The Brock Purdy story has been fantastic to follow. A late-arriving entrant into the Offensive Rookie of the Year race, Purdy will likely win the award despite playing half the season. His explosive entry onto the scene has been made all the more unbelievable given his position on the roster and position in the draft.
The San Francisco 49ers Offense Is Perfectly Designed for Brock Purdy
It’s well known now that Purdy was the final player selected in the 2022 draft, earning the title of “Mr. Irrelevant,” given the low impact of players selected there. Even more surprising is that Purdy made the roster at quarterback above Lions quarterback Nate Sudfeld, who was given a guaranteed contract that offseason to be Trey Lance’s backup.
Despite Purdy only earning one or two reps early on in camp as the third arm — Jimmy Garoppolo sat out while the San Francisco 49ers attempted to trade him — the small windows into his talent were enticing enough to encourage head coach Kyle Shanahan to keep Purdy above Sudfeld.
As Shanahan said, “Every time [Purdy] got his one or two reps in practice, just how decisive he was and got the ball to the right spot and did it aggressively. Never seemed unsure of anything and so he kept earning more reps, and the more reps we gave him, the more he continued to look the same and didn’t take any steps back.
“Then he carried it over to some of the preseason games,” added Shanahan. “So by the end of that, it was pretty easy to see how Brock was coming, and we knew we wanted to keep him on the roster and not risk him going to practice squad, so it was a decision we had to make.”
The problem is that the Purdy we’re seeing in the postseason is not the one that Shanahan signed onto the roster, and it’s not just because of the normal process of rookie development.
There have been two Brock Purdys.
The one in the regular season who was getting rid of the ball on time within the structure of the offense and relying on his after-catch receivers and the one in the playoffs that has been a no-holds-barred scrambler willing to throw deep. If either of them shows up, it could be a big problem for the 49ers.
The Shanahan playbook is both small and large. The number of plays that Purdy is being asked to run is relatively small compared to the inventory of plays around the NFL, but that’s not a knock on Purdy.
The two best quarterbacks of the 2000s, Tom Brady and Peyton Manning, had completely opposite approaches. Brady would have a large array of plays at his disposal, sometimes going entire games without calling the same passing play twice. Manning would sometimes enter games with a play count smaller than his jersey number.
These approaches had different advantages and disadvantages. Manning needed to make sure that everyone on the offense was highly-tuned and executing at a high level. The advantage is that the Colts knew those plays better than anyone else.
Defenses would encounter those plays only one week of the year, while the Colts would run them all 17 weeks. In order for that advantage to mean anything, they would have to execute them inch-perfect. Defenses knew what was coming, so Indianapolis simply had to be better than their opponents.
The Brady playbook was notoriously difficult for receivers to learn, and New England had a difficult time finding receivers in the draft and free agency that had the bandwidth to learn the playbook every week and combine the various option routes, route concepts, hot reads, and audibles in it along with Brady’s preferences for how to attack each coverage given the route pattern on each side of the ball.
But with answers to every test defenses could throw at them, it was hard to stop.
In this instance, is Purdy out-executing opposing defenses with precise timing, technique, pre-snap diagnosis, and accuracy? Not really. He’s been fantastic, but his approach has been very rough around the edges.
That makes sense for a rookie regardless of where he was selected in the draft, but especially one from Matt Campbell’s offense at Iowa State — one that emphasized RPO concepts in a spread-heavy offense that made reads remarkably easy for the quarterback but limited opportunities to adjust plays or read the full field.
That doesn’t mean it was easy to pick up the playbook. But it was relatively easier than some of the more voluminous playbooks around the NFL. And making it simple for the offense doesn’t mean making it simple for the defense.
Shanahan’s approach has been described by a number of his disciples as “the illusion of complexity,” where things look complex to opposing defenses but, in reality, are quite simple. And the 49ers have more tools in their toolbox to muddy up the view for those defenses.
With players like Kyle Juszczyk, George Kittle, Deebo Samuel, Christian McCaffrey, and Brandon Aiyuk, the 49ers have the ability to move pieces around more than any other team in the NFL. Samuel can play running back and has been an excellent chipper on the line of scrimmage as a “tight end,” while also lead blocking well for Aiyuk on his big plays.
McCaffrey can run any route in the receiver route tree from any position on the field, whether that’s in line, in the slot, or on the outside. Juszczyk and Kittle trade off positions constantly at fullback, wingback, and tight end. Kittle also has the ability to run receiver routes on the outside.
This ability to move players around can dizzy defenses, especially when paired with truly positionless football that allows the team to run the same play out of dozens of formations, making it easy for the quarterback — whose reads are the same — but difficult for the defense.
That’s why Shanahan’s receivers are more open than almost any other group in the NFL. Purdy, according to NFL’s Next Gen Stats, threw the second-fewest percentage of his attempts to receivers within a yard of the defender.
It also explains his relatively short targets. Next Gen Stats records him as having the third-shortest depth of target from the line of scrimmage and fourth-shortest depth of target when measured against the first-down marker.
No offense in the NFL is more dependent on after-catch production than the 49ers’, with and without Purdy.
He knows it, too. After his win against Arizona in Week 18, he said, “I’ve got so many playmakers around me I don’t feel I have all the weight of the world on my shoulders to make something up.”
“[Shanahan] calls a great game plan,” said Purdy. “I just go through my progression, throw checkdowns to guys like Christian [McCaffrey] and Deebo [Samuel], and they make guys miss. I’ve just got to distribute it to guys, and they come up with all the yards.”
In an entirely different offense than the one he ran in college, Purdy plays with a similar style. Of all FBS quarterbacks with at least 300 attempts in 2021, he had the third-shortest depth of target.
Playoff Purdy Is College Purdy
There is one element of play that runs counter to the style he’s demonstrating right now — a long time to throw and a tendency to scramble. His average dropback took three seconds, 15th longest among FBS quarterbacks in 2021.
Purdy’s time to throw is down in the NFL, and in the regular season, it matches the league average of 2.73 seconds. It’s not quite as systematic as Garoppolo, a quarterback with a snap-and-throw process that saw him get rid of the ball faster than almost anyone else in the NFL, but it’s much faster than his college tendency.
The issue is that Purdy naturally wants to make plays. He doesn’t have the arm strength of many of the league’s best scrambling playmakers, which means his throws demand more precision.
As the weeks have gone on, he’s become more audacious with his playmaking. In his two postseason games, Purdy’s average time to throw jumped up to 3.21 seconds from his 2.73-second regular-season average.
While this has led to some of his best moments with some incredible throws, it also put him in trouble. In the first half of both of his postseason games, Purdy struggled. He made some dangerous throws and threw further downfield than he had during the regular season without much success.
After the Seattle game, Shanahan was asked about Purdy’s college free-wheeling tendencies and how well he’s tamped that down in the NFL. “I think he’s done a real good job,” said Shanahan. “He’s extended a number of plays. I think he’s made a few mistakes. There’s a fine line between all of that, but when there’s no play there, you always want guys to extend plays.”
He added, “I think guys get in trouble when they start relying on extending plays before making the play that’s there. I think that’s sometimes things you have to be careful of, especially when you have some playmaking ability like that. And I think that’s stuff that Brock has learned, and he’s done a pretty good job of. There were a couple of times he extended the play last week where he almost got in trouble, and he was able to survive it.”
Against the Raiders, Purdy had a fourth-quarter opportunity to Tyler Kroft, the intended read on the play, for a touchdown. He threw it to a covered Aiyuk instead. A better decision could have avoided overtime.
“I would say the one to Kroft, yes, I rolled out I was trying to hold the defender with my eyes and then come back to hit B.A. on that shallow,” said Purdy after the game. “Obviously, Kroft was there. In the moment, I was just trying to make a play to B.A., but right as I threw it, I look back, and I see Kroft, and I’m like, man, I already know that’s going to be one of the plays and it was.”
This theme came up again after his Seahawks performance. Shanahan said of Purdy’s spotty first half, “Yeah, there were a couple of open guys that he just missed.”
But later, Shanahan added, “When you just have a couple misses, you really don’t want to panic. Brock’s an accurate thrower, he has been doing that all year and playing well. He missed a few, and I don’t think there was really much of an explanation for it. We had to settle down a little bit and give him a few more opportunities, and he got those in the second half and was pretty lethal with them.”
Some of the best throws in the playoffs — from any quarterback, not just Purdy — have come off these scrambles. The deep shot to Kittle that took a few friendly bobbles to reel in was off-schedule; Kittle wasn’t in the progression. So too with his touchdown in the red zone to Elijah Mitchell in the fourth quarter against Seattle.
Purdy Will Have To Find Balance To Beat the Eagles
Against the Eagles, he’ll have to combine those tendencies. Philadelphia invites short passes perhaps better than any other defense in the league and feast on turnover production on the few deep throws they see. On top of that, they have the second-best pressure rate in the league and convert pressures into sacks better than any other team in the NFL.
All of that is to say that Purdy likely won’t be able to play a completely free-wheeling form of football with all the pressure bearing down on him and needs to be careful with how he improvises or throws deep. But he can’t rely solely on a short, methodical passing game.
On passes longer than 2.75 seconds, the Eagles perform better than any other team in the league. They allow -2.95 expected points per passing dropback, by far the best rate in the NFL.
That’s a concern, and Purdy will need to be more diligent about picking his spots than he was against the Seahawks or Cowboys.
“What’s been cool about Brock when he does get surprised, he’s got the quickness to sometimes be able to get out of it,” said Shanahan after the Raiders game, where they needed overtime to pull out a win. “He did that and was able to save it not being a bad play, but you can’t always count on making that guy miss.”
Purdy’s scrambles have put him in enormous trouble, but he’s been able to dig out of it so far. But the reliability of that tactic is minimal. Against a better closing team like Philadelphia, he’ll have to play in structure more often.
The problem is that the Eagles also do a good job closing down on short throws and aren’t extraordinarily susceptible to yards after catch. If San Francisco relies exclusively on the short game, there won’t be much there in terms of scoring, even if they can be confident that they are somewhat consistent in their passing game.
So Purdy will need to combine his regular-season play with his postseason play if he’s ever going to have a chance of advancing to the Super Bowl and becoming the first rookie to start at quarterback in the game. In essence, the two Purdys will have to become one.
The further teams advance in the playoffs, the smaller their margin for error. And as Shanahan said of Purdy’s freelancing, there’s a fine line.