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How Consistent are Explosive Plays?

| May 26th, 2020

The Bears produced the fewest explosive plays in the NFL last year, and given the importance of explosive plays to overall offensive output, that largely explains their status as one of the worst offenses in the NFL.

So I want to look at how consistent explosive plays are. We’ll start with a team-by-team basis, and then look at it on a player-by-player level in a follow-up article.


The Setup

I used Pro Football Reference’s Game Play Finder to track explosive runs (gained 15+ yards) and passes (gained 20+ yards) for each team season since 2014. I did this to have 5 years to compare season-over-season consistency (2014 vs. 2015, 2015 vs. 2016, etc.), giving a respectable sample size of 160 data points without going too far into the past, since the NFL is a constantly evolving league.


Results

I started by doing a simple comparison of explosive plays a team had in one year compared to explosive plays they gained the following year. As you can see in the chart below, there wasn’t much of a relationship.

As a reminder, correlation (R²) is a measure of how strong the relationship between two variables is. It ranges from 0-1, with 0 meaning there is no relationship whatsoever. So a value of 0.027 tells us there is basically no relationship between how many explosive plays a team has in one year compared to how many they will have the following year.

I’ll note I did similar looks for explosive runs and passes when separated out from each other and got similar results (R² < 0.07 for both). I also looked at all three in terms of explosive rate (explosive plays/total plays), and got similar results. I don’t feel the need to pepper this article with a bunch of similar graphs that show no results, but if you’re curious, the full data set and graphs can be seen here.

This then, would seem to suggest good things for the Bears. Just because they were unexplosive in 2019 does not mean the same will be true in 2020. 


Factors Favoring Consistency

While there might not be a strong overall consistency in explosive plays from one year to the next, I wondered if there might be certain factors that favor consistency. Two that immediately came to mind are head coach and quarterback. Having consistency at those positions helps keep the offensive approach the same year over year, which might lead to more consistency in explosive plays.

A quick glance at the data revealed some anecdotal evidence that this might be the case. There were 8 teams who finished with at least 77 explosive plays (>5 above average) for 3 straight years at some point between 2014-19. Seven of them had the same head coach and QB combo for all three seasons. The 8th was Kansas City, who had the same head coach but saw a QB change from Alex Smith to Patrick Mahomes.

The five most consistent teams from 2014-19 (those with the lowest standard deviation of explosive plays/year in that range) averaged only 1.2 coaches/team in that stretch, while the 5 least consistent teams averaged 2.6 coaches/team (the NFL average was 2.1 coaches/team). Generally, teams with more coaches were more inconsistent (had a higher standard deviation), as you can see in the table below.

You can see the same trend with quarterbacks in the table below. I measured QB consistency by counting the total number of players who threw at least 200 passes in a season for the team between 2014-19.

I should note, however, that having one coach or quarterback doesn’t mean you’re consistent. A standard deviation of 10 on a sample of 70-80 plays is still rather large, indicating a fairly high degree of inconsistency. To further examine the strength of these relationships, I looked at explosive plays from one year to the next for all instances from 2014-19 where the team had the same QB and head coach in both seasons. That graph can be seen below.

On a whole, there’s still basically no relationship between explosive plays from one year to the next, even when the  coach and QB don’t change. My interpretation of this overall lack of relationship, compared to the anecdotal evidence of QB/coach consistency leading to a bit more explosive consistency above, is that it only works if you have a good coach and QB. It’s not about keeping the same coach/QB pair, but instead finding a quality coach/QB and then keeping them together. To put it simply, the quality of coach and QB leads to the consistency. The 8 teams who had 3 or more straight seasons with at least 5 more explosive plays than average had the following coach/QB pairings:

Every person in that list except Alex Smith has been in a Super Bowl, and they’ve combined for five coach of the year awards and sevem MVPs. So I would argue this suggests getting a great coach and/or QB can lead to you being somewhat consistently more explosive than average, but getting a great coach and/or QB is really, really hard.


Wrapping It Up

No matter how you parse the data, there is basically no year-to-year carryover for explosive plays on offense. This is fantastic news for the Bears, who were the least explosive team in the NFL in 2019.

Adding anecdotal evidence to this idea, I looked at teams who were similarly unexplosive as Chicago was in 2019. The average NFL team produces roughly 71 explosive plays/season over the last 6 years, while the Bears had only 48. Looking at some of their peers:

  • Only 5 teams had fewer than 50 explosive plays in a year between 2014-18, and all 5 had at least 70 explosive plays (so were average or better) the following year.
  • If you want a bigger sample size, 15 teams between 2014-18 had 55 or fewer explosive plays in a season, and 13/15 had at least 70 explosive plays the following year.

Those samples are far from a concrete statistical study, but they align with the larger data set above to suggest that regression to the mean is likely for the Bears’ offense in 2020. More explosive plays are coming, and that should lead to more points being scored.

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