When choosing fantasy players, do you want to choose players whose teams are balanced, or do you want them to be the sole focus of the offense? Do you want the team to be reliant on the offense or to have a good defense? On the one hand, being the focus of the offense means lots of volume to produce with. On the other, it means that defenses will be selling out to stop you. In today's post, we are going to look at how these team-level abilities (specifically, rushing, passing, and defense) relate to fantasy production at the other positions.
The Data
We will be using data collected from profootballreference.com for all the analysis here. Specifically, we will use the fantasy production in PPR leagues and compare it to the Expected Points Added from rushing and passing per team and the Defensive Simple Rating System per team as calculated by Pro Football Reference. These statistics are calculated on a season-long basis, and I will be combining all data from the last 6 years (since 2015).
Bad Defense, Good QB
One of the most common refrains you hear is that having a QB on a team with a bad defense is ideal. The QB's team will be down or in shootouts all the time and therefore the team will have to throw the ball constantly to keep up with their opponent. Makes sense intuitively, but is it true?
Quarterback fantasy performance relative to their team's defense. limited to the top 25 QBs in a given year. The line of best fit is shown with a shaded 95% confidence interval
Looking across the top 25 QBs and we see no relationship between the team's defensive rating and the QB's fantasy performance. Statistically, we can run a Pearson regression and confirm that there is no relationship (p = 0.86). So at first glance, it certainly does not seem like the team's defense matters. But let's be honest, you don't care how good Patrick Mahomes' defense is, he's a good enough QB that he will be good for fantasy football regardless. So maybe the defense only matters for the lesser QBs? maybe it is something that can push a QB from average to startable?
QB fantasy performance vs team defense for QBs who finished between 6 and 18 in their given year. The line of best fit shown with the shaded area being 95% confidence interval.
And again we see no relationship (p=0.43). The average QBs are spread all over the place relative to their team's defense. We can say therefore that the defensive ability of the team does not matter.
Ok but what about offensive tendencies?
Billing Department
Are Running Backs more valuable on bad passing offenses?
First twist, not only is it not better to be a running back on a bad pass offense but it's actually worse (p = 0.03). This makes sense on some level because the real goal in fantasy football is touchdowns. If the offense has a better passing offense, then it will likely score more points overall and therefore provide more touchdown opportunities for the running back. (Side note, that extreme outlier was Christian McCaffrey in 2019, so outliers do exist). Overall, you clearly want running backs on better offenses, regardless of whether those points are coming from passing or rushing.
What about the passing positions (QBs, WRs, and TEs)?
Interestingly, we can see that a QB really benefits from having a good rushing game (p < 0.01), WRs benefit a little (p = 0.05) while TEs don't benefit at all (p = 0.34). So again, the passing dependent positions actually generally benefit from a good running game. Same as before, better offenses are good at both, running keeps drives alive and sets up the play-action, passing can create explosive plays and set up the run. Each side of the offense benefits from the other.
Limitations
The main limitation here is that this looks at season-long totals, but I doubt that the conclusions will change much on a week-to-week basis. Another limitation is that there is no metric of the team makeup and philosophy. Think about the Christian McCaffrey outlier in 2019. The team's philosophy was simply to get him the ball so he benefited even though the offense wasn't great. The same may be true for players going forward, but if we are thinking about what is most likely, I wouldn't rely on the outliers.
Conclusions
To sum it up, look for good players on good teams, it is just that simple. Trying to get cute by taking a QB with a bad defense or a RB on a team that cant pass won't actually produce an advantage.
All code related to this post is available on my github
Questions? Comments? Let me know at ac@alexcates.com. Want to read more breakdowns like this? sign up for my newsletter. Finally, like what I do? Consider supporting me on buy me a coffee.
Comments