In 2019, head coach Kyle Shanahan installed and called more gap scheme runs (counter and power) in their gameplans each week to complement their wide zone running scheme. The result culminated in a Super Bowl run with one of the league’s most potent running games.
The plays were primarily run from under center in heavily condensed personnel formations out of 21 and 22 personnel. Old school football at it’s finest. In 2020, Shanahan and run game coordinator Mike McDaniel took the running game and evolved it further with jet motions to cause misdirection similar to the Rams running game adjustments this season.
To be fair, they utilized the jet motions in 2019 as well but primarily with wide receivers. In 2020, they were also using fullback Kyle Juszczyk and the tight ends more and more on these motions to create space and easier blocking angles.
Old school run concepts, new school flavor
The counter is an old school gap scheme run that all teams run from traditional under center and mostly two back 21 personnel formations. The backside guard usually trap blocks or kicks out the defensive end or first up field defender while the rest of the line down blocks away from the point of attack. The use of a fullback adds an extra blocker to lead up through the hole, the down blocks, and the trapping guard.
Here is an example of the 49ers running a basic GF counter (GF=Guard-Fullback lead blockers) from 22 personnel (two backs, two tight ends, one receiver) against the Steelers in week three. The down blocks and pulling guard plus the lead blocker (fullback in this case) help the offense gain a gap back to the front side and create a running lane for the back to maneuver through.
Another element in the 2019 install of this concept is adding the jet or fly motion. Jet or fly motion on these gap runs does three things: 1) pulls a defender out of the box, 2) bumps the defense over a gap to the side of the motion and messes with the run fits, and 3) makes the offensive line blocking angles easier in space.
In this play from the same 2019 game, the 49ers are in 22 personnel under center running jet counter to the right. The fly motion messes with the gap assignments as the defenders have bump over a gap due to following the fly motion. Left guard Laken Tomlinson (No. 75) kicks out the defensive end with a trap block while Juszczyk lead blocks into the hole.
In week 16, the 49ers' run game gashed the Cardinals for 227 yards on 30 attempts, including a zone-read keeper executed perfectly by Beathard. And they did it through mostly gap scheme runs (counter and power).
1st quarter 9:29, 2nd-and-2 at the SF 26
The play call is the same as the fly counter above, but this time, the 49ers are in the shotgun in 12 personnel (one back, two tight ends) and running GU counter instead of GF counter (U is the 2nd tight end in 12 personnel).
The fly motion by receiver Brandon Aiyuk pulls a defender out of the box and gets the second-level defenders to bump over a gap just before the snap.
As a result, the defenders are unable to fall back into their gaps to stuff the run. The linemen also have easier blocking angles. Kittle’s block prevents the defender from being able to “spill the puller,” a common technique used by defenders to turn the puller back inside by attacking his upfield inside arm and forcing the running back to cut away from his intended path (also known as a “wrong arm” technique). Jeff Wilson is able to run straight up the middle behind his blockers for an eight-yard gain.
On the first play of the game, Shanahan used the same counter principles but used the tight end as the puller (Y) and fullback (F) to lead block for Wilson. Kittle starts on the motion across as the puller and takes out the defensive end while Juszczyk leads to the second level and seals off the defender from the running back path.
The 49ers called the play several more times with success in the game and with the tight end as the lead blocker on some occasions.