Brock Purdy has done nothing wrong. QB10, QB5, QB1 and QB9 in four weeks, 11 touchdown passes against one interception, and 122 rushing yards. The consensus has him QB9 for Sunday, and on form that looks low.
This call is not about form. It is about the setting. San Francisco is a 2.5-point underdog in Seattle, in a game with a 45.5 total, which puts the 49ers at an estimated 21.5 points. Seattle's defense finished DST2 last week.
Over 18 weeks of backtesting, 2025 from Week 4 plus 2026 so far, 31 quarterbacks sat inside the projected top 12 on a team expected to score 22 points or fewer. Twenty-one of them, 68%, finished outside the top 12. Among quarterbacks ranked ninth to 12th, where Purdy sits, it was 70% on low totals and 58% on totals of 25 or more.
Our model, which blends the projection with the Vegas total, has Purdy 12th this week, which is why he is a Sit and not a Must Start. A Sit is a claim he finishes outside QB12.
The honest objection is that he has beaten every setting so far, and four weeks of efficiency are real. But in our data the team total is the one quarterback Sit signal that still helps after accounting for where a player is ranked, and 21.5 is tied for the second-lowest of any quarterback in the consensus top 12 this week. If he throws three touchdowns in Seattle, this one will look bad.