Friday, October 9, 2020

Published 11:09 PM by with 0 comment

What Are the Most Common Scores in the NFL?

My guess going into this is that both teams score around 30, a field goal is the most common separation, and it's some combination of 7 and 3. Taking a guess then, I think 27 - 24 is going to be most common.
For the initial analysis, I'll take what I think is the most literal definition of 'most common score' which is what score is most common for a single team across all games. For data, I'm using the 2000-2019 NFL seasons. Doing that, I get the following plot:

So there's some obvious results here. No one ever scores only 1 point in the NFL because you can't. Scoring only 2 is super-rare since that means just getting a safety. Scoring 4 is even less common since that's only possible with 2 safeties. Getting into what's'd expect x*7 + y*3 to be most common since touchdown (td) + extra point is 7 and field goal (fg) is 3. Looking at the most common ones, the top 5 are:

  • 20 - can be done 2 common ways: 2 tds with extra points + 2 fgs, 3 tds with 1 missed extra point
  • 17 - 2 tds with extra points + 1 fg
  • 24 - 3 tds with extra points + 1 fg
  • 27 - can be done 2 common ways: 3 tds with extra points + 2 fgs, 4 tds with 1 missed extra point
  • 10 - 1 td with extra point + 1 fg
Just scanning through, the oddest one to me is that 16 and 21 occur roughly as regularly. 16 is likely mostly 3 fgs + 1 td with extra point, but I would have guessed 21 (3 tds with extra points) was much more common.

For another definition of 'most common score', I'll do the most common scores factoring in both teams in a game. That is, the most common final scores for NFL games. Doing that:

Given the first plot, this shouldn't be surprising. The top 7 scores here include one of the top 5 scores from the previous plot. What is a bit surprising to me here is that 1-score games (difference less than 9) seem most common. Looking at that in more detail, here is the distribution of margin of victory for all games:

No surprises from what we know from above...3 point difference is most common, and 7 point is next most common. On the '1-score game' note from above, doing some quick math, I get that ~50% of all NFL games in this period were decided by 1 score only (8 points or less). that last plot, you can see that the values on the right are larger than on the left. Since the right here means 'home team wins', this means that the home team wins more often. Adding it up, it turns out that over this 20-year period, the home team won ~58% of the time. Further, simply averaging the scores over this period, the home team averages ~2.5 points more points per game than the away team. Summarizing that, you could say that the home field advantage in the NFL is roughly 2.5 points and leads to the home team winning ~58% of the time.

That's it. Let me know if you want to see anything else with this data set.



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