Does the Preseason Matter? Running Back Edition

There's plenty of signal in preseason rookie running back performance, if you know which stats matter

The preseason is into full swing with a full slate of matchups last week, and another couple on the horizon. The preseason has lost some importance over the last few years, with the 2020 season going off without a hitch despite no preseason, the shift from four to three games beginning in 2021, and a growing number of teams moving away from playing key starters at all. Still, we should see a lot from younger, unestablished players over in August, the players with the most uncertainty in their forward-looking projections.

Before we make too much from what we see this preseason, we need to look back at the past to see if there has been any signal in what we see in the preseason translating to the contests that count during the regular and postseason. This analysis is going to focus on running backs, specifically rookie and second-year players. After two years in the NFL, you’re not likely to learn a ton from preseason play. Previously, I looked at the significance of preseason play for early career quarterbacks, and found some insights to apply to the 2023 class.

For preseason data, I pulled numbers from PFF, including traditional volume (attempts) and efficiency stats (yards per carry), plus their charting metrics, like run grades, broken tackles, elusive rating, breakaway runs and yards after contact. I’m going to compare running backs’ preseason performances using those stats to their rookie-year rushing attempts over expectation, based on their draft position. What we’re primary interested in, especially in the fantasy football realm, is who will see volume during the season, so that’s what I’m focused on.

Spoiler alert: there are some strong correlation between certain preseason stats and volume over expectation in the regular season, but also a few types of measures that can fool observers into thinking a superficially strong preseason will translate.

VISUALIZING THE PRESEASON METRICS

No need for a long preamble here: Let get right into the numbers. In the plots below, I contrast different preseason efficiency metrics (2013-2022) on the X axis with rookie-year attempts over expectation on the Y axis. First, I’ll show exactly how strong the relationship between draft position and rookie-year attempts is, the basis for calculating the above/below expectation numbers. The sample includes running backs with a minimum of 10 rookie-year rushing attempts. I gave UDFA’s a draft position of 300.

How far each rookie rusher falls above or below the trend-line above is the figure I’m using for over/under expectation. I figure it’s a lot more valuable to look at this number than draft agnostic attempts.

First, let’s look at simple volume, comparing preseason rushing attempts per game to regular season rushing volume over expectation. The top-20 rookie running backs during the sample period (2013-2022) are highlighted and labeled.

There isn’t much to gain looking purely at volume in the preseason, which makes sense as likely starters play, perhaps, a few drives and then leave the majority of usage to players on the bubble, fighting for roster spots. None of the top-20 rookies in volume over expectation had more than 10 attempts per game in the preseason.