Power rankings are always debatable. I don't buy into the gut feel methods most places use to determine their rankings, so I developed a formula a few years back that attempts to take at least some of the subjectivity out of the discussion. My approach is simple, I measure offensive and defensive efficiency based on the Yards Per Carry (YPC) and Yards Per Attempt (YPA), as well as points scored and points allowed. The formula to calculate "Team Strength" is as follows:
(YPC (offense) + YPA (offense) + Avg Pts/Game Scored) - (YPC (defense) + YPA (defense)+ Avg Pts/Game Allowed)
The formula has proven to be a pretty accurate predictor of success. Even in the first week of the 2008 season, 5 of the top 10 ranked teams were playoff bound. As with any statistic, it becomes more meaningful as the sample size grows. Usually, these become most meaningful after Week 3. In 2007, 9 of the top 10 ranked teams were playoff teams, with the lowest ranked playoff team coming in at #15. In 2008, 8 the top 10 were playoff teams, with Arizona being the lowest ranked playoff team at #19. I'm not sure any formula could have predicted their run.
If you'd like to see how teams rankings changed from 2008 to 2009, you can read more here.
I have switched over to sharing the rankings via Google Docs, so hopefully, they are still readable.
The Seahawks make their debut at #2 this year, but keep in mind they started out as #1 last year. On the flip side, the Saints started out at #3, and I seriously doubt you'll find another system that had them ranked that high, that fast last year. The Jets were #4, Dallas #5, Baltimore #6 and Minnesota #7. The lowest ranked team in the first week to make the playoffs was Arizona at #18. So while it is clearly less reliable of a system in the beginning, it is much better to be up high than down low.
Scatter chart of the rankings. This will be symmetrical after one game, but will change as the season wears on: