Home Field and Scoring in the NFL, an Update

After four weeks, I noticed (well, everyone noticed) that scoring was increased in the NFL. In addition, the home field advantage didn’t appear to be what it used to be.

We’re now 105 games into the 256-game season. I wanted to apply some basic statistical concepts to the observations.

After week seven, home teams are 53-51-1 (50.9%). The historic winning percentage for home teams is 57.4%. If we assume that home teams win 57.4% of their games, what we’ve observed would give us about a 91% probability that we’re looking at a different home win expectation. That’s a complicated concept. What it means is that given 105 games at a 50.9% winning percentage, there’s a 91% likelihood that the 105-game sample came from a football world where we can no longer assume home teams win 57.4% of the time.

That’s not a very high threshold, and I’d say it’s too early to make that conclusion even though it looks like playing in empty stadiums is removing the home-field advantage.

What about scoring, then? After seven weeks, teams are averaging 25.4 points per game. The league record, set in 2013, is 23.5. The assumption that the 105 games played so far could come from the same football world as 2013 has about a 0.2% likelihood. That’s well above the threshold statisticians would use to test that kind of question. We are very likely in a new world of offense here. Whether that’s empty stadiums, or new offensive innovations or defensive rust is impossible to determine right now.

Meanwhile, I had promised people another Front Office Football update by the end of October. Again, I apologize, but I am still waiting to hear information that would allow me to make the decision whether to proceed with FOF9. Development remains on hold and I continue to learn new techniques. We’ll try again next month. As we all know by now, I am really, really bad at adjusting to the obvious. I beat myself up all the time about it, but unfortunately, it’s just who I am.

Author: Jim Gindin

Founder and Lead Developer, Solecismic Software