Does the Preseason Matter? Quarterback Edition

Digging through the (sparse & noisy) data and finding some signal for what the preseason can tell us about rookie and second-year quarterback play

CJ Stroud had a nightmarish start to the preseason: Does it 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 quarterbacks, specifically rookie and second-year players. After two years in the NFL, you’re not likely to learn a ton from preseason play.

Any quarterback with a real shot at NFL success should have built up a much larger sample of play to judge from the previous two regular seasons. Let’s not spend our precious time looking for quarterbacks to go from the bench to third-year breakouts. Plus, quarterbacks notably struggle as rookie, but, in the vast majority of cases, make the leap in their second seasons, if they’re going to break out at all. Yes, Josh Allen exists as evidence of a third-year leap, but we’re not going to have a ton of data for others to sift through (Allen, himself, doesn’t have third-year preseason data with its cancellation in 2020).

For preseason data, I pulled numbers from PFF, including grading and passing efficiency in the form of yards per attempt and adjusted net yards per attempt, which seeks to incorporate the value of touchdowns, interceptions and sacks on top of the baseline efficiency of YPA. For regular season performance, we have the same PFF grading measures, plus expected points added (EPA), the best advanced metric for quantifying play-by-play value.

Spoiler alert: there’s actually hints of a link for preseason and regular season performance, especially for rookie quarterbacks. Splitting the preseason data by pressure also shows benefits, as it did when I looked at college data from quarterback prospects.

PRESSURE NUMBERS THE KEY TO PROJECTING QUARTERBACKS

Looking at the most simple correlations of preseason play, we see that anything from poor to average PFF pass grading for rookie quarterbacks in the preseason doesn’t have much signal for how those quarterbacks will grade in the regular season (minimum 100 regular season dropbacks). But there is a strong correlation with the best preseason performers, who have generally gone on to grade well during the regular season.