49ers film room: The Shanahan offense “no hot routes” theory

There is no shortage of misinformation from content creators and analysts relating to the 49ers offense and it's hot routes or easy answers for the quarterback.

Photo by Thearon W. Henderson/Getty Images

With the 49ers at a stale 4-4, many fans and content creators this season are looking for answers as to why and are looking to place blame on anything they can find. It’s understandable, there’s more than enough on film on the field and off the field (this past offseason) to analyze and critique as to why something feels off about this team.

The one constant criticism amid the recent losses before week 8 that keeps coming up is the theory that head coach Kyle Shanahan gives Brock Purdy no hot routes or no easy answers built into the play. This just isn’t true as there are hot routes on every play, sometimes two or three, and as Brock said prior to their week 8 game, “every play has answers.” It’s up to him to get the offense to those answers.

The real issue, that’s interrelated to the “no hot routes,” with Shanahan’s offense, is the constant free rusher problem even when there are enough blockers to block everyone who pass rushes the quarterback. I wrote two articles on it this past offseason hyperlinked here. That issue is still the one issue that looms large as the 49ers offense sputters week after week through four of their losses.

What is a hot route though? When a quarterback senses a blitz coming, he usually signals to his receivers to change things up. This is known as a "hot route." It prompts the receiver to switch from their original route to something quicker, like a slant or screen. This way, the quarterback has a fast option to throw the ball and dodge a sack or loss of yards. If the blitz doesn’t happen, the other receivers continue with their usual routes.

In most NFL offenses, there are already routes in the play that are designated as hot routes, as you’ll see in some of the Shanahan playbook art later on. On some plays, there are two or three designated hot routes that give the quarterback options depending on the blitz.

We’ll get to that issue a little bit in this article but to summarize it, opposing defenses are keying on how the center identifies the MIKE linebacker counter rushing against the protection slide. Meaning, wherever Brendel sets the strength of the slide, the defense is rushing the most guys away from it.

Kyle Shanahan has stated that he doesn’t want his quarterbacks doing anything at the line of scrimmage like changing the pass protection so they can play faster. After the Chiefs game, Shanahan stated that "When people blitz more than you have, you've got to throw hot."

Missed hot throws lead to media and fan confusion

Defenses are using the offensive line’s protection rules against them and are alert to how they will slide protection and Purdy’s only answer to it is ensuring he sees it right away and throws hot as opposed to making adjustments pre-snap like re-MIKE-ing the defense. He has the ability to call audibles to the next play called, flip the play, reset the play, etc., but he cannot reset the protection.

This means there are going to be instances where it’s not as easy to get to the hot route if he doesn’t know where the blitz/free rushers will come from. And that’s not entirely his fault. Often, when the defense gets a free rusher, it more often than not happens when the 49ers have enough blockers in pass protection but the defense finds a way to get free rushers for the reasons I mentioned above and in those two articles.

Even then, there are also times when he can see the free rusher in his field of vision but doesn’t read his pre-snap indicators correctly to confirm what he sees. These are recent misses by Purdy that are just meant to illustrate that there are hot routes despite the conventional narratives and wisdom thrown out there by JT O’Sullivan and other 49ers content creators. The quarterback just missed them.

On this first play from week seven versus Kansas City, Purdy is trying to hit Aiyuk on a glance/slant route with Juszczyk on a quick route to the flat. Juszczyk recognizes the coverage and adjusts his route to the flat as the hot route. He’s the second in the progression on this concept above but should automatically become the primary for Purdy and has a route adjustment for the blitz.

On this particular play, JTO first says there’s no hot answer (wrong), then assumes that Aiyuk’s route is the hot (also wrong), which is isn’t because of the wider split and time it takes to develop from there, then opines that there’s no good answers (wrong again). You can see the labeled hot routes in the diagram above. The answers are there. If there is no good answer, it’s because Purdy does not pick the right answer.

The blitz indicator is the alignment over the trips. The safety caps the the defender covering the the #3 receiver in the slot. That’s Purdy’s cue that he’s hot off the edge. His favorable alignment is the left with the fullback.

But he reads the progression like normal and tried to let Aiyuk’s route develop instead of drifting away from the pressure and hitting the flat. The result is an air mailed throw over the middle.

Where I would partially agree with JT is that the hot route to the right with Pearsall isn’t a great answer because it would take a little too long for that route to develop and it would be a difficult adjustment to get this hot route.

That’s where I take issue with this particular element of the offense. That hot throw is a bit unconventional in that it’s away from the blitz. Typically the hot route throw is into the blitz.

But as you can see in the play design above, there is a hot route into the blitz as well. But with two off the edge, it would be a more difficult throw, which is why the right answer is Juszczyk.

It’s unconventional but Purdy is more than skilled at drifting away from pressure and hitting a throw. And if the expectation is the quarterback is never going to get hit then he can’t play that way and won’t be very effective.

On another later throw in the second half versus Kansas City, Purdy had a hot answer in front of him, two of them, and just didn’t recognize the blitz again pre and post-snap. 

The blitz indicator for Purdy is the defender aligned over Juszczyk. There’s no world that exists where that is a pass rush stance for a defensive end. That alignment is man or zone drop.

That’s the indicator that another rusher is coming from somewhere and the motion doesn’t move the second level defenders, another indicator. That should tell Purdy the blitz is coming from somewhere int he second level in his field of vision.

But he drops back and reads out the progression like normal and doesn’t see the blitzing defender in front of him. Jordan Mason out of the backfield is the hot here along with Conley but Purdy never even considers that side and Mason is wide open out of the backfield and looking for the ball almost immediately.

Where are the hot routes

We’ve seen Purdy successfully complete throws to hot routes since day 1 in 2022 and we don’t think twice about them because they look like regular throws to regular routes but they are in fact hot routes. Some examples from 2022 and 2023 illustrate this.

Hot routes in the offense are all over place and depend on the play call and situation, where the blitz comes from, and where the quarterback knows he has pass protection.

They can be to running backs out of the backfield like here in week 8 to Isaac Guerendo in the flat. The Cowboys know where the pass protection is sliding to, away from the running back, so they overload the weak side of the blocking scheme with extra rushers while dropping the defensive end on the opposite side. Brock sees this and immediately flicks the ball out to Guerendo.

They can also be to tight ends chipping in pass protection who in a non-blitz scenario would be the third in the progression.

The Vikings send a 6-man pressure and get a free rusher at Brock. They know based on alignment and defensive back depth that a blitz is coming from somewhere. Since the pressure is from Brock’s left, he sees it and lobs the ball over the line to Kittle as the hot.

In his first real game action in 2022 coming in for an injured Jimmy Garoppolo in week 13 versus Miami, he came in and immediately hit an elite throw versus a free rusher in his face.

The 49ers are running their “chevy plaster” concept, a two man route combination to the right with a skinny post and a “chevy pivot” route which is just a stick route out of the backfield with the option to cut outside versus the leverage.

The defense has seven defenders hugged up to the line of scrimmage and pre-snap this looks like a cover-0 blitz.

Purdy has to figure out where the rushers are coming from. The pass protection slides to the left to the widest and most dangerous rusher on the offense’s left edge.

The rush only comes from four defenders but since the offensive line slide to the left, the free rusher comes off the right edge of the offense, and this makes him Purdy’s responsibility. Purdy sees it and fires the pass just before he gets hit. From snap to throw, he released the ball in 1.78 seconds. That’s some fast recognition.

Purdy recognized the blitz pre-snap and made a route adjustment on Kittle’s route to shorten the post route. The route is normally run at 6 steps before breaking to the post. Kittle shortened his route to 5 steps.

The change is significant because on a 6-step post route, the inside foot is the lead foot. On Kittle’s route, notice how he changes his stance to the outside foot up, this shortens the route to a 5-step route by the receiver.

The adjustment was likely communicated pre-snap in the huddle because there is nothing on the all-22 to suggest it was made at the line and Kittle lines up right away with his outside foot up.That’s one hell of an adjustment.

On Purdy’s first touchdown throw versus the Giants in week 3 of 2023, the Giants weren’t hiding their intentions with six defenders walked up to the line of scrimmage and five defensive backs in off-man to cover the five eligibles.

With five to block in pass protection, this meant that Purdy was responsible for the free rusher, where ever that rusher came from.

The play call has a built-in check for an all out blitz with a concept called “Pile,” and an out route with a “now” quick slant underneath it, both designated as the hot receivers.

The Giants are playing cover-0, an all out blitz with no safety help over the top for the defenders covering the five eligible receivers.

Rookie receiver Ronnie Bell is in the slot running the pile route to the front corner of the end zone with Giants corner Deonte Banks (No. 25) in coverage. Christian McCaffrey is out wide running the now slant under Bell’s out route. Bobby Okereke (No. 58) is in coverage on McCaffrey out wide.

The free rusher is Oshane Ximines (No. 53) off the left of the offensive line. He actually lined up offsides and drew a penalty on the play which the 49ers obviously declined.

Trent Williams smartly widens with Ximines off the edge to get him to widen before he turns to block inside and this buy’s Purdy another half second to throw. Purdy sees the rusher coming off the edge and quickly rifles the pass out to Bell in the front corner of the end zone.

Purdy probably could’ve hit McCaffrey on the now slant underneath, the easier throw but that’s not who Purdy is. He’s going to take more chances downfield and he’s making the ceiling for this offense higher than it was with previous quarterbacks on the roster.

In the Super Bowl, Purdy also hit a touchdown throw to Jauan Jennings early in the fourth quarter on the same concept as the one above, except he hit the “now” quick slant underneath the pile route.

On a touchdown throw to Jauan Jennings, the Chiefs are sending another cover-0 pressure. As with the cover-0 pressure above, the Chiefs are giving Purdy the same blitz indicators.

But this time Brock drilled Jennings in the chest with the throw and Jennings barreled his way into the end zone. The offense is running a “Pile” concept, an out route with a dart/1-step slant route underneath it to the right, both of which are the hot reads here.

The offensive line is in a full slide to the right, leaving the unblocked rusher to the left, and again, it’s not clear why they don’t adjust this pre-snap to the hot route side.

The routes on the left are not hot routes and take too long to develop. The Chiefs stunt their defensive end inside and send the linebacker around the edge, pulling in the protection and getting a second free rusher but this time Purdy drills the throw.

And for good measure, here is a quick cut-up early Shanahan 49ers hitting touchdowns on choice routes, the primary hot routes for running backs out of the backfield.

Choice routes remain a staple pass route in Shanahan’s offense because it gives the quarterback an easy outlet versus the blitz and gives the running back a 2-way go, allowing him to cut off the leverage inside or outside.

Outlook

There is no shortage of misinformation from content creators and analysts relating to the 49ers offense and what exists or does not exist my background with this information comes from talking with former players in Shanahan’s offenses as well extensive study of the playbooks that are shared around the internet coaching circles as well as Hudl cut-ups and video installs. I may not have the insight that JT has at the quarterback position but that doesn’t mean there can’t be insights and opinions that exist along side his or others.

Too often, fans will take his word as gospel, as well as others in the practice-squad-quarterback-turned-internet-analyst’s word, and use their words to confirm their priors instead utilizing them as a tool or resource to deepen their understanding of the game and quarterback position and the process quarterbacks arrive at through their decision-making, which is typically how I view their content. If you read this far, thank you, and I hope this provided some valuable context as to what hot routes look like and when they are used.