Football season is right around the corner, and to say that we are all excited would be an understatement. We are excited to finally watch beautiful touchdown throws, running backs making multiple defenders miss on a breakaway run, edge rushers traumatizing offensive linemen and quarterbacks spinning around the defense.
Sometimes, however, we get too excited about what we see on the football field after the long drought that is the NFL offseason. This often leads to strong takes that one might just come to regret.
My colleague George Chahrouri summarised it perfectly in a tweet, suggesting that the outcome in Week 1 often dramatically shifts the perception of a team.
Friendly reminder that exactly one week from now the Dallas Cowboys will be Super Bowl Champions and the Rams will be in the Trevor Lawrence sweepstakes
— George Chahrouri (@PFF_George) September 7, 2020
Our goal in this article is to study how predictive the performance of the first two weeks is compared to performance at later points in the season.
We've seen both ends of the spectrum in recent years. Last season, three teams had a change of fortune that was visible very early, as the Ravens offense, the 49ers defense and the Bears offense clearly displayed within the first two weeks that they might not be the same unit they were in 2018.
On the other hand, New England's offensive struggles weren't visible in the first two weeks. And in the years prior, the Jaguars and Raiders started 2-0 with impressive wins in 2018 and 2017, respectively, not foreshadowing the negative regression these two teams were about to go through.
As always, anecdotes serve only as interesting talking points, and we have to look into the data to get an answer. We start with an easy exercise and look at the three main indicators of a team's performance: Overall performance as measured by point differential, offensive performance as measured by EPA generated per play and defensive performance as measured by EPA allowed per play.