Tuesday, December 11, 2012

New Power Rankings Formula

I read a great article on ColdHardFootballFacts.com yesterday about the Seahawks, and why they are so dangerous. There was one gem in there about predicting championship teams. The article mentioned passer rating differential as the "mother of all stats." A full 69 of 72 champions have ranked in the Top 10 in this statistic. It is a stat after my own heart, as I believe offensive and defensive efficiency is the key measurable outside of point differential. Turnovers would factor in there as well, but I am not convinced a team has as much control over that. My power rankings use YPA and YPC differentials. I went ahead and replaced the YPA with offensive and defensive passer rating, to give me this:

(YPC (offense) + Passer Rating (offense) + Avg Pts/Game Scored) - (OPP YPC (defense) + OPP Passer Rating (defense)+ OPP Avg Pts/Game)

The following are the results:



The column on the right shows which teams were helped or hurt by the new calculation when compared to the rankings I released this morning. The number indicates how many spots the team moved up or down in the rankings. The teams that were helped the most were Buffalo (+9 spots) and the Packers (+8). The teams hurt the most were the Vikings (-7) and Giants (-6). The Patriots fell a surprising four spots to 5th overall.

Making this change appears to have added more weight to quality defenses, especially quality secondary play. That happens to align better to my belief about determining the strength of a team, so I will likely switch to this new system going forward.

The scatter chart below shows the tiers of strength based on this new formula.

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