The Frost Effect: Protecting the Backside on Runs

Nebraska fans got their first look at the Scott Frost offense in Husker red yesterday during the 2018 Red-White Spring Game.  Although Frost called the game “vanilla” from a scheme perspective, we got to see several of Frost’s running game concepts along with a nice mix of passing plays.  We’ll take a look at individual schemes over the summer, but for now let’s focus on how Frost protects the back side of his running plays, a couple of which featured heavily in the Red-White Game.

Beyond the tempo, one of the most notable aspects of Frost’s offense is how it divides the defense in the running game.  On any given run, you have the front side (where the run is intended to go) and the back side (where the cut back lane typically opens):

Front Side Back Side IZ.jpg

The front side of a run is where the run blocking concept occurs.  In the play above, that’s inside zone to the right.  It was a staple of the Mike Riley offense, and Frost, from his Chip Kelly lineage, uses it as a core run as well.

The differences between the Riley and Frost offenses, however, come in the back side of the play.  Before we get to the “how,” let’s talk about the “why.”  Back side defenders in pursuit frequently prevent runs from turning into big gains.  In the above play, it could be the FS filling into the cutback lane.  It could also be the DE running flat and getting to the RB before he hits the line of scrimmage.  In either one, you’ve allowed a back side defender to play the front side of the play, tilting the numbers game back in the defense’s advantage.

To take a running game to the next level, the offense must find a way to separate the field and hold those back side defenders so they can’t pursue to the front side run concept.  When an offense pulls it off, you see gaping holes and RBs breaking into wide open space.  So let’s look at the “how” in the back side of Frost’s running plays, which he accomplishes with a variety of methods.


If you’ve watched the Frost offense for any amount of time, you’ve seen the bubble screen as one way he protects the backside of his runs.  I talked about it in my last piece on the Frost offense, so we won’t dive deep into the bubble here.  It showed up in the Spring Game on the Kade Warner touchdown, and you’ll see it repeatedly throughout the year.

A less discussed concept is how he involves the TE in protecting the back side of his runs.  The primary way is the TE arrow screen RPO:

Arrow TE.jpg

Rather than having the TE block the back side DE, Frost instead runs an arrow screen away from the inside zone run while the QB reads the back side DE.  This concept removes two back side defenders from pursuing into front side run support: the alley player must react to the arrow screen and the back side DE has to honor the QB on the read.  The result is the front side of the play becomes 1 on 1 match ups (3 DL, 2 LBs, and 1 SS versus 5 OL and 1 RB).  That’s exactly what you want in a running play.

After a while of getting beat up on front side runs, backside defenders start to naturally flow play side.  And the TE arrow RPO has an answer for that.  A DE that chases the RB leaves the QB running free on the read.  An alley player that chases the inside zone play side leaves the TE arrow wide open.

Nebraska went to this concept several times in the Spring Game, frequently resulting in chain-moving gains:

TE Arrow Screen.gif


Another way that Frost protects the backside of runs is through his use of the triple option.  This is a red zone alert play for Frost’s offense, and whenever you see split backs inside the 20, you should be thinking it:

Split Backs Option.jpg

The front side is just standard inside zone read.  The running back runs the dive path while most of the OL and the TE blocks the zone front side.  The QB reads the end man on the line of scrimmage and will decide to give or pull to the RB depending on what the defender does.

Where it gets tricky, though, is on the back side away from the zone run.  To prevent those backside defenders from chasing the inside zone run, Frost will bring the second back (quite frequently a wide receiver) around behind the QB as the pitch man in an option play.  If the DE chases the first RB on the inside zone read, the QB pulls it into the option play.  The QB’s second read is the alley defender and he decides to pitch or keep off that defender.  You also see the backside OT work out away from the inside zone, looking to take on the apex defender.

In the play below, resulting in Adrian Martinez’s first touchdown, we see Tyjon Lindsey as the second back, Matt Farniok wipe out Will Honas as the apex defender, and no alley defender showing up to stop Martinez’s path to the end zone:

IZ Triple Option.gif

Watch what the action does to inside LB Jacob Weinmaster.  He initially steps with Tyjon’s motion before reading inside zone and stepping front side to play it.  He realizes too late that Martinez has kept the ball and can’t get back to the alley to play the option.  When that happens to the second level of a defense, you’re going to put up a lot of points through the running game.

Although they didn’t show it in the Spring Game, Frost will also frequently motion a WR back into the formation where Tyjon lined up.  They can do that from the opposite side of the field or from the boundary depending on what they’re seeing from the defense.

Bash Plays

Although Frost has certainly put his own stamp on the offense, Chip Kelly’s influence still heavily remains.  The third way that Frost protects the backside of runs, directly from the Chip Kelly playbook, is through the use of “Bash” plays.  Bash is jargon for “back away” plays, in which the QB and RB (or WR in jet motion) exchange assignments.  The QB becomes the runner to the front side of the play while the RB or WR runs the assignment to the back side of the play:

QB Bash Read.jpg

In the Bash Read above, the line blocks on a standard inside zone path to the left.  However, the QB now becomes the ball carrier on the inside zone.  He reads the back side DE and gives to the jet motion WR if the defender crashes down.  If that DE widens, the QB keeps the ball and runs the inside zone play.  This can also be used with several other run blocking concepts.

There are two immediate benefits to this.  First, if your QB is a true running threat, it makes him the primary ball carrier behind the bulk of the run blocking scheme.  Second, it’s a great concept to run if you’re facing a back side DE fast enough to play the QB and the front side run on a standard running play.  By moving to a Bash concept, you make that back side DE play a much quicker RB or WR, thereby taking away his ability to play two for one back to the front side. 

Understandably, with the QBs wearing green jerseys, Bash wasn’t going to be a featured concept in the Spring Game.  But it will be during the regular season just as it was under Frost at both Oregon and UCF:

Frost Bash.gif


The final way that Frost protects the back side of his running concepts is through the use of ball fakes.  With inside zone read being a staple concept for Frost, he must protect it from a variety of formations.  When the offense lines up in a formation that doesn’t lend itself to perimeter screens or the use of two-back option plays, Frost will frequently use ball fakes as a way to attack the back side.

In the clip below, he does this by having the QB and RB initially fake the inside zone mesh.  This gets the inside LBs to step down expecting the play to hit the front side.  But instead, Frost then turns this into a speed option look to the back side of the play.  The TE widens while the QB options off the DE:

Fake IZ Option.gif



I thought the Spring Game was a nice introduction for Nebraska fans to the Frost offense.  Both teams repeated ten or so concepts to give the players a sense of the timing and mastery necessary to run them, and they still created enough space and tempo to give the fans an exciting game.

We also saw how the offense can meld itself to different types of QBs.  Adrian Martinez is an outstanding option runner still learning the nuances of the college passing game.  When he was in, you saw more option and various read-based runs designed to get him into space.  By comparison, Tristan Gebbia isn’t anywhere near the runner that Martinez is, but he’s considered by many to be a better pure passer.  Gebbia featured on the vertical passing game, and although he didn’t run nearly as often, the offensive staff still found a way to get Gebbia a handful of opportunities in the run game.

Net/net, it was a good start.  A handful of pre-snap procedure penalties and two ill-advised interceptions prevent it from being a great start, but there is plenty of time over the summer and into fall camp to clean that up.  And as the Red Team’s 508 yards showed, the offense has a bright future in Lincoln.

7 thoughts on “The Frost Effect: Protecting the Backside on Runs

  1. Just another Sker fan

    In your opinion, which qb is better suited (assuming they are all 100% familiar with the offense) to run Frost’s system? I was pleasantly surprised with the tight end group. Jack Stoll looked the part for sure! Didn’t hurt that he put his shoulder down and bowled over someone. Man that was awesome.

    1. RK

      Long term, it’s Adrian Martinez. With what they like to do in the running game, he’s the only one that gives them access to all their concepts. Short term? Depends on who gets up to speed on the offense and can protect the ball.

      I’m of the view that Martinez will be the starter by the end of 2018, if not sooner. They need to prepare him for 2019, and using a transition year in 2018 takes away the sting of playing a true frosh.


    1. RK

      Thanks Eddie. I can assure you Urban Meyer and the rest of the Big 10 already know about anything I post. The All 22 is, and has been, widely available for them, and they have a fleet of GAs/support staff doing what I do.

      I do know some new stuff coming up, but my rule is I don’t post about it until after it happens. I also don’t post our specific terminology with any of the articles.

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