ESPN’s Predictive Football Power Index

ESPN has ranked USC #15 in its early 2018 season predictions. Why 15? Why right behind Miami and ahead of Mississippi State? How does ESPN come up with this projection? It’s a more calculated and by-the-numbers analytical than you might think. So much for gut reactions.

ESPN’s Football Power Index (FPI) emphasizes the following four factors in evaluating a team’s rank for this season. First developed by ESPN in 2013, the pre-season FPI is not a playoff predictor, because it does not consider schedule strength.

ESPN claims that if you looked behind the curtains of how Vegas odds are set, you’d see a similar formula.

  • Team performance over the past four seasons. The most recent year counts almost twice as much as the three years before it.
  • Returning starters at quarterback, as well as on offense overall and on defense. A starting quarterback is worth about 3.3 ppg to a team returning an average offense (all else equal), and a transfer QB is given half the weight of a starter.
  • Whether a team has a returning head coach. Ratings will regress slightly to the mean with the addition of a new coach.
  • Recruiting rankings (ESPN, Rivals, Scout and Phil Steele) over the past four seasons. ESPN describes this as a “very minor” component. 

All teams’ pre-season FPI ratings incorporate a predicted offensive, defensive and special teams value. Each unit is expected to contribute to the team’s net scoring margin on a neutral field against an average FBS opponent.

So I thought all these early pre-season team rankings were just for fun and giggles, or maybe just “click power”. As they say in so many areas of life, a little knowledge is dangerous.