PRIMER
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.
THIS WEEK
The Seahawks gain a few spots in the rankings by standing still during their bye week. The top 5 teams are beginning to stabilize. San Diego and Arizona are perfect examples of why expert rankings are trash. The Chargers are a top shelf team that has been on the wrong side of some close road losses. The Cardinals are a horrible team that has lucked into some ugly wins. These sorts of aberrations tend to work themselves out by season’s end. Many scoffed at the Chiefs #3 ranking last week, but they went into Indy and gave the Colts everything they could handle. New Orleans continues to struggle, and it’s looking more and more like they are not the team they were last season.
Scatter chart of the rankings. This view helps to give you a view of how teams are grouped together. You will generally see tiers of strength develop as the season wears on. The Top 13 teams have created a strong separation from the rest of the pack. Buffalo, thankfully, is in a class by themselves.