You know the old theory about how a butterfly flapping its wings in New Mexico can, through chaos theory, help lead to a hurricane in China?

In this case, the butterfly was in Milwaukee.

And the hurricane was felt in New York City. Both sides of the Brooklyn Bridge, in fact.

It was on Nov. 16 when the NBA’s trade moratorium was lifted, and almost immediately it seemed like the Milwaukee Bucks had done everything possible to clinch the 2021 NBA title. They acquired New Orleans’ Jrue Holliday in a four-team deal. And they acquired the Kings’ Bogdan Bogdanovic in a sign-and-trade.

The Bucks, who had recently convinced Giannis Antetokounmpo to extend his contract, looked set up for years to come with a powerful, potent and diverse lineup.

Except it turned out the Bucks and Kings had jumped the gun on the Bogdanovic trade, violating the league’s tampering rules. Bogdanovic signed a free-agent deal with the Hawks instead. Donte DiVincenzo stayed with the Bucks and did have a nice season as a role player before going down with a season-ending injury.

That’s all to Milwaukee’s eternal regret.

But it was a sliding-glass moment that also affected both of New York’s basketball teams, ultimately. Maybe Bogdanovic wouldn’t have helped the hapless Bucks these first two games from looking like a disjointed AAU team, but he almost certainly would’ve allowed them to win the necessary amount of games to either bypass the Nets entirely in the Eastern semifinals or, at the least, secure home-court advantage.

And if that were the case, the Nets’ elimination of the Bucks wouldn’t be the foregone conclusion that seemed to exist on Thursday, hours before the teams would tip Game 3 of the series back in Milwaukee, the Bucks desperately clinging to their season.

With Bogdanovic, and with the teamwide health the Bucks have mostly enjoyed this season, the Bucks would undoubtedly make a better go of this matchup than they have at the least, and would more than likely be a slight favorite.

So bully for the Nets.

But the Bucks’ November folly – for which they were ultimately penalized a second-round draft pick – was as detrimental to the Knicks, as it turns out, as it was helpful to the Nets.

For while most of the haunting memories Knicks fans will attach to the one-sided, five-game whitewash against Atlanta in the first round will come courtesy of Trae Young, Bogdanovic turned out to be every bit as much of a nuisance.

In Game 1, after all, he hit what might well have been the biggest shot of the series, in what almost certainly was its turning point. With the Knicks holding a 103-100 lead and under a minute to go, there was a pinball-like ricocheting of the basketball from hand to hand, primarily RJ Barrett’s. But Barrett couldn’t secure the ball and it bounced directly to Bogdanovic in the corner, who drilled it.

The Hawks never trailed again in that 107-105 win, and never looked back again after stealing Game 1 at the Garden.

“We did almost everything right on that play except for one thing,” Knicks coach Tom Thibodeau lamented later. “Credit to Bogdanovich. He wound up with the ball in his hands and made the shot and it was a dagger for us.”

For the series, Bogdanovich averaged 14.4 points, second only to Trae Young, and hit on 33 percent of his 3s. If Young was the prime culprit in ending the Knicks’ season prematurely, Bogdanovic was an un-indicted co-conspirator. And if things had gone according to the original plan, he wouldn’t have been anywhere near Atlanta or Manhattan torturing the Knicks.

He’d have been in Milwaukee waiting to torture – and torch – the Nets, as a member of the Bucks. The butterfly in Milwaukee turned two basketball seasons upside down in New York City. One for the better. One for the worse. Crazy sliding doors.