Monday, September 7, 2015

NFL Market Rankings and the Inequities of Playoff Seeding

The Top Five
With the regular season just a few days away, my market based NFL rankings are now up and running. These update daily and are designed to reflect the betting market's ranking of all 32 NFL teams. The rankings themselves use the betting point spreads and over/unders from each game. A simple weighted linear regression is used to reverse engineer a ranking from these pairwise numbers.

The key metric here is Generic Points Favored, or GPF, and it is what you would expect the team to be favored by against a league average opponent on a neutral field. By using the point spreads in conjunction with the over/under, GPF can be further decomposed into its offensive and defensive components (oGPF and dGPF).

For now, there is just a week's worth of point spreads and totals to work with, which is insufficient to create a proper regression analysis amongst the 32 NFL teams. To get enough connections between the teams, you need at least three weeks of data. To fill in the gaps in the meantime, I have used the full season point spreads as published by Cantor Gaming.

This will be my fourth year publishing these rankings for the NFL. When it comes to predicting future wins, they have outperformed a variety of other ranking systems. I am curious to see how they stack up this year against ESPN's revamped Football Power Index.