Thursday, September 6, 2018

2018-19 NFL Week 1 Power Ratings

It's that time of the year again - the NFL is back!

With the 2018 regular season set to begin tonight, it's time to discuss Week 1 power ratings.

As a reminder, I do not put any weight into W/L records when constructing these ratings. Mainstream outlets like ESPN and Bleacher Report basically just rank every team in order according to win/loss record and are heavily influenced by what happened the previous week. I'm pretty sure my eleven-year-old cousin is capable of ranking teams in order (1-32) based on win percentage.

I prefer to take a big picture approach considering I understand you can't overreact to a single game of football - the ball isn't even round! I also realize every team plays a different strength of schedule, and thus raw W/L records don't really tell us much about how good a team is compared to another.

Numerical values are assigned to each team in order to get a better estimation of how much better one is than another. New England is the best team in the NFL according to my ratings, but how much better are they than teams like Pittsburgh, Dallas and Chicago? I look to answer those types of questions when constructing power ratings.

The primary components used to generate these numbers are:
  • Yards-per-play differential from the prior year
  • Season over/under win totals blended with strength of schedule projections
  • Week 1 market expectation

Power ratings are generally used to project the beginning stages of a point spread.

For example, if Minnesota played Carolina on a neutral field, my ratings suggest Minnesota would be about a 3.5-point favorite. Other elements such as location, perception, schedule spots, etc. are then factored into the number to create a more accurate point spread.