49ers film room: How the 49ers and Kyle Shanahan schemed around Seattle’s loaded fronts
49ers play action concepts put Seattle's linebackers in a bind for much of the game.
On the downs where Seattle really sold out to stop the run, Shanahan dialed up play action, and from the very first play of the game, a wide open miss to Deebo on a deep crossing route, it was clear Seattle was going to sell out aggressively to stop the run. This left the middle of the field wide open for those crossing routes.
On play action, Purdy was 15/16, 192 yards, and three touchdowns. The one miss might have also been a touchdown had receiver Brandon Aiyuk not stopped running.
On the very first play of the game, the 49ers came out in 21 personnel versus Seattle’s base 3-4 defense with single high coverage. The play call was a basic high low with a high corner route and a deep crosser underneath. It was the perfect play call to open the game and it showed the 49ers what the Seattle defensive game plan would be for the majority of the game.
The play call is designed to put the coverage defenders underneath in a bind by basically taking advantage of their coverage rules for covering crossing routes. Typically, the routes on this play would be flipped with the dig/crosser coming from the left and the corner coming from the right.
Shanahan knows that when this happens, the linebackers will “robot” (roll over and back) to locate the crossing route. If they see zone run action one way, they will “roll over” their back shoulder and turn to locate the crossing route from that side of the formation. Knowing this, Shanahan flipped the routes to put the underneath defenders in a bind when they couldn’t find the crossing route.
They’re also not traditional crossing routes, they’re deeper dig routes, making the distance they have to cover if they do find it that much greater.
With how the Seahawks distribute their zones, the strong hook and flat defenders also have to keep eyes on the flat and checkdown routes.
You can see how the underneath defenders try to robot the crossers but there are not crossing routes and they look lost. This leaves a void in the middle of the intermediate areas of the field. Deebo is wide open on the crosser coming from right to left but Purdy throws a floater between Deebo and Aiyuk. It’s likely that the pass just got away from him.
Shanahan came back to the same play again at the start of the second quarter in 21 personnel again, just flipped.
This time the receivers were Aiyuk and Ray-Ray McCloud with Aiyuk on the in-breaking route and McCloud on the high corner route.
Seattle doesn’t chase the run so aggressively and linebacker Cody Barton zones off into coverage where he sort of “robots” the in breaking route from Aiyuk. This time, the robot defender is Cody Barton (No. 57), and again, he robots where he things the crosser should be coming from but it isn’t and he sees the dig but he’s unable to affect the throw.
Purdy waits a half second longer until Aiyuk clears into the next window before throwing it over the middle.
This next play has generated a lot of conversation on social media over quarterback reads, where Purdy should have thrown the pass, why he threw the pass where he did, and why Aiyuk stopped running on the route.
The play is a creative way to get to the “yankee” concept (post over a deep crosser) or what the Shanahan tree calls “burner.” It is a shot play designed to be read from high to low with the post as the first read and the crossing route as the second read.
Pre-snap you can almost tell where the play might go against single high coverage with the safety playing the post to take away the shot play. Under the post, the crosser has the potential to come wide open.
The crosser is open almost immediately as Deebo clears the intermediate zone of the field. No quarterback would be faulted for throwing a quick pass downfield to the crosser especially with the safety sitting deep. But Purdy has time in the pocket and can survey what’s going on in front of him. The post safety jumps the crosser, at the last second as Purdy is setting up. He sees this and immediately fires downfield to Aiyuk but about half down his post stem, he stops.
Aiyuk probably thought the ball was going to Deebo or already to Deebo. It’s the only explanation for why he stopped because a receiver should never stop on his route until he knows the ball is not going to him and he can set up his next actions to block downfield. If he keeps running, that’s likely a touchdown 1-on-1 with corner Mike Jackson.
In a perfect world, Purdy throws that ball to Deebo anyways. The post safety was never going to get downhill fast enough to make a play on Deebo and Deebo likely would have scored too as he only has to beat Aiyuk’s defender. But this isn’t a perfect world.
Purdy made the correct read in my own opinion and the play’s outcome rests more on Aiyuk’s shoulders than anything else. However, the better throw might have just been the crosser anyways since yards and points come at a premium this time of year.
The 49ers have probably tried more deep shot plays with Purdy than they have with any other quarterback in Shanahan’s tenure. One they’ve tried twice since week 17 is the corner post (CP) concept.
Corner post is another designed shot play if defenses want to cut the crosser while not anticipating the corner post route. Usually the corner post is called because the backside corner jumps the crossing route and leaves the deep third zone or a two deep safety jumps the crosser and leaves the other half safety alone with the CP route.
Here the Seahawks are in cover-2 with what looks like just a 2-man rush for some reason while taking away all the underneath zones with defensive linemen and linebackers so other defenders can drop to the intermediate areas and take away the crossing route that has been open every single time it’s called.
Still, no one picks up the crosser as the safety passes it off to the next defender so he can help on the CP route. Purdy fires to Kittle who catches it for a 23 yard gain.
In part three, we’ll look at how Shanahan put the rest of the Seattle secondary in conflict by looking two of the late game explosive pass plays.