I've been musing over this comparison over the entire offseason, and finally sat down to pound out the analysis and numbers. There are two primary reasons I've been unable to stop thinking of this comparison, especially in light of the large amount of praise Stafford has received over the past year.

* Whiplash from the perception/discussion around Stafford from his Lions days, where he was universally seen as a good quarterback, with great physical tools and highlights, but definitively a tier below the super elite of Brady/Manning/Brees/Rodgers, and even the one after that of Ben/Rivers. QBs like Matt Ryan and Russell Wilson were consistently thought of as better in the NFC, and made 3 and 5 Pro Bowls respectively (not counting replacement picks) in the NFC while Stafford made 0 Pro Bowls in the same stretch against them (not counting replacement picks) in his entire 12 year stint with Detroit.

* Salty Niners fandom as Brock Purdy put together a 2023 season with the 6th highest ANY/A of all time (higher than 07 Brady, 18 Mahomes, 84 Marino (era diff), and 13 Manning) and 16th highest passer rating of all time. Only to get promptly brushed aside, from MVP convo to not even 2nd team AP, due to having an offensive genius (Shanahan), two offensive superstars (CMC and Kittle), and some great additional support (Deebo and BA performing admirably) despite a horrible OL from LG <-> RT, save superstar Trent Williams. Whereas Stafford's MVP season in a weak year was hailed as transcendant despite having an offensive genius (McVay), two offensive superstars (Puka and Davante), and a great role player in Kyren Williams, not to mention a much better, legitimately fantastic OL with standout Kevin Dotson and no holes to speak of.

So before I talk further, let's look at the numbers between these two incredible seasons.

Comprehensive Quarterback Statistics

Rank in parentheses for all seasons from 2020-2025, key for stat explanations below

Statistic	2023 Brock Purdy	2025 Matthew Stafford
ANY/A	9.0 (2nd)	8.3 (7th)
Passer Rating	113.0 (4th)	109.2 (8th)
Success %	54.7% (6th)	54.5 (9th)
PFF Grade	87.4 (31st)	92.0 (7th)
DVOA	42.5% (2nd)	33.8% (3rd)
Adjusted EPA/Play	.360 (2nd)	.252 (17th)

Advanced Contextual Statistics

Rank in parentheses for all seasons from 2020-2025, key for stat explanations below

Note: As these stats commonly focus on one specific aspect of play, unlike the comprehensive stats, it is expected for even the best QB seasons to not chart well in every stat here. It is meant instead to show where different QBs shined, and where their weaknesses/differences are.

Statistic	2023 Brock Purdy	2025 Matthew Stafford
Air Yards Per Attempt	8.2 (60th)	9.0 (16th)
YAC Per Catch	6.6 (4th)	4.8 (145th)
Drop %	2.1% (2nd)	4.8% (99th)
Bad Throw %	16.3% (95th)	18.1% (133rd)
On Target %	75.5% (107th)	73.6% (146th)
Pressure %	20.1% (113th)	18.5% (141st)
Big Time Throw %	5.5% (35th)	7.7% (2nd)
Turnover Worthy Play %	3.2% (88th)	3.3% (98th)
Pressure to Sack %	13.1% (15th)	12.1% (12th)
CPOE	5.4 (15th)	1.6 (69th)

Key:

!ANY/A - A stat introduced in the mid 2010s, meant to better measure passing efficiency than passer rating, and with a higher correlation to wins, by removing the cap-based approach of passer ratings calculation, and removing the completion % input, while adding in sacks and sack yards to its calculation. (yds - sack yds + (TD * 20) - (INT * 45)) / (pass att + sack)!<

!Passer Rating - The classic QB statistic, computed by taking completion %, Y/A, TD %, and INT %, putting them in their own weighted formulas capped by an upper and lower bound, and then combining them into one number.!<

!Success % - Percentage of a QB's dropbacks that resulted in at least 40% of yards to a new down on 1st down, 60% of yards to a new down on 2nd down, or conversion on 3rd or 4th down.!<

!PFF Grade - An aggregate grade given by the PFF staff by grading each play on a sliding scale of -2 to 2, and converting the total breakdown to a 0-100 scale, with some special sauce. Includes passing and scrambling plays.!<

!Bad Throw % - Percentage of poor throws (tracked by pro football reference) per pass attempt, excluding throwaways/spikes!<

!On Target % - Percentage of on target throws (tracked by pro football reference) per pass attempt, excluding throwaways/spikes!<

!Big Time Throw % - A pass with excellent ball location/timing, further down the field and/or in a tight window!<

!Turnover Worthy Play % - Play that has a high interception chance, or fumbled the ball!<

!DVOA - Defense-adjusted value over average, a measure of a player's efficiency by comparing success on every single play to a league average based on situation and opponent.!<

!Adjusted EPA/Play - Adjusted expected points added per QB play (passing and rushing), taking into account the likelihood to score from across the field and down/distance calculations. Will also take into account opponent and situation to adjust accordingly. More predictive than raw EPA/play.!<

!CPOE - Completion percentage over expectation, based on the difficulty of the throw that is being made (distance, field location, proximity of defenders), denotes how much better or worse the completion percentage of the QB was.!<

Findings

For the most part, the comprehensive stats mark Purdy's 2023 season as a top 5 season of the decade so far (a standard MVP/best QB in the league season), and Stafford's as a lock top 10 season (usually 2nd team AP, the MVP runner up). However, there are some important deviations to look at.

PFF grades Purdy as the 31st QB over this stretch, or essentially the #5 QB in the league on average. This is a sharp contrast to his statistical performance, and there are two factors I'd present as likely influencers.

* Purdy at this point was playing his 1st full season. Scouts/graders, when faced with a "borderline throw" between good/great, or ok/bad, will subconsciously give more grace to veteran QBs they trust, then new rookies who haven't earned that yet.

* As will be addressed below, a lot of the 2023 SF offense relied on getting the ball out faster, using the middle of the field, and unlocking YAC opportunities. These throws, while correct and necessary, and done well if they lead the receiver and enable YAC opportunities, wouldn't grade as well as a deep bomb, or a placement throw for a jump ball catch as opposed to hitting the receiver in stride.

Still, is something to consider for Stafford's case. For him on the other hand, adjusted epa/play really found him to be far apart from the best seasons of the decade. Although similar to DVOA, which Stafford was fine in, EPA/play takes into account non-passing plays that Stafford makes, and may use slightly different formulas. As the 17th QB here of the last 6 years, this would be a typical QB3, almost as bad as Purdy's PFF rank.

The context stats do underline in the beginning how much the SF offense was based on YAC by the receivers. Their dominance there, and the low drop rate, helped make the offense as prolific as it was. However, if that's what the SF offense works better in (Deebo is better in space, not high pointing balls, ditto for the others), then that's what Brock should focus on, and the timing and accuracy skill set is still extremely valuable and more difficult in it's own right than a more traditional passing scheme. And Brock shows he has the advantage there, with more on target throws. He also faced more pressure, and as a result had to either get the ball out early, or scramble drill. Also his air yards per attempt, projected at ~#10 for a standard season, show that he was still passing the ball further than average, not just dink/dunking. He was a master of the mid game.

In a similar vein, Purdy had less big time throws, but he absolutely dominated Stafford in CPOE. This adjusts for their distance thrown, so Purdy overall was more accurate and completed more passes than Stafford, not just because he was throwing shorter.

And in terms of supporting cast: Puka is a better receiver than Kittle, Davante is a better receiver than BA. However, CMC is better than Kyren + Corum, and 2023 Deebo is still better than any 3rd option on the Rams. They both have two of the top offensive minds in the league. Rams have a better OL, and better top end options, so I'd say their supporting cast is better, though its close.

Overall

Stafford definitely played a more exciting, big play style of football, and executed it well enough to win MVP. But Purdy's more short->mid attack while not as exciting, still turned into a more efficient passing offense, with a similar or worse offensive cast. Most comprehensive sources have Purdy's season ahead in overall comprehensive metrics.

Furthermore, over the past 4 years since Brock entered the league, during which Stafford has enjoyed the better supporting cast without a doubt due to the injuries for the Niners, these are their stats.

Statistic	Brock Purdy (22-25)	Matthew Stafford (22-25)
ANY/A	7.8 (1st)	6.9 (8th)
Passer Rating	104.0 (2nd)	97.2 (11th)
Success %	52.4% (1st)	50.6% (4th)
PFF Grade Average	83.3 (6th)	80.5 (9th)
DVOA	42.5% (2nd)	33.8% (3rd)
Adjusted EPA/Play	.360 (2nd)	.252 (17th)

What is the timing bias here? There's a few at play. The career timing. Purdy puts up his best season when everything's clicking when he's in his first season ever as Mr. Irrelevant. What would blow him up more now, was thought of more as a "fluke"/"game-management only" at the time by many.

The MVP timing. If Stafford had put up this season in 2024 against Josh/Lamar, or 2020 against Rodgers, or 2022 against Mahomes, he probably wouldn't have won MVP, and wouldn't be getting this level of recognition.

If Purdy had gotten MVP in 2023, then maybe voters don't get "fatigue" and properly give Lamar the MVP in 2024. Now in a league with no Josh Allen MVP, Purdy with an MVP, maybe comparisons with him and someone like Stafford are much clearer.

All in all, its nothing shocking, the NFL and we as it fans are always biased by the timing of years colliding (Brees unfortunately having no MVPs). But it's fun to look past it and compare years like this.

I find it hard pressed to find an angle that doesn't put Purdy's 2023 season at the least right next to Stafford's 2025 if not better. Given that both of them have one of these MVP caliber seasons, and other good top 5-10 seasons around them, it seems that while you can place Allen/Mahomes/Burrow/Lamar in their own tier, Stafford, along with Maye and Purdy sit comfortably in that second tier (with your argument of Dak, Love, Herbert, Hurts, Goff either in that tier or slightly behind).

Hope this was at least an enjoyable read, happy to discuss or argue any of the above. Can't wait for this season to finally start!