With a 500-kilowatt smile hiding that angry boulder on his shoulder, J.K. Dobbins rumbles through the NFL on a revenge tour fueled by a secret.

“The dream is to get a ring,” Dobbins declared late Sunday afternoon, after he ran for 111 yards and Denver did Dallas dirty, by the wicked score of 44-24.

When the circle of television cameras around him in the Broncos locker room dissipated, however, Dobbins let me in on a little secret that motivates him every time he carries the rock.

Unsure where he stood among the league leaders in rushing, I informed Dobbins he had moved up to third place, behind only Jonathan Taylor of Indianapolis and Buffalo’s James Cook, with 634 yards on the ground.

“That’s all right,” Dobbins told me as he fetched a backpack from his locker stall. “But I want to be No. 1.”

Dobbins doesn’t care if your name is Saquon Barkley or Derrick Henry.

He’s gunning for your crown, out to prove there’s not a running back in the league better than a guy who was disrespected by the L.A. Chargers during the offseason, forcing him to sign with Denver as a free agent for a bargain-basement salary of $2.75 million plus incentives.

“I do know,” Dobbins said, “a lot of people didn’t think I was going to be that good, to be honest.”

Now you know why that’s not a chip on his shoulder, but a boulder.

“I’m proving myself right, that I made the right decision coming (to Denver),” said Dobbins, whose previous five pro seasons flashed undeniable brilliance wrapped around two devastating injuries that tried but failed to ruin his determination to be great.

This is the first Denver team since the Super Bowl 50 champs that not only dreams big, but isn’t afraid to give a voice to out-sized ambition.

And nobody personifies that sweet swagger better than Dobbins.

While Bo Nix is a fearless young QB and cornerback Pat Surtain II locks down every piece of earth not covered by water, the player who has instilled the Broncos with a killer smile and a fresh new vibe is Dobbins.

With all due respect to edge-rusher extraordinaire Nik Bonitto, the joy of the hunt that Dobbins carries from the practice field to the huddle makes him the most powerful catalyst of this team’s promising 6-2 start, which has Denver standing atop the AFC West standings.

Let’s give a tip of the cap to general manager George Paton, who infused the Broncos with a nasty edge often missing until the additions of Dobbins and safety Talanoa Hufanga in the offseason.

“He’s done exactly what J.K. does, and that’s running very physical, very tough,” Nix said.

Nix, however, might be even more impressed with how Dobbins is willing to “stick his face in there” when blocking against a blitzer, as he did on a touchdown pass to Troy Franklin.

Offering Dobbins the ultimate compliment to a workhorse, Nix said: “Not a prima donna.”

While rookie back RJ Harvey had a breakout performance by scoring three  TDs against Dallas, it’s Dobbins who has made good on coach Sean Payton’s vow to bring a sledgehammer to his playsheet.

Administering a Big D beatdown was particularly sweet for Dobbins, because he was born deep in the heart of Texas 26 years ago.

“My grandparents are Cowboys fans,” said Dobbins, who blocked his beloved relatives from his cellphone heading into the game against Dallas.

But after this sweet Denver victory, he vowed to ring gramps and grandma to tease: How ‘bout dem Cowboys?

“Maybe I was born to be a Bronco,” said Dobbins, laughing. “It just took a little time to get here. I had to get over the mountains.” 

A storyline repeated so many times in the days prior to the game that Dobbins had to hear how the Broncos made a mistake in letting running back Javonte Williams get away to the Cowboys.

Williams entered the contest as the NFL’s No. 2 rusher. But after getting orange crushed, he now trails Dobbins 634-633.

I did the math. Double-check it for me, would you?

Dobbins is on pace to rush for 1,347 yards. 

That makes him a real threat to become the first Denver back to rank in the league’s top five in rushing since 2003, when Clinton Portis ran for 1,591 yards, but drove coach Mike Shanahan crazy with his flashy Super Fly fashion sense after he tossed his orange uniform in the laundry on Sunday afternoons.

“Since 2003? Woo, that’s a long time,” Dobbins said. “I’m going to try to keep going. Try to get it done.” 

There aren’t many advantages to being as old as me, so I was happy to educate Dobbins on a little Broncos history, spilling the tea on the blockbuster trade that sent Portis to Washington and brought future Hall of Famer Champ Bailey to Colorado in 2004.

“Oh, I remember Clinton Portis,” said Dobbins, digging deep into his childhood memories, “as a running back for the Redskins.”

We’ll forgive Dobbins for having no recollection of C.P. toting the rock for Denver, or reading all about how the Broncos stole Bailey from Washington.

Because back when that monster trade went down, Dobbins was just getting ready to enter the first grade.

Time flies.

Dobbins rumbles.

He’s the best thing to happen to the Denver rushing attack in more than 20 years.

Dobbins is the real MVP of this team.