He should be hitting wide open guys but to me his success is more a credit to Kyle Shanahan and his roster than him somehow being a savant.
I do not think he is that much, 10 points, better than Jimmy G on offense. Let's also look at the defensive points per drive rank of who the 49ers have played starting with Miami:
Miami: 2.17, 27th
Tampa: 1.86, 12th
Seattle: 2.11, 22nd
Washington: 1.72, 6th
Vegas: 2.34, 30th
Arizona: 2.39, 31st
Seattle: 2.11, 22nd.
We're talking 7 games and 5 of those are against bottom 10 defenses.
With EPA per play we can measure their expected point differences and multiply that by the average number of plays and it is 0.240 per play for Jimmy G vs 0.269 for Purdy. So 0.029 points per play better. Over the course of a 70 snap game Purdy is around 2 points better than Jimmy G.
He is middle of the pack throwing deep, 11.5% of the time and that's an upgrade over Jimmy G for sure who is always at the shallow end of that swimming pool.
I suppose for me it's more when I watch the 49ers I see a good offensive line and then basically pro-bowler caliber talent at skill positions combined with a fantastic coach. I was marveling at Kyle Shanahan and not Purdy when I saw them take apart the Seahawks. I would argue there are two coaches right now, in 2022/2023//this-season, who excel at putting defenders in conflict, Kyle Shanahan and Andy Reid.
Next-gen stats (NFL.com):
Aggressiveness tracks the amount of passing attempts a quarterback makes that are into tight coverage, where there is a defender within 1 yard or less of the receiver at the time of completion or incompletion. AGG is shown as a % of attempts into tight windows over all passing attempts.
Brock Purdy has the 2nd lowest rate of aggressiveness in the NFL. He is throwing to wide open targets which is all part of Shanahan's plan. He has the 4th lowest longest completed air distance one behind Jimmy G because neither guy has a cannon and this isn't that kind of offense. He and Jimmy G are bottom 10 guys for average air yards to the sticks. Why? Again it's the scheme. They throw to an open guy, often short of the sticks, who then RACs the other team to death. Guess who has the highest and second highest expected completion % in the NFL? Jimmy G and Purdy! It's the system. I admire the hell out of Kyle Shanahan. I think the guy is brilliant. I put him, McVay, and Andy Reid on a pedestal. I'm not sure how good a QB Purdy is because his situation from the teams he has played, to his surrounding talent, and to his coaching has been perfect or darn near close to it. I think we as fans tend to distill offenses and offensive success to the QB. I want to push back hard against that especially here and in these circumstances.
Shanahan imo deserves coach of the year consideration.