Andy Reid admits Chris Berman sent him the play that the Chiefs used to surprise the Broncos

The Kansas City Chiefs spent much of Monday night showing what their offense could look like with a new feature back. One of their most memorable touchdowns, though, came from a play that was anything but new.

Late in a 31-10 win over the Denver Broncos , Patrick Mahomes lined up with backup quarterback Justin Fields beside him and helped sell a sequence that looked designed to go in several different directions.

Fields moved left as if he might take the ball. Mahomes instead flipped a short forward pass to Kenneth Walker III, who crossed the formation and finished the 2-yard touchdown.

The play had all the hallmarks of an Andy Reid special with the Chief's head coach later revealing the source.

“Chris Berman sent me that play, so that’s a 1936’er right there,” Reid told reporters Tuesday. “Honestly, it was a great play. They executed it well. … We’ve run it before, just not that smooth.”

Walker had to learn play from ancient film

The age of the concept apparently made preparing for it an experience in itself.

Walker joked after the game that Kansas City’s film study hardly resembled the high-definition footage NFL players are accustomed to seeing.

“The film we watched was probably from 1900, so it was hard to see,” Walker said. “But we worked it over and over in practice, and we felt like that was going to work... and it did.”

That touchdown capped a remarkable Chiefs debut for Walker . The former Seattle Seahawks running back finished with 173 rushing yards and 191 yards from scrimmage, both career highs, while scoring twice.

His biggest play came on a 60-yard touchdown run after he recognized Denver crashing inside.

“I knew they were going to crash in, so when they crashed in, I just bounced it out,” Walker said. “I was one-on-one with the corner, I outran him and it was off to the races from there.”

Walker changed shape of Kansas City offense

Mahomes has spent much of his career carrying a Chiefs attack that rarely leaned heavily on the running game. Walker’s arrival may alter that equation.

“I told you all, literally, like first press conference,” Mahomes said. “Y'all were asking, what's the difference with our offense? And I said, K9. Like, it's just that simple.”

Walker forced 14 missed tackles and produced 101 rushing yards over expectation, according to NFL Pro, giving Kansas City exactly the kind of explosive ground threat it has often lacked.

Reid described his performance as “spectacular.” The Chiefs may not need a trick play from 1936 every week. But after Berman ’s suggestion helped produce a touchdown, Reid might not mind receiving another history lesson.