KANSAS CITY, Mo. — Through one of the most dominant stretches in NFL history, the most steadfast lifeline for the Chiefs has been the prolific and uncanny connection between Patrick Mahomes and Travis Kelce. With all due respect to Kelce’s fiancee Taylor Swift, they’re the dynamic duo around here.

The catalogue of jaw-dropping moments between them is too vast to even approximate a list. But suffice to say it can be encapsulated through such glimpses as a span of 28 completions in 28 targets a few years ago and the ol’ mic’d up telepathy breakdown in the 2019 AFC divisional round win over Houston.

“I don’t understand how you know what I’m doing …” Kelce said after one play.

To which Mahomes a moment later said, “That’s what I wanted you to do.”

If only it were still so constant and seemingly simple.

But while Kelce’s swivel-hipped burst diminished last season, he still had 97 catches for 823 yards and a vintage performance in another AFC divisional round win over Houston, with seven catches for 117 yards and a touchdown.

And as much as his production in the next two playoff games made you wonder how much he had left to give with one year left on his contract and his 36th birthday looming in October, Kelce through apparent rigorous training lost weight in the offseason and has enjoyed a few fine moments this season.

More memorably and pivotally, though, he’s also had a couple jarring misplays — including, alas, the swing play of a 20-17 loss Sunday to the visiting Philadelphia Eagles.

In what could only be considered a statement game after the Eagles dismantled the Chiefs, 40-22, in Super Bowl LIX — and the Chiefs began this season with a dud 27-21 loss to the Chargers in Brazil — they were on the move to restore some order early in the fourth quarter before the brutal twist.

On second-and-goal from the 6-yard-line and the Chiefs trailing 13-10, Mahomes fired to Kelce cutting into the middle at about the 2, with his momentum seemingly set to carry him into the end zone.

But the ball ricocheted off Kelce’s hands and was intercepted by Andrew Mukuba, who returned it 41 yards — and likely would have taken it all the way if 6-5, 310-pound offensive tackle Josh Simmons hadn’t somehow summoned an 18.35-mph gear and run him down.

Ten plays later, though, the Eagles rendered that a moot point by turning that reversal into a Jalen Hurts Tush Push TD and taking a 20-10 lead with 7 minutes, 48 seconds to go.

No one play wins or loses a game, to be sure. And it’s of ample note that Harrison Butker missed a 58-yard field-goal attempt and that the offense overall is grappling to get any rhythm or traction. Etc.

But Kelce’s gaffe looms large over this on several levels.

It’s at least a microcosm of the Chiefs issues in the first three-game losing streak of the Mahomes Era, and their first 0-2 start since 2014, that the connection that’s been the greatest constant of this time suddenly seems more volatile than inevitable.

And Kelce only further contributes to that notion with his fuming on the sidelines and antics like going at teammate Jawaan Taylor last week, stuff that’s reminiscent of rash behavior early in his career, while not demonstrating the accountability of speaking postgame with the media.

Which matters because it’s an immediate conduit to Chiefs fans and a standard he should be trying to impress upon the teammates he’s in such a position to influence.

In the void Kelce left, Mahomes tried to absorb some blame by saying he thought he “threw it just a tad too early.” And that if he put it “more on his body and not so far out in front of him,” Kelce could have caught it more easily and scored.

No doubt you’ll get to hear all about it from Kelce’s perspective on his “New Heights” podcast later this week. Just like last week after the loss in Sao Paulo.

As usual, Kelce didn’t speak after that game, either. But on the podcast with his brother, he said he was taking “accountability myself” for not being ready on the first drive — and thus crunching Xavier Worthy in the collision that left Worthy with a shoulder injury that knocked him out of that game and kept him out Sunday, too.

Kelce has had an amazing career. He’s on his way to the Pro Football Hall of Fame, likely first ballot, and I believe he’s still got the juice for more yet. The return of Worthy and the suspended Rashee Rice in the weeks to come figure to boost his opportunities, too.

He had that 37-yard touchdown catch against the Chargers, after all. On Sunday, he had four catches for 61 yards — highlighted by a fourth-and-4 catch for 18 to help set up a 13-yard touchdown run by Mahomes.

But as the Chiefs continue to look somewhere between mortal and vulnerable since reaching five of the last six Super Bowls, Kelce’s day in some ways epitomizes that.

The reason the Chiefs won an NFL-record 17 straight one-score games, including 11 last season, wasn’t just because they found a way at the end or a quirk of fate fell their way.

It very much was because they kept making plays to be in that position by game’s end.

Exactly the opposite of what’s happened in losing two one-score games to start this season; each was marked by turns that had them two scores down into the middle of the fourth quarter and ultimately just on the outside looking in as time ran down.

The most blatant of those on Sunday was Kelce converting a great opportunity into a play that boomeranged the other way.

Look, this season has barely started, and the Chiefs have plenty of time to right their early issues. But it’s also true that history says that only 35 of the 288 teams to start 0-2 since 1990 have reached the postseason.

So it’s natural to wonder how much gravity is starting to finally pull the Chiefs back down to Earth — and how much that might be embodied in the twilight of a career long marked by such remarkable dependability.

Early as it might be, that’s a premise that will hover over this season until proven otherwise.