9% 16 6.5% 13 2-2 6.3% 14 1.2% 10 -0.1% 14 TEAM TOTAL

DVOA LAST

WEEK TOTAL

DAVE RANK W-L OFFENSE

DVOA OFF.

RANK DEFENSE

DVOA DEF.

RANK S.T.

DVOA S.T.

RANK 17 DAL 1.6% 21 -1.8% 21 2-2 1.7% 17 -3.7% 8 -3.8% 26 18 MIN 0.5% 14 -0.7% 20 0-4 3.9% 16 9.6% 20 6.2% 5 19 PIT -0.2% 17 12.8% 9 2-2 0.8% 18 4.8% 12 3.8% 9 20 SD -2.7% 23 7.3% 12 3-1 10.5% 12 9.3% 19 -3.9% 27 21 CLE -5.6% 18 -4.1% 22 2-2 -4.6% 24 6.8% 16 5.8% 7 22 ARI -11.9% 20 -13.6% 25 1-3 0.5% 20 13.7% 26 1.3% 13 23 CHI -12.9% 28 -5.0% 23 2-2 -12.3% 27 12.3% 23 11.7% 3 24 PHI -13.1% 22 1.8% 16 1-3 11.0% 11 21.6% 32 -2.6% 22 25 DEN -15.3% 25 -15.0% 26 1-3 -6.9% 25 13.3% 24 4.9% 8 26 CAR -15.8% 24 -15.2% 27 1-3 16.2% 9 19.2% 30 -12.8% 32 27 MIA -16.0% 26 -6.1% 24 0-4 8.2% 13 21.5% 31 -2.6% 23 28 SEA -24.0% 29 -23.2% 30 1-3 -11.0% 26 6.5% 15 -6.4% 30 29 IND -30.0% 27 -23.0% 29 0-4 -14.4% 28 4.8% 13 -10.7% 31 30 KC -36.1% 32 -26.5% 31 1-3 -23.5% 31 11.6% 22 -1.0% 18 31 JAC -38.3% 30 -22.2% 28 1-3 -31.1% 32 4.2% 11 -3.0% 24 32 STL -40.5% 31 -29.8% 32 0-4 -21.1% 30 17.3% 29 -2.1% 21

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.

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.

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.

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.

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).