49ers film room - How Kyle Shanahan sequences play calling part 2a: under center running game and under center run-pass options

Part 2a of this series looks at the under center running game and run-pass option concepts with Shanahan's play call sequencing.

In part one of this series we looked at how Kyle Shanahan and the 49ers offense structures the play action passing game to look exactly like the run game and how those two are tied together in their presentation. In this part, we’ll look at how they sprinkle in the run-pass option (RPO) tags to their run game and play action concepts out of under center and out of the shotgun (part 2b).

The 49ers run both pre and post snap RPOs but lately their primary concept is run from under center as a pre-snap read. In the pre-snap read RPO, the quarterback is either making a box-count read or a ratio read.

In a box count read, the quarterback counts the defenders in the box to determine if he has a favorable advantage in the run or quick pass tag (tags like dart, bubble, dump, topper, pop, etc). More defenders in the box than the offense can block: throw the RPO. More blockers versus a light box: give to the running back.

In the ratio read, the quarterback is simply counting the number of defenders covering the particular passing route on the RPO. He’s looking for a numbers and leverage advantage for the offense and reading the alignment of the defenders covering the pass concept. After a certain depth, usually about 7 yards, the quarterback knows there is not time for the defenders to adequately play the pass concept so he’ll throw if he has the defense outnumbered and out-leveraged.

The 49ers run both of these types of RPOs depending on who the quarterback is. With Brock Purdy, the 49ers played a bit more under center and ran primarily box count RPOs from under center. With Jimmy Garoppolo, who operated primarily out of shotgun later in his career with the 49ers, Shanahan elected to go with more of the ratio read-type RPOs (or post-snap read RPOs) and let Garoppolo read the leverage.

Under center RPO

The first thing to note about the 49ers RPO game is that they don’t typically look to throw the RPO tag in the play call until after they have established how the defense is going to play the run and seeing how they align to the formation. If they can get a tell on how the alignment and run fits distribute or can get a read on a backside defender that aggressively pursues the run, then they will more than likely come back to the RPO tag for a quick hitter.

First sequence/first play: 2018 week 2, 1Q, 1st and 10, 2:39 remaining

The 49ers line up in 21 personnel (two running backs, one tight end, two receivers) are running a toss crack to their left called “18-19 Cab.” “Cab” is a pin and pull toss sweep variation where the play side tackle will pull to the edge while usually a some combination of a wide receiver, fullback, and tight end will crack block the defenders inside.

The Lions indicate they are playing a zone coverage shell when fullback Kyle Juszczyk motion out of the backfield out wide outside the numbers. The motion leaves five defenders on the left side of the box from the center over to the in-line receivers, a total of five offensive blockers. 

Running back Matt Breida takes the snap behind a pulling Joe Staley (no. 74) out on the edge as receiver Pierre Garcon cracks down on the defensive end and receiver Dante Pettis (no. 18) works to the second level safety. 

On the backside of the play, tight end George Kittle (no. 85) is actually running a quick slant pattern into the middle of the field, but with the box numbers matching the play side blockers, the easy call is the toss, which goes for nine yards. Kittle’s assignment, however, is key.

First sequence/second play: 2018 week 2, 1Q, 1st and 10, 1:50 remaining

Two plays later, the 49ers offense came right back to the play above but flipped the formation and assignments to run “18 Cab Dump,” the RPO tag to the run call. It’s the same play just flipped the other way.

“Dump” is the tag for the pass route from Kittle called a “dump” route, basically just a quick pop pass route over the middle. The rest of the play call for the toss run is the same, just flipped to the right this time.

The Lions notice the same formation but flipped and align with an extra defender to the side of the formation they expect the toss to be run to. This time they line up with six defenders from the center over to the offense’s right to give them some leverage.

But with the same play call as above, Kittle is going to run right into the void the defense left for him, thus putting the Lions into conflict and showing why the RPO can be so effective at putting defenders into conflict.

Kittle goes out on the quick pop route over the middle into the void left by the defense as they chase the toss play. The backside defenders get caught flat-footed as they are expecting to have contain assignments on anything that cuts back against the grain. This springs Kittle open by about three steps and gives quarterback Jimmy Garoppolo an easy toss to Kittle. 

However, Garoppolo rushes the pass, doesn’t set his feet, and delivers one over Kittle’s outstretched hands. What would have been an easy 15 or 20 yard gain falls as incomplete but shows the way in which Shanahan’s offense works in sequence to play off a defense’s tendencies.

Second sequence/first play: 3rd quarter, 1st and 10 at DET 26, 14:45

The 49ers have a variety of ways to run their back side under center RPOs and have tags for them on a variety of wide zone, inside zone, and gap and man scheme run blocking schemes. This play is similar to the one above but it’s off of one of their wide zone run play calls, 18-19 Zap out of a 13 personnel (1 running back, 3 tight ends) YY wing formation call “West RT/LT Tite Slot.”

The 49ers are in 13 personnel running wide zone to the right with Alfred Morris. They are looking for two things specifically on this play: what does the backside end do and what does the backside linebacker do. They’re looking to see how each defender reacts to the run action on the backside of the play and how the defense aligns itself.

The backside defensive end is in the 6-technique defensive line spot so he’ll be looking to two-gap anything that comes his way. Since the run goes the opposite way, he crashes the the C-gap in between the tight end and left tackle. The outside linebacker in the B-gap off the ball will be looking to fill any gap that opens in the middle of the offensive that the running back could potentially cut back into. The tight end on the backside, Kittle, does not go out on a route. 

The run goes to the right and Breida hits the “bang” read of the outside zone between the #1 and #2 end men on the line of scrimmage. The defenders on the backside however, give the 49ers another key: they are going to crash hard on the backside to contain the line and prevent a cutback. 

Second sequence/second play: 3rd quarter, 2nd and 5 at DET 11, 13:22

Three plays later on the same drive, the 49ers were set up in the red zone to punch it in for a touchdown.

The 49ers come right back to the same exact formation except flipped this time, “West LT Tite Slot,” placing the YY wing formation to the left and the single tight end, Garrett Celek, on the right. The play call this time is “19 Zap Dart” with dart being the RPO tag and quick pop route over the middle from Celek on the back side.

The flip in the offensive formation causes the Lions to shift the 6-technique defensive lineman from the play above to the 3-technique spot between the guard and tackle and dropping an outside edge defender outside tight end Garrett Celek (no. 88) for backside contain.

The box count read suggests that the 49ers should pass the ball since they have only five blockers to the strong side to account for six defenders. The MIKE linebacker is shaded over the strong side A gap and the WILL linebacker is on the ball on the back side, indicating to Garoppolo that the “dart” tag is the correct option and where he should go with the ball.

Garoppolo makes the right read. As Celek releases down field, Garoppolo does the quick run fake and turns around right away and fires a pass to Celek, who’s route caught the defender flat-footed at the snap. Garoppolo plants the ball right at the numbers and Celek makes the catch and drags two defenders with him into the end zone for a touchdown.

In part 2b, we’ll look at the shotgun RPO concepts that the 49ers employ heavily as part of their running and play action passing game.