To move up high enough, Dallas ultimately had to persuade the Atlanta Hawks to surrender the No. 3 overall pick. It cost Dallas both the No. 5 pick, which Atlanta used to take Trae Young, as well as the Mavericks’ top pick in the 2019 draft.

But the Dallas owner, Mark Cuban, blessed the deal, even at that price, because Nelson lobbied so hard for it. Five years earlier, during the 2013 draft, Nelson and his longtime international scout, Tony Ronzone, pushed for the Mavericks to use the No. 13 pick on a little-known Greek teenager named Giannis Antetokounmpo. Cuban wouldn’t allow it, given that Antetokounmpo, unlike Doncic, was mostly a mystery — and promptly regretted it as Antetokounmpo blossomed into a star in Milwaukee.

So this time, after the disappointment of the lottery, Cuban blessed Nelson to do whatever it took to land Doncic. What the team got was the son of a former Slovene pro — Sasa Doncic — and a veteran of three full seasons in the EuroLeague and Spain’s La Liga with Real Madrid after Luka Doncic made his pro debut at 16.

To the Mavericks’ delight, Doncic was more N.B.A.-ready than they ever dreamed — as his 16-for-29 shooting in the final three minutes of one-possession games this season would suggest. As Carlisle put it: “Unique background, unique skill set, unique body type.”

“I hesitate to throw out names like LeBron James and Magic Johnson, who have been do-everything kind of stars, but it’s pretty clear now that Luka has many of those same traits and has proven that he can do a lot of those things,” Carlisle said. “He has deceptive size, strength and quickness — and an understanding beyond his years on how to use his body to make plays and draw fouls.”

Carlisle is hardly alone in making such lofty comparisons. Miami’s Dwyane Wade, one of the league’s foremost James experts after their four seasons together with the Heat, has called Doncic’s passing “LeBron-like.”

Los Angeles Clippers Coach Doc Rivers said of Doncic: “He’s my favorite player to watch almost, and not talking just rookies. First of all, he plays with a great joy — I love that. And he’s just so advanced in the way he plays. The sky’s the limit for him. Wait until he gets in shape.”