Thursday, November 13, 2008

Today's Lesson: Why Power Rankings Can't Be Done By Numbers


The beautiful thing, as we all know, about power rankings is that they are completely in the eye of the beholder. There is no statistical formula one can use to generate a way to rank NFL teams, 1-32. 
So naturally, I tried. 
I took the approach that stats are completely meaningless; it's all about what you do in the games themselves. So, I put every game that every team has played on a scale. It goes as follows:

You get 1 point if your opponent has won 3 games or less, 2 if they have won 4 or 5, and 3 if they have won 6 or more.
You get 1 point if you lose by 10 or more, 2 points if you lose by 9 or less, 3 points if you win by 9 or less, and 4 points if you win by 10 or more. 
You get 1 point if you play on the road.

So, you can get a maximum of 8 points if you kill a great team on the road (see Dolphins vs Patriots, week 3). You can get a minimum of 2 points if you get killed by a terrible team at home (see Seahawks vs. 49ers, week 9). The results were as follows:

1. Tennessee: 51
2. Carolina: 50
3. Pittsburgh: 50
4. Tampa Bay: 50
5. Philadelphia: 50
6. Arizona: 49
7. Chicago: 49
8. San Diego: 49
9. New York Giants: 48
10. Baltimore: 48
11. Green Bay: 48
12. Atlanta: 47
13. Indianapolis: 47
14. Dallas: 47
15. Miami: 46
16. Buffalo: 46
17. New Orleans: 46
18. New York Jets: 45
19. Washington: 45
20. Minnesota: 45
21. Cleveland: 45
22. New England: 44
23. Jacksonville: 44
24. Kansas City: 44
25. Denver: 43
26. Houston: 42
27. St. Louis: 42
28. Cincinnati: 41
29. Oakland: 40
30. Seattle: 39
31. San Francisco: 39
32. Detroit: 34

I bolded the 10 teams that were the biggest surprises: the 10 whose difference between their standing in these power rankings and in mine is more than 7 points.


The one that catches the eye, of course, is the New York Giants. Many feel that they are the best team in the league, and for anyone to have them outside of the top two is insane. I feel the same way, but the numbers don't. The Giants are so low primarily because of their schedule. There are nine "1-point" teams in the league (teams with 3 or fewer wins). The Giants have played 5 of them. Second, the Giants are lower than you expect because they have only played 2 "3-point" teams. Watching the games as a spectator, you know the Giants cleaned up in both of those games. The final scores don't reflect that, though: they only beat the Redskins by 9 and the Steelers by 7. Of course, dragging their whole score down is the Cleveland game, which only got them 3 points. If they had blown out Cleveland in that game like they should have, we wouldn't be talking about this because the Giants would be tied with Tennessee for first. 

The two biggest differentials are the San Diego Chargers and the New England Patriots. Ironically, this ranking has the Chargers 8 and New England 22; mine has them flip-flopped. Both have a differential of 14. How could this be? New England is 6-3, and San Diego has seemingly struggled to get to 4-5. San Diego is boosted by no low scores. They've only played two "1-point" teams, and have beaten both. Meanwhile, they have two 7-point wins: home blowouts against the Jets and the Patriots. New England, meanwhile, gets punished for their lack of resounding defeats. They only beat the Chiefs by 7, the 49ers by 7, and the Rams by 9. If they could have boosted those margins up to 10 apiece, then New England would be sitting at number 13, and, once again, this discussion would not be taking place. The blow-out to Miami didn't help, either. 


Of course, a couple of these may have corrected me. Kansas City doesn't deserve to be 24th, but they may deserve 26th. Of all the really bad teams in the league, at least they've been playing really good teams close.  I had the Jets in the low teens all year, and this week I finally moved them up. These rankings suggest that that was premature. Perhaps also I am not giving Tampa enough credit for the schedule they played. 

Take what you want from this. By no means am I saying that these rankings are good, much less correct. I'm just telling you what the numbers tell me. If anything, I'm telling you to trust your eyes in the NFL. The Giants may have played a weak schedule, but they've looked great doing it. Most of all, I'm saying that the fate of football teams at any level should be determined by a computer system. You got the allusion there? Good. 

(Photo Credits: AP)

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