THE POWER RANK

How to rank NFL teams in the preseason

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nfl2014_preseasonYou want to know the strength of your NFL team. You’ll take any analytics that can sort through the preseason noise of the NFL.

In college football, team strength tends to persist from year to year. This makes it possible to use previous seasons to predict the current season.

However, looking at past years does not work in the NFL since team performance regresses to the mean. The salary caps levels the playing field for all 32 teams. Injuries and luck can derail teams with the highest expectations, such as Atlanta in 2013.

However, we can use a different trick from college sports to rank NFL teams in the preseason. Let me explain.

Wisdom of many sports writers

Preseason polls in college sports are remarkable predictors of success.

I first learned about this counter intuitive result from Nate Silver, who uses the preseason AP college basketball poll in his NCAA tournament predictions.

The same accuracy holds for college football polls. In the preseason AP poll that gets released before the season, the higher ranked teams win 59.5% of bowl games that postseason, a result based on 300 bowl games since the 2005 season. The preseason Coaches poll has predicted a more remarkable 61.2% of bowl game winners in the same time span.

The combined wisdom of sports writers or coaches lead to remarkable rankings. However, the accuracy of these polls decrease once the season starts. The writers or coaches tend to react too strongly to wins and losses. By the end of the season, the higher ranked team in the AP polls wins 56% of bowl games.

However, the AP poll is a remarkable tool before the season starts. Let’s created the same type poll for the NFL.

Ensemble NFL preseason rankings

Every major sports media site publishes preseason power rankings. I looked at 20 from before the 2013 season.

A team’s rank isn’t enough to make game predictions. We also need a team’s rating, which gives an expected margin of victory over an average NFL team.

To do this, I took a team’s rank and assigned it a rating based on historical results from The Power Rank. For example, the top ranked team had a 9.7 rating from 2003 through 2012.

Now for each subjective power ranking, a team gets both a rank and a rating, just like the rankings here on The Power Rank. To get ensemble preseason rankings, a team’s rating is averaged over the 20 subjective power rankings. Here are the results for 2013 along with the team’s final record after the playoffs.

1. San Francisco, (14-5), 8.43.
2. Seattle, (16-3), 7.97.
3. Denver, (15-4), 7.35.
4. Atlanta, (4-12), 5.65.
5. Green Bay, (8-8-1), 5.29.
6. Baltimore, (8-8), 4.92.
7. New England, (13-5), 4.89.
8. Houston, (2-14), 4.38.
9. Cincinnati, (11-6), 3.04.
10. Washington, (3-13), 2.25.
11. New York Giants, (7-9), 1.58.
12. New Orleans, (12-6), 1.34.
13. Chicago, (8-8), 1.33.
14. Indianapolis, (12-6), 1.05.
15. Pittsburgh, (8-8), 0.18.
16. Dallas, (8-8), 0.15.
17. Minnesota, (5-10-1), 0.02.
18. St. Louis, (7-9), -0.79.
19. Carolina, (12-5), -1.35.
20. Miami, (8-8), -1.56.
21. Tampa Bay, (4-12), -1.95.
22. Detroit, (7-9), -1.99.
23. Kansas City, (11-6), -2.52.
24. Philadelphia, (10-7), -3.65.
25. Cleveland, (4-12), -4.11.
26. San Diego, (10-8), -4.20.
27. Tennessee, (7-9), -4.42.
28. Arizona, (10-6), -4.46.
29. Buffalo, (6-10), -5.11.
30. New York Jets, (8-8), -6.80.
31. Jacksonville, (4-12), -8.17.
32. Oakland, (4-12), -8.74.

Clearly, the preseason ensemble rankings thought too highly of Atlanta and Houston, two teams that combined for 6 wins in 2013. On the other end, the ensemble rankings missed low on San Diego and Arizona.

However, the rankings had the final four teams in the playoffs (Seattle, Denver, San Francisco and New England) in the top 10. In addition, they did predict 62.5% of game winners over the 2013 regular season and playoffs. The Vegas line gets 66% of games correct on average.

Preseason ensemble rankings for 2014

Here are results for the 2014 season.

1. Seattle, 9.61.
2. Denver, 7.96.
3. New Orleans, 6.58.
4. New England, 6.40.
5. San Francisco, 6.13.
6. Green Bay, 6.07.
7. Philadelphia, 3.72.
8. Indianapolis, 3.42.
9. Cincinnati, 3.10.
10. Chicago, 2.03.
11. San Diego, 1.85.
12. Arizona, 1.20.
13. Baltimore, 1.01.
14. Pittsburgh, 0.78.
15. Carolina, 0.39.
16. Kansas City, 0.30.
17. Detroit, -0.03.
18. Atlanta, -0.99.
19. St. Louis, -1.52.
20. Tampa Bay, -1.63.
21. Miami, -2.13.
22. New York Jets, -2.40.
23. New York Giants, -2.41.
24. Dallas, -3.44.
25. Washington, -3.78.
26. Minnesota, -3.95.
27. Tennessee, -4.60.
28. Houston, -5.56.
29. Jacksonville, -6.02.
30. Cleveland, -6.43.
31. Buffalo, -6.98.
32. Oakland, -8.69.

The rankings in the ensemble differed the most on Houston. The Texans have lots of question marks on offense with new QB Ryan Fitzpatrick. However, they had a decent defense last season and added top draft pick Jadaveon Clowney to a pass rush that already features J.J. Watt. Houston is 28th in the preseason rankings.

The rankings in the ensemble differed the least on Philadelphia. From all the Chip Kelly is a genius articles out there, everyone thinks the Eagles are a solid top 10 team. Philadelphia is 7th in the preseason rankings.

However, the Eagles have issues to worry about. QB Nick Foles can’t possibly throw interceptions at a lower rate than he did last season. Moreover, the pass defense finished 23rd last season in my yards per pass attempt adjusted for schedule stat.

How well do the predictions compare with the line?

We can check how closely the predictions from these rankings compare with the line. Here are the predictions for week 1. The games are ranked by the strength of the two teams and expected closeness of the outcome.

1. Green Bay at Seattle. (0.61)
Seattle (1) will beat Green Bay (6) by 6.1 at home. Green Bay has a 34% chance of beating Seattle.

2. Indianapolis at Denver. (0.53)
Denver (2) will beat Indianapolis (8) by 7.1 at home. Indianapolis has a 31% chance of beating Denver.

3. San Diego at Arizona. (0.52)
Arizona (12) will beat San Diego (11) by 1.9 at home. San Diego has a 45% chance of beating Arizona.

4. Cincinnati at Baltimore. (0.50)
Baltimore (13) will beat Cincinnati (9) by 0.5 at home. Cincinnati has a 49% chance of beating Baltimore.

5. Carolina at Tampa Bay. (0.43)
Tampa Bay (20) will beat Carolina (15) by 0.6 at home. Carolina has a 48% chance of beating Tampa Bay.

6. New York Giants at Detroit. (0.40)
Detroit (17) will beat New York Giants (23) by 5.0 at home. New York Giants has a 36% chance of beating Detroit.

7. New Orleans at Atlanta. (0.38)
New Orleans (3) will beat Atlanta (18) by 5.0 on the road. Atlanta has a 36% chance of beating New Orleans.

8. Minnesota at St. Louis. (0.36)
St. Louis (19) will beat Minnesota (26) by 5.0 at home. Minnesota has a 36% chance of beating St. Louis.

9. New England at Miami. (0.34)
New England (4) will beat Miami (21) by 5.9 on the road. Miami has a 34% chance of beating New England.

10. Washington at Houston. (0.32)
Houston (28) will beat Washington (25) by 0.8 at home. Washington has a 48% chance of beating Houston.

11. Tennessee at Kansas City. (0.31)
Kansas City (16) will beat Tennessee (27) by 7.5 at home. Tennessee has a 30% chance of beating Kansas City.

12. San Francisco at Dallas. (0.29)
San Francisco (5) will beat Dallas (24) by 7.0 on the road. Dallas has a 31% chance of beating San Francisco.

13. Cleveland at Pittsburgh. (0.23)
Pittsburgh (14) will beat Cleveland (30) by 9.8 at home. Cleveland has a 25% chance of beating Pittsburgh.

14. Jacksonville at Philadelphia. (0.22)
Philadelphia (7) will beat Jacksonville (29) by 12.3 at home. Jacksonville has a 20% chance of beating Philadelphia.

15. Buffalo at Chicago. (0.20)
Chicago (10) will beat Buffalo (31) by 11.6 at home. Buffalo has a 22% chance of beating Chicago.

16. Oakland at New York Jets. (0.18)
New York Jets (22) will beat Oakland (32) by 8.9 at home. Oakland has a 27% chance of beating New York Jets.

The predictions differ the most from the line in games with really bad teams. For example, the preseason rankings predict a 10 point win for Pittsburgh over 30th ranked Cleveland. The line only favors Pittsburgh by 6.5.

There are similar differences for games with Oakland, Buffalo and Jacksonville. It seems like the markets do not want to put down the worst teams in the NFL.

Members of The Power Rank have access to these predictions for all 256 games of the NFL season. To learn more, click here.

3 things numbers tell us about the Super Bowl

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The New England Patriots will play the New York Giants in the Super Bowl this Sunday. The Power Rank offers some numbers based predictions on the outcome.

1. It is not 2008. As you might have heard, the Patriots and Giants played in the Super Bowl recently. On February 3, 2008, the Giants pulled off a 17-14 upset over Tom Brady, Randy Moss and the Patriots. While Peter King at SI.com sees many of the same characters this time, this doesn’t mean the teams are similar. The Power Rank gave the 2007 Patriots a 14.7 rating, meaning they were more than 2 touchdowns better than the average NFL team. No other NFL team this past decade has come within 2 points of that year end rating. Our methods predicted that New England would beat New York by 11.1 points in 2008. The Giants cashed in a 19% probability of winning that game. This year, New England has a 8.3 rating, and The Power Rank predicts a point spread of 3.1. The Giants have a 40% chance of pulling the upset.

2. New England’s pass defense really is bad. Many have noted New England’s inability to defend the pass this year. The Patriots ranked next to last in total pass yards given up in the regular season. However, even the best pass defense will give up yards if the opposition throws enough. A better measure of pass defense is yards per pass attempt. But the Patriots don’t look much better by this metric. New England gave up 7.1 yards per pass attempt, 29th out of 32 teams.

3. Expect a lot of points. We also use The Power Rank algorithm to rank offense and defense. These rankings amount to scoring offense and defense that account for strength of schedule. Including the playoffs, New England has scored 32.3 points per game, but we assign an offensive rating of 28.8, still 2nd best in the NFL. This lower rating suggests that New England faced poorer defenses this season. The rating also implies that New England would score 28.8 points against the average NFL defense. New York has scored 25.0 points per game but has a 25.2 offensive rating, 5th best in the NFL. The offense and defense rankings predict a 31.5-28.6 final score for the Super Bowl.

For more content, follow The Power Rank on Twitter.

Related Posts:

—NFL rankings.
—About The Power Rank.
—Can a defense force turnovers?
—The Power Rank featured on KALX Spectrum, the science and technology show on UC Berkeley student radio.

NFL Predictions, Conference Championships, January 22, 2012

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Both games should be exciting, but if you have to pick one of the two games to watch, opt for Baltimore at New England.

1. Baltimore versus New England. (0.58)
New England (2) will beat Baltimore (5) by 4.2 at home. Baltimore has a 37% chance of beating New England.

2. New York Giants versus San Francisco. (0.54)
San Francisco (4) will beat New York Giants (6) by 4.7 at home. New York Giants has a 36% chance of beating San Francisco.

For more content, find The Power Rank on Twitter.

Related Posts:

—About The Power Rank.
—Should Nick Saban have gone for it on 4th down against LSU?
—Can a defense force turnovers?
—College football’s incredibly slow progress towards a playoff.
—The Power Rank featured on KALX Spectrum, the science and technology show on UC Berkeley student radio.

NFL Predictions, Week 17, January 1, 2011

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With so many questions about playoff teams and seedings, we can’t just trust our algorithm to rank games this week. Dallas and the New York Giants play for the NFC East, a game that rightfully ends up 3rd in the rankings anyway. In the AFC, Baltimore and Pittsburgh are vying for the North title while Oakland and Denver’s fighting Tebows can both win the West. The four games involving these teams should get high priority this week, even if Pittsburgh is predicted to beat Cleveland by a touchdown on the road. And seriously, is anyone going to watch Seattle at Arizona, no matter how close the outcome? We should move that game from 2nd to 15th, just ahead of the other NFC West game between San Francisco and St. Louis, the worst team in The Power Rank.

1. Baltimore versus Cincinnati. (0.50)
Baltimore (5) will beat Cincinnati (14) by 2.8 on the road. Cincinnati has a 41% chance of beating Baltimore.

2. Seattle versus Arizona. (0.47)
Arizona (21) will beat Seattle (15) by 0.4 at home. Seattle has a 49% chance of beating Arizona.

3. Dallas versus New York Giants. (0.46)
New York Giants (12) will beat Dallas (13) by 2.2 at home. Dallas has a 43% chance of beating New York Giants.

4. San Diego versus Oakland. (0.42)
San Diego (16) will beat Oakland (26) by 1.2 on the road. Oakland has a 46% chance of beating San Diego.

5. New York Jets versus Miami. (0.41)
Miami (20) will beat New York Jets (19) by 2.1 at home. New York Jets has a 44% chance of beating Miami.

6. Detroit versus Green Bay. (0.38)
Green Bay (1) will beat Detroit (8) by 10.9 at home. Detroit has a 20% chance of beating Green Bay.

7. Tennessee versus Houston. (0.38)
Houston (7) will beat Tennessee (17) by 5.4 at home. Tennessee has a 34% chance of beating Houston.

8. Kansas City versus Denver. (0.37)
Denver (25) will beat Kansas City (23) by 1.6 at home. Kansas City has a 45% chance of beating Denver.

9. Carolina versus New Orleans. (0.32)
New Orleans (2) will beat Carolina (18) by 10.5 at home. Carolina has a 21% chance of beating New Orleans.

10. Chicago versus Minnesota. (0.30)
Chicago (10) will beat Minnesota (30) by 4.3 on the road. Minnesota has a 37% chance of beating Chicago.

11. Washington versus Philadelphia. (0.29)
Philadelphia (9) will beat Washington (24) by 6.2 at home. Washington has a 31% chance of beating Philadelphia.

12. Pittsburgh versus Cleveland. (0.28)
Pittsburgh (6) will beat Cleveland (28) by 7.0 on the road. Cleveland has a 29% chance of beating Pittsburgh.

13. Buffalo versus New England. (0.27)
New England (4) will beat Buffalo (22) by 10.9 at home. Buffalo has a 20% chance of beating New England.

14. Tampa Bay versus Atlanta. (0.20)
Atlanta (11) will beat Tampa Bay (29) by 8.1 at home. Tampa Bay has a 26% chance of beating Atlanta.

15. Indianapolis versus Jacksonville. (0.19)
Jacksonville (27) will beat Indianapolis (31) by 4.8 at home. Indianapolis has a 35% chance of beating Jacksonville.

16. San Francisco versus St. Louis. (0.16)
San Francisco (3) will beat St. Louis (32) by 12.2 on the road. St. Louis has a 18% chance of beating San Francisco.

For more content, find The Power Rank on Twitter.

Related Posts:

—Ranking college football bowl games: a viewer’s guide.
—College football’s incredibly slow progress towards a playoff.
—3 types of college football coaches that got fired.
—The Power Rank featured on KALX Spectrum, the science and technology show on UC Berkeley student radio.

NFL Predictions, Week 16, December 24, 2011

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Houston at Indianapolis must have seemed like a tremendous Thursday night matchup before Peyton Manning got hurt. With the Colts’ struggles this year, this game ranks 15th (out of 16) this week. These new game rankings consider both team strength and an excitement factor from an expected close finish. The game rating next to the matchup has a maximum value of 1. Note the majority of games are on Saturday due to Christmas on Sunday.

1. San Diego versus Detroit. (0.49)
Detroit (12) will beat San Diego (10) by 1.3 at home. San Diego has a 46% chance of beating Detroit.

2. San Francisco versus Seattle. (0.48)
San Francisco (3) will beat Seattle (16) by 4.1 on the road. Seattle has a 37% chance of beating San Francisco.

3. New York Giants versus New York Jets. (0.45)
New York Jets (15) will beat New York Giants (14) by 2.1 at home. New York Giants has a 44% chance of beating New York Jets.

4. Atlanta versus New Orleans. (0.44)
New Orleans (4) will beat Atlanta (8) by 6.2 at home. Atlanta has a 31% chance of beating New Orleans.

5. Philadelphia versus Dallas. (0.44)
Dallas (9) will beat Philadelphia (13) by 3.1 at home. Philadelphia has a 40% chance of beating Dallas.

6. Denver versus Buffalo. (0.41)
Buffalo (26) will beat Denver (22) by 0.7 at home. Denver has a 48% chance of beating Buffalo.

7. Arizona versus Cincinnati. (0.38)
Cincinnati (17) will beat Arizona (20) by 3.5 at home. Arizona has a 39% chance of beating Cincinnati.

8. Chicago versus Green Bay. (0.37)
Green Bay (1) will beat Chicago (11) by 11.0 at home. Chicago has a 20% chance of beating Green Bay.

9. Oakland versus Kansas City. (0.37)
Kansas City (25) will beat Oakland (24) by 1.8 at home. Oakland has a 44% chance of beating Kansas City.

10. Miami versus New England. (0.31)
New England (2) will beat Miami (19) by 10.4 at home. Miami has a 21% chance of beating New England.

11. Jacksonville versus Tennessee. (0.25)
Tennessee (18) will beat Jacksonville (27) by 5.9 at home. Jacksonville has a 32% chance of beating Tennessee.

12. Tampa Bay versus Carolina. (0.24)
Carolina (21) will beat Tampa Bay (28) by 5.6 at home. Tampa Bay has a 33% chance of beating Carolina.

13. Minnesota versus Washington. (0.20)
Washington (23) will beat Minnesota (30) by 5.8 at home. Minnesota has a 32% chance of beating Washington.

14. Cleveland versus Baltimore. (0.16)
Baltimore (5) will beat Cleveland (29) by 13.2 at home. Cleveland has a 16% chance of beating Baltimore.

15. Houston versus Indianapolis. (0.16)
Houston (7) will beat Indianapolis (32) by 9.4 on the road. Indianapolis has a 23% chance of beating Houston.

16. St. Louis versus Pittsburgh. (0.09)
Pittsburgh (6) will beat St. Louis (31) by 13.8 at home. St. Louis has a 15% chance of beating Pittsburgh.