By: Ian Turner
Every NFL drive starts with a first down and ten. While third down conversions are much more crucial to overall offensive success, play calls on first downs impact how many yards a team has to gain on second or third down. Of course, there is no one "right" play call on first down. Both running and passing plays have benefits and drawbacks - and how the two are used together in offensive play calling are crucial to offensive success. Every team, from the 2007-2008 Patriots to the 2017-2018 Browns, have strengths and weaknesses. A team's ability to play into their strengths and address weaknesses can make all the difference. For this article, we will dive into how teams with strong or weak pass and run games play call on first down and which play call strategies are the most effective.
Passing and Running Skills vs. First Down Play Calling
To evaluate a team's passing and rushing abilities, I looked at the QBR (a comprehensive metric of quarterback performance) of the quarterback that made the most starts for the team in the 2021 season and the overall team's yards per carry. Of course, this is an oversimplification - as passing and running talent cannot be easily evaluated - but these two statistics can give us a glimpse into each type of play's effectiveness.
Below is a graph of all 32 NFL teams, with the x-axis being the average yards per carry, and the y-axis representing the average percentage of run plays on first down.
Then I did the same with QBR and how often a team passes on first down, with the axes being the averages of the two respective variables.
Observe that Passing% on 1st is inversely related to Running% on 1st, so if a team passes 54% of the time, then they run 46% of the time.
Categorizing Based on Play Calling and Offensive Skill
Based on these two graphs, I have divided all 32 teams into 8 categories:
Teams that under utilize the pass
Teams that run more than average on first down, but have below average yards per carry and an above average QBR.
Teams that under utilize the run
Teams that pass more than average on first down, but have a below average QBR with an above average yards per carry.
Teams that struggle to pass and run (but pass more)
Teams that are below average in yards per carry and QBR, but pass more than the average on first down.
Teams that struggle to pass and run (but run more)
Teams that are below average in yards per carry and QBR, but run more than average on first down.
Teams that are only good at passing
Teams that are above average in QBR and pass more on first down than the average.
Teams that are only good at running
Teams that are above average in yards per carry and run more on first down than the average.
Teams that are good at running and passing (but pass more)
Teams that are above average in both QBR and yards per carry, but pass more than average on first down.
Teams that are good at running and passing (but run more)
Teams that are above average in both QBR and yards per carry, but run more than average on first down.
I have labeled teams that are above the average at yards per carry as good running teams and teams that are below the average as bad running teams. Of course simply because a team has a low yards per carry or lower than average QBR does not mean that their running or passing game is bad per se, but it is at least a less than ideal option. In addition, being labeled as a team that passes more on first down doesn't necessarily mean they pass more than 50% of the time, but simply pass more on first down than the NFL average.
Analysis of Offensive Performance
After dividing these teams into these categories, I looked to compare their respective points per game and third down conversion percentage. The team categories have been grouped in a way to demonstrate the differences between teams that run more versus teams that pass more - given a certain skill set. For example, Under Utilized Pass and Only Good Pass are groups of teams that have a below average running game and an above average passing game. The difference between the two groups is that one group runs more and the other passes more.
As expected, the teams that have both good passing and running games score more than the teams that have poor passing and running games. However, for teams that have a poor running game and strong passing game, the teams that run more on first down, score more than the teams that use their passing game more on first down. Conversely, for teams that have a poor passing game and strong running game, teams that run more on first down do better than teams that throw more on first down. So, it is better to overuse a weak running game on first down than overuse a poor passing game. This makes some sense intuitively, as running the ball often helps open up the field for the passing attack, as the defensive linebackers have to honor the run threat more. In addition, passing the ball is much more risky than running the ball - as interceptions are more common than fumbles in the NFL - so running the ball is a safer, more reliable option.
Now, let's look at third down conversion percentage.
Based on this bar plot, as expected, teams with both good run and passing games do well on third down, whereas teams that have poor run and passing games struggle on third down. However, as with points per game, teams with a good passing game and bad running game have more success if they run more on first down. For the teams that have both a good run and pass game, both third down conversion percentage and points per game are higher for the teams that pass more. Now for teams that have bad run and passing games, it is not clear whether it is better to run or pass more on first down, as teams that run more score more, but convert less third downs.
Red Zone Offense
Similar to the process done earlier, I created two plots of QBR and Passing% in the red zone on first down and Yards Per Carry and Running% on first down in the red zone and then sorted the teams into respective groups.
Observe that the average run rate on first down in the red zone is much higher than the overall first down run rate - about 60% to 52%.
Now looking at how these subsets of teams do in the red zone (the opponent's 20 yard line to the opponent's end zone), we have this bar plot.
Based on this, teams with good quarterbacks and bad running games perform about the same regardless of first down usage. However, teams with good running games and bad passing games do better in the red zone when they utilize their running backs on first down. Similarly, teams with bad running and passing games do better when they run the ball more on first down in the red zone, and teams with good running and passing games do better when they throw the ball more in the red zone.
Based on Points Per Game, 3rd Down Conversion %, and Red Zone TD%, we were able to observe that based on a team's strength or weakness in the running or passing game, which strategy on first down performs better.
For teams with an above average quarterback, and a below average running game, the teams that ran more than average on first down performed better than the teams that threw more on first down. And for teams that have a good running game and a below average quarterback, those that ran the ball more on first down also performed better. So based on this, teams that struggle in either the run or the pass are better off favoring the run on first down. This pattern demonstrates that running the ball - effective or not - can open up the passing game and lead to an increase in scoring, third down conversions, and touchdown rate. While teams that run often may not have the flashiest of offenses, running more often on first down allows teams to open up the field for their passing attack.
For teams that have a poor running and passing game, teams that ran more on first down had a better scoring rate and red zone TD rate, but a worse third down conversion rate.
And finally, for teams with a strong running and passing game, teams that passed the ball more than average on first down found more success. So, for teams that are only good at running or passing, running seems to be preferable, but for teams that are good at running and passing, passing more on first down leads to more offensive success.
There is no one answer for what plays to run on first down. The way teams mix their run and passing game is far more important than the percentage that teams run on first down. But this gives an indication that for teams without all the weapons, running on first down may be a better option, and for teams with a strong passing and running attack, passing can lead to more success. But, football is much more complicated than choosing to either run or pass, and the patterns observed in this article are only tiny insights into a very complex sport. But these results are significant, and demonstrate how crucial running is in a team's offensive attack. However, because there are only thirty two data points, these eight subsets are fairly small, so outliers do have a fairly strong effect on each of the mean statistics, so it would be wise to collect more data from other seasons and check if the conclusions still hold.