Brock Purdy is 12-3 as an NFL starter in the regular season. His passer rating over that year-plus stint is a league-leading 112.2. He is operating within the confines of Kyle Shanahan’s low risk, high reward offense and thriving.
Does that make him 2023’s best quarterback? The numbers say yes, even if watching his game tape fails to inspire the same confidence.
Purdy has been an upgrade over Jimmy Garoppolo in an offense meant to blunt the liabilities of a shaky downfield passers with motion, movement and a ton of open space to create massive gains after the catch. But when pressed to fit big throws into tight windows downfield, the second-year passer has struggled. His 24 deep throws rank 23rd most in the NFL, a number that looks better than it is given the rash of quarterback injuries that have shaken up starting lineups this fall.
All five of his interceptions this season came in a three-game losing streak that stands as the only blemishes on his team’s 2023 record. Four came on throws at least 13 yards beyond the lin of scrimmage, showcasing his struggles when asked to force the ball downfield in disadvantageous situations. Purdy is very good, but he’s not in the circle of trust just yet.
That doesn’t keep him from holding down the top spot in this week’s advanced stats QB rankings — by a wide margin, in fact.
Let’s talk about those stats. 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 32 primary quarterbacks — the ones who played at least 176 snaps in 11 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.
1
The very much disputed king
1. Brock Purdy, San Francisco 49ers: 0.211 EPA+CPOE composite
It’s worth noting Purdy only has one fourth quarter comeback under his belt as a pro. That came in 2022 against Josh McDaniels’ Las Vegas Raiders, who were starting Jarrett Stidham at quarterback that week. This isn’t a concern as long as the Niners’ defense keeps shoving opponents into lockers, but it’s worth monitoring.
2
An MVP race without a frontrunner
2. Josh Allen, Buffalo Bills: 0.163 EPA+CPOE composite
3. Dak Prescott, Dallas Cowboys: 0.162
4. Tua Tagovailoa, Miami Dolphins: 0.152
5. Jalen Hurts, Philadelphia Eagles: 0.149
Prescott has carved up underwhelming competition and struggled against good teams. Ditto for Tagovailoa. Allen’s game requires trading off moments of brilliance with backbreaking turnovers, which is wonderful to watch as long as you’re not a fan of the Bills or whomever is playing them that week. Hurts’ interception rate has more than doubled from last season, but he remains the engine behind the league’s best team so … tough to complain too much.
3
The numbers struggle to quantify drops and bad routes, ya'll.
6. Kirk Cousins, Minnesota Vikings: 0.134 EPA+CPOE composite
7. Patrick Mahomes, Kansas City Chiefs: 0.133
8. Russell Wilson, Denver Broncos: 0.122
9. Jared Goff, Detroit Lions: 0.118
10. Lamar Jackson, Baltimore Ravens: 0.115
11. CJ Stroud, Houston Texans: 0.115
12. Justin Herbert, Los Angeles Chargers: 0.114
I don’t like sandwiching Mahomes between Kirk Cousins and the Broncos’ version of Russell Wilson any more than you do. Jackson and Stroud have also been more valuable than their composite numbers suggest. And poor Justin Herbert keeps getting let down by a franchise that knows only torture for its quarterbacks.
4
Better, or worse, than expected but still fine
13. Baker Mayfield, Tampa Bay Buccaneers: 0.097 EPA+CPOE composite
14. Trevor Lawrence, Jacksonville Jaguars: 0.091
15. Sam Howell, Washington Commanders: 0.080
16. Geno Smith, Seattle Seahawks: 0.075
Howell has had to throw the ball a ton, which makes his league-leading 12 interceptions a little easier to swallow. His 2.7 percent interception rate isn’t even in the bottom 10 when it comes to 2023 starters. Lawrence has been up and down this season but does well when he’s got all his receivers at the ready; with Christian Kirk, Zay Jones and Calvin Ridley all available the Jaguars are 4-0. Smith has cooled off from last year’s eye-opening campaign; an injury to his throwing arm may keep him locked in among the average QBs for the rest of 2023.
5
Slightly trustable
17. Joe Burrow, Cincinnati Bengals: 0.069 EPA+CPOE composite
18. Jordan Love, Green Bay Packers: 0.063
19. Justin Fields, Chicago Bears: 0.060
20. Derek Carr, New Orleans Saints: 0.052
21. Deshaun Watson, Cleveland Browns: 0.052
22. Gardner Minshew, Indianapolis Colts: 0.046
23. Ryan Tannehill, Tennessee Titans: 0.041
Apparently this is where we stick all the guys who are done for the season; Burrow, Watson and Tannehill have each been replaced due to injury. Their replacements haven’t shined in comparison, though that’s really only an issue for Tannehill, who’ll be a free agent next spring. Love continues to be difficult to analyze, though his targeting downfield has improved as the season wears on. He got big contributions from his young targets in Week 11 to generate a confidence-boosting win.
6
Guys who've been replaced at various points in 2023
24. Joshua Dobbs, Minnesota Vikings: 0.038 EPA+CPOE composite
25. Desmond Ridder, Atlanta Falcons: 0.034
26. Matthew Stafford, Los Angeles Rams: 0.030
27. Jimmy Garoppolo, Las Vegas Raiders: 0.027
28. Daniel Jones, New York Giants: 0.026
OK, let’s talk about situations.
Dobbs’ composite as a Viking: 0.120 (would be ninth-best in the NFL)
Ridder backup Taylor Heinicke’s composite as a Falcon: 0.038
Stafford backup Brett Rypien’s composite as a Ram: -0.073
Rookie Aidan O’Connell’s composite after replacing Garoppolo: -0.001
Rookie Tommy DeVito’s composite after replacing Jones (and Tyrod Taylor): -0.006
Not great, and it only proves what an outlier Dobbs’ first three games in Minnesota have been.
7
Ew.
29. Bryce Young, Carolina Panthers: 0.017 EPA+CPOE composite
30. Mac Jones, New England Patriots: 0.015
31. Kenny Pickett, Pittsburgh Steelers: 0.005
Frank Reich’s decision to vacate, then regain, offensive playcalling duties have done little to help Young. Jones plays football like a box of pasta hitting the ground, scattering everywhere and leaving nothing but frustration behind. Pickett gets a new offensive coordinator following Matt Canada’s ousting. This will help in as much as there’s no way things could be worse.
8
Guys who were replaced by Tim Boyle
32. New York Jets: 0.001 EPA+CPOE composite
Boyle’s composite number is -0.072. He isn’t going to fix a damn thing in New York.
