KANSAS CITY, Mo. — History is written by the victors, and the newly crowned Royals wasted no time. In the jubilant visitors’ clubhouse at Citi Field, the champagne had yet to dry when first-base coach Rusty Kuntz introduced the hidden protagonists of their tale.

The Royals have assembled one of the industry’s most well-respected scouting operations departments. As Kuntz explained, it was through their painstaking efforts that the heroes targeted their foil.

This is how they became convinced that Lucas Duda couldn’t throw.

And in the warm afterglow of clinching the World Series — after Duda’s errant throw sucked the last bit of life from the teetering Mets — the Royals reveled in a scouting report that proved to be prophecy.

“Bless his heart, Duda,” Kuntz told the Kansas City Star not long after that memorable Game 5. “He’s a good bat.”

Five months later, for the first time in the history of baseball, the last two teams standing will be among the first teams swinging. On Sunday night, the Mets will open their 2016 season against the Royals, who will raise their title banner. On Tuesday night, they will hand out their championship rings.

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The Mets say they have moved past their failure to make the most of their magical summer. Their World Series defeat in five games was a collaboration.

Yoenis Cespedes, a picture of power and grace during the season, looked overwhelmed by the game’s grandest stage. Jeurys Familia, a dominant late-game force, set the tone for a rough series by giving up Alex Gordon’s tying home run in Game 1.

Terry Collins, after four decades in the game, again showed that pressure can let a man’s heart get in the way of his head. It was his decision to let Matt Harvey begin the fateful ninth inning of Game 5, in which the Royals scored two runs to tie it and set up their 7-2, 12-inning victory.

But nobody bore more of the brunt than Duda, who in a single pressure-packed instant defined the pleasure and pain that have shaped generations of anguished Mets fans.

“There’s things that all of us can sit here and look at and say we could have done this better, we could have done that better,” captain David Wright said. “It’s not efficient. It does nothing for us now to sit here and try to pick apart this play or that play.”

‘THAT OPINION HAS NO SUBSTANCE’

The Mets’ chances of winning the World Series this season hinge on how they grow after what amounted to a stomach-churning near-miss. But moving forward is an individual matter, not much different from mourning.

For Duda, it took a while. He’s made peace with the throw, never ducking the blame. It was routine, a play he insists he makes nine out of 10 times. He blew it. Yet there still are some scars.

In a clubhouse with no shortage of brash and boisterous personalities, Duda is among the most reserved. He often jokes about his quiet nature, preferring to infuse his comments with what he calls “vanilla.”

But on a quiet morning in spring training, as he looked back at a play that earned him a place in infamy, Duda infused his comments with bluntness.

He was stung by the unflattering shots at his defense.

“I read something from Kuntz, the third-base coach,” Duda said of the Royals’ first-base coach. “He said ‘we’ve got this guy as a DH,’ and again, that’s an opinion. But it’s somebody to me that really doesn’t matter. How many big-league games has that guy played in?”

The answer is that before becoming a well-respected coach, Kuntz played 277 games in parts of seven seasons with three different big-league teams. To Duda, the point still stands.

“That opinion has no substance,” he said. “It’s a guy talking that coaches third base.”

‘JUST SORT OF RUSHED IT’

The lowest moment of Duda’s big-league career began with the Mets ahead 2-1 and two outs away from reviving their hopes and sending the World Series back to Kansas City for Game 6.

Twice in the series, the Mets had surrendered late-game leads, and in this tense ninth inning, they stood on the brink of making it a tortured trifecta.

Eric Hosmer stood on third base, just 90 feet from tying it up and filling Citi Field with a sense of dread. At the plate, Salvador Perez beat Familia’s fastball into the ground.

Duda called it a four- or five-hopper that forced Wright to drift to his left. As he’s done thousands of times, Duda looked for the bag, checked the baserunner, then moved into position to receive the throw. There would be plenty of time.

Plenty of debate has centered on whether Wright’s loopy sidearm throw across the diamond gave Hosmer more precious time to pull off his daring dash for home.

“But there’s nothing that David could have done,” Duda said. “David threw a strike.”

On the bench, the Mets were convinced that Hosmer had broken too late. A good throw to the plate would punch their ticket to Kansas City and the promise of new life.

But the throw sailed high and wide of catcher Travis d’Arnaud, who didn’t come close to backhanding it.

“I kind of hooked it, just sort of rushed it,” Duda said. “That’s really all it was . . . I just made an errant throw.”

‘THAT’S NOT A GOOD PLAY’

Keenly aware that their reactions on the field are constantly being preserved for the record, ballplayers are particularly conscious about keeping their body language in check. But as Duda’s throw sailed past d’Arnaud, the players were betrayed by their emotions.

For a moment, the contorted faces in the Mets’ dugout were indistinguishable from those of the horrified fans behind the screen. A groan could be heard on the bench before the Mets scrambled to collect themselves.

Three innings later, the World Series was over. So began Duda’s long winter as the Royals’ patsy.

As Duda fielded questions at his locker, the Royals spoke of scouting reports that made the first baseman a target to exploit. It’s what ultimately emboldened Hosmer to get aggressive.

Even now, Duda agrees that Hosmer “timed it well.” But as he heard the story rehashed throughout the offseason, the first baseman bristled at the notion that the play somehow was born out of planning, not sheer recklessness.

“Was it a good baserunning play? I don’t think it was,” Duda said. “I threw the ball away and then that play looks good. That’s not a good play right there. You’ve got a few games up. The whole situation, you’re up by a few games, you can be a little more aggressive. But a good throw gets him. I owned up to it. I didn’t make the throw.”

‘IT’S NOT GOING TO DEFINE MY CAREER’

Scouting rarely generates unanimous opinions. Duda’s throw is no exception. One rival scout said that he, too, had spotted a potential weakness. But another scoffed at that evaluation, mimicking some of the sentiment that lingers within the Mets.

It doesn’t matter now, of course. The story will forever be written by the Royals. They are the world champions. They earned that right.

“He gave it to me pretty good,” Duda said, once again seizing upon Kuntz’s comments. “It’s his opinion, man. If he thinks I’m a [expletive] first baseman, then it’s OK.”

In his career, Duda has committed three throwing errors at first base. But there is no disputing that he sailed the most important throw of his life and then spent the winter trying to get over it.

“It’s just a process, but it did hurt for sure,” Duda said. “Did it cost us the game? I mean, who knows how it would have ended up?”

A new season brings a new opportunity to write history. The Mets hope to seize that chance. If they do, the slugging Duda figures to play a prominent role.

“I’ve told him once, I’ve told him a million times, that’s not all what’s going to define you,” Wright said. “What defines you is you being a big reason that we got to that point, another big reason why you’re going to get us back to that point. He’s one of the reasons that we made it that far and he’s got to remember that.”

Mostly, Duda hopes for a chance at redemption.

“That’s one of those things that I think can break you or propel you,” he said. “It’s not going to define my career. It’s not going to break me. I’m going to become stronger.”