How Brock Purdy short-circuited the Seahawks’ defense with deep throws

Kyle Shanahan knew the Seahawks would be sitting on short routes. Deep throws, even when they missed, discombobulated Seattle.

In the first playoff start of his career, rookie Brock Purdy — the 262nd and final pick of the 2022 NFL Draft — came out firing. And, more often than not, missing.

After thriving in the short-target, big gain offense upon which the San Francisco 49ers have long relied to prop up Jimmy Garoppolo, Purdy tried to blow up the Seattle Seahawks on the opening drive of his Wild Card debut. During the regular season, a stretch in which the former third-string QB went 5-0, Purdy’s 6.6 air yards per target ranked 33rd among 37 quarterbacks with at least 200 plays under their belt. San Francisco’s game plan was clear; set up an overwhelmed passer with easy throws, then let his playmakers carve out space after the catch.

This wasn’t the case Saturday afternoon. Each of his first three passes cleared at least 15 yards before getting to their target. After attempting 12 deep throws (20-plus yards downfield) in seven games during the regular season he threw 10 in the first half alone. And, more often than not, he missed.

via RBSDM.com

This did not slow the 49ers offense. In fact, it was integral to their success. Eight of San Francisco’s first nine drives ended in points, closing the door on a Seahawks team that came out swinging. How’d that happen?

It worked, in part, because Purdy’s sudden willingness to throw downfield — he finished the day with an average throw depth of 11.7 yards —  scrambled Seattle’s safeties deep. So when he *did* complete his passes, mostly near the line of scrimmage, his stars had room to run and demoralize a rowdy defense.

There’s no better illustration of how this Niners offense works than a two-play stretch early in the second quarter. Facing first-and-10 in plus territory, Purdy blanked an open Deebo Samuel to lob a pass deep downfield, in coverage, where only the Seahawks had a chance at it. It was a bad read and a bad throw.

The very next play, with Seattle’s linebackers afraid of getting beat up the seam against a suddenly lively downfield passer, he hit George Kittle 5.5 yards beyond the line of scrimmage. The space afforded by deep threats and vertical routes elsewhere cleared enough room for the star tight end to turn it into a 14-yard gain and a first down.

This was enough to discombobulate the Seahawks and eventually make those long throws that failed to click in the first quarter easier as well. Here, Kyle Shanahan keeps Kittle, Christian McCaffrey and Deebo Samuel near the line of scrimmage against a three-man rush.

There are eight men in zone coverage, so there shouldn’t be room to operate deep. But three All-Pro playmakers are sidled up next to a rookie QB with a penchant for throwing short passes. So when Purdy puts the ball in the air, the Seattle second level looks like this:

That’s five defenders (including one not in frame) sitting on three players and their short routes. It creates a bubble for Brandon Aiyuk, who sneaks in front of the safety help deep and makes an easy catch for a 31 yard gain.

This was football judo. Shahanan leaned on the Seahawks one way, then had Purdy throw his weight in the opposite direction to flip the Seattle defense on its back. Pete Carroll’s defense never knew what to expect and was left playing catchup all afternoon to a quarterback who threw for 332 yards on 30 attempts despite completing only 36 percent of his deep throws.

Of course, those numbers were bolstered by the 49ers doing extremely 49ers things. They padded their league-best yards after catch numbers through stupefying athleticism.

This is how Brock Purdy wins; by flipping the script and creating opportunity even when missing throws. The rookie wasn’t as good as his 131.5 passer rating suggests, but he executed his gameplan to a T, minimized mistakes and burst like the Kool-Aid man through slivers of opportunity the Seahawk defense presented.

Don’t let that sell him short. Purdy also shined brightly under Saturday’s spotlight in a 41-23 win.

This is terrible news for the rest of the NFC. The 49ers offense rolled while relying on its normal run-after-catch wizardry. The 49ers offense rolled while botching deep balls. The 49ers offense rolled because Purdy rose to the level of his superstars and made you worry about him in every facet of the game.

Factor in more than 150 rushing yards and more than eight yards per carry from McCaffrey and Samuel and you’ve got so much more to plan around when you face San Francisco than just a brutalizing defense.

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