The 49ers had the most explosive plays in the NFL when lined up in 21 personnel last year

ESPN’s Matt Bowen put together a list of which teams excelled the most at 11 different personnel groupings, from five wide receivers to two quarterbacks. It should come as no surprise that the San Francisco 49ers were the most efficient and explosive out of 21 personnel, which Kyle Shanahan relies on more than any other play-caller in the NFL.

21 personnel (2 RBs, 1 TE, 2 WRs)

The team that ran it the most: The San Francisco 49ers logged a league-high 270 snaps out of 21 personnel in Kyle Shanahan’s offense last season, while also leading the NFL with 153 rushing attempts. It’s a combination of playcalling and personnel under Shanahan, with heavily schemed play-action throws and misdirection (pre- and post-snap), along with the ability to gain numbers with fullback Kyle Juszczyk in the running game.

The team that ran it the best: Also the 49ers. In 2019, San Francisco averaged 6.83 yards per play out of 21 personnel — including a league-best 32 total explosive plays — while posting 9.59 yards per pass attempt and 5.51 yards per carry. Think of the middle-of-the-field throws here for Jimmy Garoppolo, who led the NFL with 1,055 yards passing out of 21. Play-action and RPOs led Deebo Samuel, Emmanuel Sanders, George Kittle and Juszczyk all to the top 10 of 21-personnel receptions.

Plus, we know the running game can get going out of Shanahan’s two-back sets, where Raheem Mostert, Tevin Coleman and Matt Breida all averaged over 4.5 yards per carry on 21 personnel rushes. Want an example? Here’s an explosive play run from Mostert against the Steelers, illustrated by NFL Next Gen Stats animation. That’s how you scheme to create a running lane.

I found the play Bowen referenced. Misdirection is a big key to the 49ers running game. Whether it’s Juszczyk in the backfield starting his path one way, then altering it as he approaches the line of scrimmage, or a wide receiver going in motion, defenses are often caught off guard. That creates a crease, and that’s all Mostert needs:

Two plays before, Shanahan used play-action get Marquise Goodwin open deep:

That will be Brandon Aiyuk this season. Ideally, he won’t have to wait on the ball and can create yards after the catch. That’s one of my critiques for Garoppolo. He sees Goodwin. He knows he’s open. Throw it. That extra pat of the football makes a difference.

The play above also highlights why the 49ers 21 personnel isn’t like most teams. Juszczyk can light up as an in-line tight end or split out wide as a wide receiver, or, as Minkah Fitzpatrick found out, can be an effective slot receiver. That gives the 49ers flexibility to call any play they want when Juice is on the field. As you can see above, that puts linebackers in a “no man’s land” situation. Second-level defenders will always bite on run action, and if you have speed on the perimeter, you can create mismatches all game long.

I’m curious about whether Shanahan will evolve from his love for 21 personnel this season. If multiple receivers step up, could we see more 10 and 11 personnel? Or if Charlie Woerner, perhaps even Jalen Hurd, become receiving threats, will San Francisco lean on 12 personnel? The Niners have options; it’s only a question of whether they can execute.