Oklahoma’s offense isn’t just the best in college football this year. It might be the best of the whole Playoff era.

The Sooners had some brilliant offenses earlier in the 2000s, but they took their perch as the offensive program in 2015. That was the year Baker Mayfield became eligible after transferring from Texas Tech and Lincoln Riley started as coordinator after Bob Stoops hired him from ECU.

OU is in its third Playoff in four years since then. The last three, it’s been No. 1 in Offensive S&P+. Mayfield and Kyler Murray have won the last two Heismans.

Yet the best endorsement of this unit is that the two worst defenses — by far — to ever make the Playoff are Oklahoma’s in 2017 and Oklahoma’s in 2018. When you have this offense, defense often doesn’t matter.

Some of Oklahoma’s dominance comes down to talent. Murray is an otherworldly athlete. The Sooners have four-star recruits all around him. But lots of teams with blue chip talent don’t have attacks nearly this good.

They play in the offense-oriented Big 12, but that doesn’t fully explain it, either. S&P+ is opponent- and pace-adjusted, and it consistently says the Sooners’ offense is better than anyone else’s. (And we saw last year’s team dominate the Big Ten champs and take the SEC champs to overtime, so OU’s proved it’s not just a conference thing.)

Oklahoma’s been smarter than most teams and created open space where other offenses might be challenged. That helped OU survive Mayfield’s exit, a Week 2 injury to star back Rodney Anderson, and one of the worst defenses in the Power 5.

The Sooners get at least 5 yards on 58 percent of their carries, the third-best mark in the country. You probably already figured they’re No. 1 in pass efficiency, but the run game is just as good.

It starts with a bulldozing line that has a consensus All-American at one guard spot and a first-team All-Big 12 guy at another. Collectively, they won the Joe Moore Award, which recognizes the best line in the country.

As you’d expect, Oklahoma loves to run counter plays, in which two backside linemen (or maybe one lineman and a back) wrap around to the front side of the formation and run people over. The counter, popularized by Washington en route to Super Bowls in the 1980s, is a cornerstone to this offense.

Here’s LG Ben Powers (the consensus All-American) and left tackle Bobby Evans clearing the way for a big Trey Sermon run to the right:

OU’s comfortable using counter-type plays in all kinds of formations, with different guys executing key blocks. Later on that same drive against Tech, OU goes left, with the other star guard, RG Dru Samia, leading. A fullback lined up at running back kicks an uncovered linebacker out of Sermon’s way:

Texas Tech’s second- and third-level defenders assume the play’s going wide, where Samia and others are going. That helps open the touchdown lane for Sermon.

All the eye candy entices defenders to key on the wrong thing for a split second, which is all the Sooners need. Elite spread offenses blend old-school principals with modern speed.

Later, when the Red Raiders have seven defenders at the line to deal with this kind of running, Murray uses play action off pulling blockers to go deep to a single-covered “Hollywood” Brown:

Here’s another way to run it, with an H back participating in the counter blocks:

Other times, Oklahoma uses counter blocking to set up Murray draw keepers, allowing the most electric athlete in the sport a head of steam. Watch Iowa State’s No. 2 hesitate for just a beat on Murray’s pump fake. It allows the running back to get a better blocking angle on him:

The plays don’t all have the same name, but they get the same things done: confuse defenders about which blockers are signaling what, give physical linemen a chance to get dudes out of the way, and draw in the defense so Murray can torch it.

The run feeds the pass and vice versa, but Oklahoma’s bruising front makes it especially hard to find balance against the Sooners. That they also have Murray and such a good receiving group makes defense more or less impossible for most teams.

The Sooners stretch the defense vertically by pairing that run game with Murray’s deep-strike ability. The way they do it horizontally is even meaner.

A football field is 53 and ¹⁄₃ yards wide. Oklahoma forces you to cover every inch of it, and with only 11 bodies on defense, that leaves lots of holes. At that point, the only thing that matters is that Oklahoma has faster guys than most opponents do.

The best example is the Sooners’ use of the triple option. On this play, Oklahoma’s running its usual brute-force counter play, but mixed with both a swing pass and a QB run:

Murray scores despite UCLA playing it pretty well. All it takes is this linebacker shifting slightly to follow the guy running the swing route for Murray to make it a footrace, which this QB’s always going to win:

Oklahoma’s running game sucks in a bunch of defenders, Brown’s speed moves the linebacker toward OU’s left sideline, and Murray takes over from there. If the LB had stayed close to Murray the whole time (the best choice, all things considered), the QB could’ve tried to beat him or just thrown the swing to Brown, who would’ve had to outrun one unblocked guy. And if UCLA had devoted any more resources to that side of the field, Murray could’ve just — oh, right, the first option — handed off to Sermon with a numbers advantage.

So, defense: have fun!

OU runs a similar version with zone blocking, stretching out receivers to make sure the defense has to cover lots of grass. On this play, TCU’s pretty committed to stopping the zone handoff, with a nickel cornerback (No. 31) taking away Murray’s keeper option. That leaves a receiver with tons of space to Murray’s left ...

... and Murray, as if just to be rude, hands off anyway. It’s still really tough to stop, especially when you flow away from where the play is hitting:

The play works because two TCU defenders (a linebacker and an end) lose contain.

But don’t ignore the receiver to the top of the screen, who executes his clear-out duty by selling that he’s heading toward the end zone. The corner responsible has to commit and flip his hips, turning his back to the play. That’s how you can stretch a defense vertically without passing, creating space to run into.

That’s the genius of the Riley offense.

We’ll see if that stays true against Alabama. The Tide are No. 8 in Defensive S&P+, 15 spots ahead of the best unit the Sooners have faced so far (TCU) and way ahead of every Big 12 defense except Iowa State. Bama’s game-wrecking defensive tackle, Quinnen Williams, is one of the few players good enough to give problems to OU’s interior linemen.

But for a rare change, the Tide defense enters a game without a guarantee it’s better than the opposing offense.