There was a curious trend for the San Francisco 49ers’ offense through the first five weeks of the 2024 season.
After leaning heavily on play-action through Brock Purdy’s first season-plus, they started going away from it this year. It would’ve made sense had Purdy’s numbers out of play action started dipping, but he was still seeing a massive uptick in productivity on those plays.
In 2022 the 49ers ran play action 26.6 percent of the time with Purdy under center. That number dipped a little to 23.0 percent last year in his first full season as a starter.
Going into Week 6 of this season, the play action rate had plummeted to 17.6 percent.
It was a head-scratching choice that head coach Kyle Shanahan explained in a press conference Wednesday.
“No, we just try to run what we think looks good on tape and it kind of just depends on how people are playing us and sometimes we think it looks really good, sometimes we think it’s not so good,” Shanahan said. “So it’s not like we don’t just do things every week because we do it. I think it’s just been just a matter of how the schedule’s played out.”
We dug into some of the 49ers’ play action numbers and it was pretty easy to spot what got the team’s play action rate down. It turns out blitzing San Francisco heavily this season will typically get them out of their play action game.
Here’s a handy graph we made using data from Pro Football Focus:
The 49ers’ play-action rate against the Vikings was just 6.7 percent thanks to Minnesota blitzing Purdy on 51.1 percent of his dropbacks.
Against the Patriots’ 40.0 percent blitz rate, San Francisco ran play action just 13.3 percent of the time.
Conversely, the 49ers’ season-high 29.0 percent play action rate against the Seahawks came with Seattle blitzing on a season-low 19.4 percent of the 49ers’ dropbacks.
The only real outlier from this trend is Week 5 where the Cardinals brought a blitz on 46.3 percent of Purdy’s dropbacks and the 49ers still passed with play action 24.4 percent of the time. Interestingly, that Week 5 performance was also Purdy’s worst of the year. He completed just 54.3 percent of his throws and tossed two interceptions with only one touchdown for a season-low 62.1 quarterback rating.
This all tracks with what Shanahan told reporters in response to questions about the team’s drop in play action rate. Defenses that blitz more are generally going to keep the 49ers from running longer-developing plays that require a fake handoff.
Eliminating the Patriots and Vikings games puts the 49ers’ play action rate at 24.4 percent – right between what it was in Purdy’s first two years.
Play action hasn’t been abandoned by the 49ers. Defenses are just playing them a little differently in 2024. That’ll always be an important element to the 49ers’ passing game, particularly given how effective their run game is. However, how Purdy adjusts against the blitz and how the offense adapts to punish teams for bringing extra pass rushers will ultimately determine their success on that side of the ball this season.
