What to make of Brock Purdy?

The 49ers QB is here, and won't be going anywhere anytime soon.

At the beginning of the season, we named Brock Purdy as a Tier 1 Quarterback, based on his performance in the games he had played up to that point. Purdy had put up stellar numbers the previous season as a rookie: going undefeated and averaging a 107 quarterback rating, amassing 17 touchdowns in just 7 games, with an 66% completion percentage.

But Purdy was unheralded coming out of college at Iowa State and did not have the physical traits that wow scouts. He was viewed as, at best, a backup for a west-coast offense that did not emphasize aggressive passing.

Fast forward to today and commentators in the media are still reluctant to accept Purdy as a NFL-ready quarterback, preferring physically impressive, but inconsistent players such as Lamar Jackson, Jalen Hurts, and Josh Allen. Or the, even the decidedly average: Dak Pescott.

But some are starting to come around, admitting that Brock Purdy is good. The question then, of course, becomes how good? What should we expect?

We attempt to answer that question, by looking at all the quarterbacks who, before 27 years old, put up a 9-game stretch comparable to the first 9-games of Purdy’s career: more than 250 pass attempts, and a 105 or better quarterback rating.

In total, there were 25 such players, including some all-time greats: Drew Brees, Aaron Rodgers, Brett Favre; and some less-than greats: Nick Foles, Chad Pennington, and Marcus Mariota.

By games started, the top 5 among the group all started more than 220 games in their careers, or about 13 full seasons of NFL games. Those who are started in the fewest games were all Purdy’s contemporaries—up and coming quarterbacks who will likely be in the league for another 5 years at least. Among those whose starting quarterback days are behind them, the averaged 76 games: or about 4.5 seasons of play.

We also took a look at career passer rating, to see about how successful we might consider Purdy to be over his career. The top-five in this category include Super Bowl winners Patrick Mahomes, Aaron Rodgers—who joined Purdy in our P(100) Tier 1 this year—and Russell Wilson, along with Deshaun Watson and Joe Burrow. The five worst were Nick Foles (Super Bowl winner), Brett Favre (3x MVP, Super Bowl winner, and Hall of Famer), Cam Newton (MVP), Joe Flacco (Super Bowl winner), and Brian Griese. Here, you’ll note that even the low-end comps have significant accolades.

Career Expectations

Using the 25 players with a similar 9-game stretch before the age of 27, can give us a rough distribution of outcomes for Purdy. If Purdy goes right down the middle of these 25 players, we should expect him to start 141 games—about 8 seasons—and average a 94 passer rating. That would place him somewhere between Jared Goff and Ben Roethlisberger. Which would be to say, no one would confuse him with an all-time great, but you would feel comfortable with him at the helm.

If he underperforms—and is better than only 25th percent of his comps—we would expect Purdy to start just under 50 games and average a 92 passer rating. This would make him most similar to Nick Foles, Super Bowl 52 MVP and champion. And this would play nicely with the critics take on Purdy: a limited system quarterback shines brightly for a few years while surrounded by top talent, winning the Super Bowl while playing some of his best football, but ultimately spends the back-half of his career as a backup.

Lastly, if Purdy surprises and performs better than expected—at the 75th percentile of performance versus his comps—he would average a 98 passer rating over 245 starts, or 15 seasons. This would correspond to a career much like Drew Brees, another undersized, weak-armed, quarterback. Drew Brees of course, briefly held many of the career passing records, until Tom Brady acquired them all via his incredible longevity.

In a few weeks, we’ll revise our P(100) rankings based on data from the current season, and take a look at how the other young QBs are faring. But it doesn’t look like Purdy is going anywhere anytime soon.

Brock Purdy is going to be with us for at least a few years. And so long as he is with Kyle Shanahan and the talented 49ers team, we should expect him to impress.