The offense Lincoln Riley took over at Oklahoma in 2015 was much different than the one he left behind at East Carolina. The Mike Leach disciple had been running more of a true air raid with the aptly nicknamed Pirates than what had been featured at Oklahoma.

The Oklahoma system he was walking into had just put freshman RB Samaje Perine at 1,713 rushing yards. The Sooners had been mostly 21 personnel (two RBs, one TE), fielding a massive OL led by 330-pound tackles Tyrus Thompson and Daryl Williams, with 250-pounders TE Blake Bell and FB Aaron Ripkowski prominently involved.

Riley’s last East Carolina offense didn’t have anyone hit 1,000 rushing yards, but put two different receivers over that mark. QB Shane Carden threw for 4,736 yards and 30 TDs.

Neither of the Sooners’ big tackles nor the FB/TE tandem remained for Riley, but the Sooners were still stocked with big freaks along the OL, and Perine was being joined by potential star RB Joe Mixon. Oklahoma was also returning lead receiver Sterling Shepard and QB Trevor Knight while welcoming the eligibility of transfer Baker Mayfield.

What Riley did with all of those parts was build something different than either of the old offenses at OU or ECU. Riley found a balance that put the Sooners back in the Big 12 driver’s seat, and after two years as OC, he’s taking over for Bob Stoops as head coach.

Air raid + run game = head coaching opportunity

The challenge of coordinating an offense at a place like Oklahoma: maximizing your advantage of NFL talent in the trenches, while also respecting the league’s “we aren’t afraid of shootouts, but you should be” ethos.

Here’s a glimpse into what a typical Oklahoma play would look like before Riley:

Ripkowski and Bell block at the point of attack, and Knight has simple options on the outside, if he doesn’t like what he’s seeing in the box. Perine takes a downhill path from the pistol formation, aiming for the play side A-gap and cutting back.

This was a solid offense, and despite Knight’s struggles with turnovers, the Sooners were held under 30 points only twice in 2014: once in a debacle against Baylor and again in their bowl against Clemson. Putting big people on the field and bowling over diminutive Big 12 defenses wasn’t a terrible idea.

However, it wasn’t enough to outscore everyone on the schedule, like they’d done in the past. They scored 40 or more points four times in Big 12 play, as opposed to their eight times in 2008.

When Riley took over for 2015, they continued to feed Perine and run behind a massive line, but the system was considerably different:

There are no FBs or TEs on the field here, and Riley added this GT counter play to give them greater potency from four-wide formations. Without a FB or TE, the Sooners made use of QB reads and pulling linemen.

Riley also made the most of Mayfield’s superior passing acumen and Shepard’s ability to run routes from multiple alignments, to bring the passing game back to standard.

(Also notable: the way Baylor’s star nickel, Travon Blanchard, bounces off Mayfield.)

Riley brought a balance.

From 2010 to 2013, Oklahoma had been a spread passing team with QB Landry Jones. In 2014, they were much more run-centric. With Riley, they re-embraced spread sets and passing, but maintained their downhill run identity.

Mayfield brought a swagger that helped Riley mold an identity, combining a smashmouth mentality with the finesse of the air raid.

A 6’, former walk-on QB sticking a hand in the face of a safety who’s being pancaked by a fullback, then standing over the defender in the end zone, is pretty much the pinnacle of an evolved, smashmouth/air raid identity.

In 2016, Oklahoma finished first in the nation in offensive S&P+ and averaged 47.7 points in conference play, becoming the first team to go undefeated in Big 12 play since the league instituted round-robin scheduling in 2012. Mayfield and WR Dede Westbrook were Heisman finalists.

And now that Stoops and Perine are gone?

In 2015, Perine ran for 1,349 yards at 6 yards per carry while Mixon added 753 yards at 6.7 per carry. This came despite the Sooners turning over both starting tackles and their FB/TE tandem.

In 2016, those pieces all returned with a stronger understanding of Riley’s tweaks. Perine ran for another 1,060 despite injury, while Mixon had 1,812 yards from scrimmage.

Either due to Riley’s preferences or Mayfield’s tendencies as a passer, the focus shifted from moving Shepard around to get him open (1,288 yards in 2015) to hitting Westbrook on the weak side (1,524 yards) when opponents would load up to stop the run.

Those skill players are all moving on. The heart of the returning talent is in the middle. Riley’s offense returns every starting OL, Mayfield gained back his lost year of eligibility, and FB Dmitri Flowers and TE Mark Andrews return.

These two big guys aren’t quite the players that Ripkowski and Bell were. But Flowers has some route-running savvy and solid hands ...

... and Andrews is more of a flex TE and possession receiver, mostly using his 6’5, 250-pound size to punish opponents after he’s used his quickness to get the ball.

The best package for the Sooners in 2017 may be 21 personnel once more ...

... yet with a spread flavor, due to the athleticism of Flowers and Andrews. From that grouping, they can mix their downhill, counter run game with outside pass options for Mayfield.

They can play a smaller, speedy receiver like JUCO transfer Marquise Brown or Kentucky transfer Jeff Badet off the line and free from press coverage, because Andrews (Y) is up on the line:

Then they can run smashmouth spread concepts with big blockers at two different spots. Flowers (H) is executing a lead block for the running back, while Andrews is getting leading for the receiver (Z). Mayfield is waiting to see how the nickel (N) responds.

It’s also possible that OU will make Andrews the new top target and 1,000 yard receiver. With his ability to be a big target in the seams, the Sooners can present unique threats on plays like the one above or in sets where they load up the boundary (the narrower side of the field):

With Andrews (Y) in confined space, opponents have some difficult choices.

Having the linebacker (W) on Andrews risks OU using motion to force the W to cover a small receiver. And the defense has to worry about its 200-pound nickel holding up if the Sooners run to the wide side behind the 245-pound Flowers. Or they can have a 6’ nickel try to cover the 6’5 Andrews.

Most spread teams don’t love putting their slot receiver in the confined space of the boundary, since their principal aim is to get that guy in open grass. That’s not necessarily true for OU here. OU’s ability to blend size, power, and finesse in this package allows it to enjoy the best of both spread tactics and downhill football.

Riley earned his shot to take over at Oklahoma by living that air raid life and turning a former two-star Texan into a star passer at East Carolina.

When he came to Norman, he found himself in charge of an offense that liked to charge downhill on smaller Big 12 defenses. Now that he’s taken over as head coach, it looks like that’ll remain the MO, just with a modern spread tweak.