49ers Playbook: Run Game Variants and the Evolution of Chip Kelly

In the first part of this series, I covered the primary offensive formation and the inside and outside zone runs. Today we’ll look run game variants.

In the first part of this series, we covered the base running offense and formation that head coach Chip Kelly uses, first in his time as head coach at the University of Oregon, then with the Philadelphia Eagles, and now with the 49ers.

Briefly, the base offense flows through the inside zone running play. Everything revolves around getting the defense to remain in their base defense. When defenses cheat to take away what Kelly’s offense does best, he’ll install a new wrinkle here and there build on the successes of the previous series or games.

There have been numerous concerns that Kelly has failed to evolve the offense beyond anything he used to running. But through the first 8 games, fans should be encouraged by what they are seeing, if for nothing else than he is doing everything he can to put the team in a position to be successful. Players are getting open, offensive linemen are blocking and opening running lanes, but the quarterbacks are struggling to make plays. That’s tough for any team to adjust to in in-game situations.

So what are we seeing in terms of this offensive evolution? Kelly has gone to implementing more run game variants than he did in his time with the Eagles. Through eight games, we’ve seen more zone read, power, counter, split zone, and toss/sweep plays that have complemented the running game quite nicely.


The zone read should not be unfamiliar to 49ers fans. It’s the play that made quarterback Colin Kaepernick such a dangerous dual threat in 2012.

The zone read works a bit differently in Kelly’s offense that it did under Harbaugh. If the offense finds itself outnumbered in Chip Kelly’s numbered blocking scheme, the offense will audible to a zone read to flip the numbers advantage in the box and allows them to account for the unblocked defender. It is not, as many fans think, an opportunity to for the quarterback to run the ball. As he noted at a 2009 coaches clinic:

We want the ball in the running back’s hands. We do not want the quarterback carrying the ball. The option can put the ball in his hands, but the defense can force it out of his hands. We want the quarterback to give the ball unless he cannot.”

The zone read effectively makes the quarterback a blocker without having to touch a defender. The defender who was once unaccounted for is put into conflict — Do I attack the running back or the quarterback? — and made wrong on every play.

The play starts with the box numbering or the numbering to the play side specifically.

At the snap, the quarterback reads the unblocked defender, usually a defensive end.

If he crashes and follows the running back, the quarterback will keep. If he stays home and keys off the quarterback, the quarterback will hand the ball off to the running back.


One compliment to the inside zone and zone read is a gap/man scheme blocking play known as the power run. Instead of relying on traditional zone blocking to open a running lane potentially anywhere along the offensive line, the power run seeks to create a new gap by using a double-team block and a pulling lineman at the point of attack.

Power has three main elements that define the scheme: 1) A double team at the point of attack, 2) a kick out block of the EMOL (end man on the line of scrimmage, either a DE or an OLB in a 3-4), and 3) a lead block through the resulting hole.

Kelly’s offenses very rarely take snaps from under center, which can be problematic for an offense looking to conceal its intentions. Teams that run out of shotgun have a tendency to tip the direction of the play based on the running back’s alignment. For example, with the inside zone, if the running back is offset to the quarterback’s left side, the run is designed to hit to the right side of the offensive line.

Running power gives Kelly’s offense a chance to take advantage of a defense that over-pursues to one side. In Kelly’s shotgun version of power, the play can either hit to the same side as the running back’s initial alignment or the opposite side.

In either case, there is a misdirection element, combined with the double-team down block, makes the start of the play look a lot like the inside zone. The key is the middle linebacker reading the down block and flowing that way to where he thinks is the point of attack, not realizing that this rides him out of the true point of attack.


In an expertly detailed piece for The Ringer, Chris Brown (of Smart Football and formerly of Grantland) noted how adjustments would need to be made if Kelly is to sustain any kind of success in his tenure with the 49ers.

And this season, the evolution that Brown alludes is happening. Each week we are seeing some new wrinkles but most notably, the evolution began in week one against the Rams. The most notable was the introduction of an old-school Joe Gibbs run concept: the counter trey.

The linemen to the play-side block down on the defensive line to create a wall, while two backside blockers pull to the play-side.

The backside guard always pulls and is responsible for kicking out the playside contain player, while either the backside tackle, H-back, or tight-end will pull and then lead into the hole for the running back.

Counter trey is an excellent complement to Chip’s base run concepts for two reasons. One, it serves as a tendency breaker. As I highlighted above, the alignment of the running back and tight end would often tip both the direction of the run and the type of run. Counter trey goes against both of those tells.

Two, it creates hesitation. The initial movement of the offensive line with their down blocks and double teams, looks like a zone running play until the pulling blockers hit the hole. This causes just enough hesitation for the defense that the offense is able to get up to the second level and create a running lane for Carlos Hyde.


Vince Lombardi’s power sweep is perhaps the most famous play in football. Modern NFL offenses rarely run this play now but Kelly has installed it in his game plan every week since the Tampa Bay game in week seven. Unlike the classic Lombardi sweep, Kelly’s sweep is effectively a modern take on the classic play.

The blocking is similar to power and counter in that it uses a gap/man blocking instead of zone. There are downblocks by the play-side linemen and pulling blockers that lead the way for the running back. Instead of using the guards to pull and lead block in the classic sweep play, Kelly utilizes a guard-center combination with the play-side guard as the lead blocker.

Another key difference between the classic sweep and Kelly’s sweep is there is an added “read” element to it much like the zone read. The read sweep leaves an unblocked defender as a read man and is often accompanied by arc motion going away from the play (like Lombardi’s Sweep). The play side tackle blocks down, and the pullers work through to the second level.

The unblocked read can either be the 0, 1, 3, or EMLOS (end man on line of scrimmage). Who ever it is will remain completely unblocked, but hesitates just enough to make himself a non-factor in the play.

The beauty of this read element is it can block interior defensive lineman with no QB run threat. 

The center and play side guard pull wide, attempting to stretch the defensive front 7 horizontally, while the play side Tackle blocks down.


Similar to the sweep play above is the “toss sweep.” There aren’t many running plays in Kelly’s playbook that get the running back going on the same side as his alignment but this is one of them.

The blocking is similar to the read sweep with the blocking but instead of the center/play-side guard combination, the center and play side tackle lead the way and the running back takes the toss on the same side of his alignment. Every other lineman tries to get outside leverage on their man.

There is a built-in delay element — by having the running back slow-roll into the play, having the quarterback take an extra step or two before tossing the ball, or both — so that the ball-carrier doesn’t outrun his blockers.

It’s clear the offensive evolution Chip Kelly was in need of is taking place before eyes. These breakdowns should give you key indicators to watch for in certain plays and help you identify what the assignments for each players are. The 49ers have the playbook to be successful. Talent is another matter.

All images courtesy of NFL.com.

All statistics, records and accolades courtesy of Pro Football Reference unless otherwise indicated.