Yes, Brock Purdy landed in the perfect spot for a flawed-but-accurate quarterback. The San Francisco 49ers have long cried out for a passer who can make the right reads and escape the baffling decisions and occasionally awful throws of the Jimmy Garoppolo era — an era that resulted in three trips to the NFC title game or beyond in the last four years, by the way.
That need resulted in an offense that creates swaths of wide open space and trusts its playmakers to capitalize on it. The 49ers have led the league in yards after the catch in five of the last six seasons, including in 2023. This year, they’re profiting from a full campaign from Christian McCaffrey, who is on pace to be just the sixth player in NFL history to score 25 total touchdowns.
The man in the middle is Purdy, who is recording one of the most efficient seasons of quarterbacking in NFL history. His 119.0 passer rating would rank fifth-best all time. His 0.405 adjusted expected points added (EPA) per play is higher than Patrick Mahomes’ in either his 2022 MVP season (0.305) or 2018 MVP season (0.380). He leads the league in touchdown passes, touchdown rate, yards per attempt, adjusted yards per attempt and, well, just about any efficiency statistic you can measure.
That’s why he’s at the top of this week’s quarterback rankings once more — and why the gulf between him and the next closest competitor has widened. Purdy threw four touchdown passes in a sterling performance against the overmatched Arizona Cardinals. Dak Prescott, his closest competition when it came to both advanced stats and MVP odds coming into Week 15, sputtered in a blowout loss to the Buffalo Bills.
So where’s that leave Prescott, aside from “behind Brock Purdy?” Let’s crunch some numbers.
Expected points added (EPA) is a concept that’s been around since 1970. It’s effectively a comparison between what an average quarterback could be expected to do on a certain down and what he actually did — and how it increased his team’s chances of scoring. The model we use comes from The Athletic’s Ben Baldwin and his RBSDM.com website, which is both wildly useful AND includes adjusted EPA, which accounts for defensive strength. It considers the impact of penalties and does not negatively impact passers for fumbles after a completion.
The other piece of the puzzle is completion percentage over expected (CPOE), which is pretty much what it sounds like. It’s a comparison of all the completions a quarterback would be expected to make versus the ones he actually did. Like EPA, it can veer into the negatives and higher is better. So if you chart all 31 primary quarterbacks — the ones who played at least 240 snaps in 15 weeks — you get a chart that looks like this:
Top right hand corner is good. Bottom left corner is bad. Try splitting those passers visually into tiers and you get an imperfect eight-layer system that looks like this:
These rankings are sorted by a composite of adjusted EPA and CPOE to better understand who has brought the most — and the least — value to their teams across the small sample size. It’s not a full exploration of a player’s value, but it’s a viable starting point. Let’s take a closer look.