Jalen Green, from Nowhere, USA, to the top of the NBA draft

BY THE AGE of 15, there were few places in the basketball world Jalen Green could go and retain some level of anonymity.

Green's highlight tapes had become the stuff of internet legend. He'd been ranked the No. 1 player in the high school Class of 2020 before he ever played in a high school game. Documentary filmmakers had been following him and his family for years.

But when Green walked into the UCLA men's gym in the summer of 2017, trying to earn his way onto the main court for the legendary summer hoops run, only a few people knew who he was.

"I didn't know him from a can of paint," said former UCLA star Rico Hines, who helps organize the games each summer. "Everyone and their momma always texts me about different cats, telling me to bring them out."

Hines had invited Green to drive down from his hometown in California's Central Valley on the recommendation of a mutual friend, but made no promises about how much run he'd get with the NBA players, including Kevin Durant, who were scheduled that day.

"I remember Brandon Jennings was there that day. He knew who [Green] was," Hines said. "But Brandon was like, 'You might be the No. 1 player in the country but you gotta prove it in here.' It wasn't like trash talk. It was like, 'Let's see it.'"

Green waited and waited on the sidelines as the pros played on what Hines called "the winners court." Sometimes he'd jump into games on the two other courts, known as the "losers court" and the "losers' losers court."

It took hours for him to get a chance to play in the featured game. Finally, when one of the pros was done for the day and ready to tap out, Hines looked over at Green and pointed for him to go in the game and guard Durant.

"I mean, at first you could tell he was kind of, 'Damn, I'm on the court with KD,'" said former Houston Rocket Bobby Brown, who is a regular at the UCLA game. "I'm pretty sure KD scored on him a few times at first. But then he got out on a fast break ..."

The dunk that Green unleashed is on tape somewhere, but Brown will never forget it.

"I'm sure it was a regular dunk for him," Brown said. "But everybody in the gym just looked at each other like, 'Ooooooh, s---!'"

Brown was one of the only people in the gym that day who knew of Green and his reputation for highlight-reel dunks from social media. But after that day, there were a lot more believers. "A lot of guys have had their coming-out parties in that gym," Hines said of the famous summertime hoops haven, which has been a favorite of L.A.-based stars like Marquess Johnson, Baron Davis, Kobe Bryant, Russell Westbrook and Magic Johnson.

"It's where reputations are made. But you have to earn your spot. And Jalen definitely did that day."

MOST FUTURE SUPERSTARS have origin stories like this in their past. A few key moments where their enormous potential is revealed to themselves or the rest of the world, and everything that comes afterward is about living up to it.

Green, who turned 19 on Feb. 9, has continued to build off that star turn in the UCLA gym three summers ago. But it'll take a decade or so to know if he lives up to the promise of his talent. He has been compared to younger versions of Kobe Bryant and Tracy McGrady, called a cross between Zach LaVine (athleticism) and Bradley Beal (shooting), and been featured in several documentaries, including one called "Prodigy" on Quibi.