Last April, Kevin Durant, of the Oklahoma City Thunder, held a playoff postgame press conference in a blue long-sleeved shirt with tiny screen-window checks. It had a spread collar and was buttoned up to his neck. Durant’s attire was noteworthy for several reasons, the first of which was that for most people it wasn’t noteworthy at all. Once upon a time, NBA press conferences were no different from the press conferences of other sports. An athlete looked like he threw on whatever was handy, answered reporters’ questions, then went on with his night. Durant is a good example of how that’s changed: He also likes to meet the press wearing a backpack.

For the people who notice this sort of thing — and it must be said that the backpack is something you’re meant to notice — the change Durant encapsulates is both surreal and ironic. The bag is never removed, worn with the safety strap fastened, and rarely acknowledged, as if the affect is actually just natural, as if Durant might be carrying actual homework. In the same way that there are people who never thought they’d see a black American president, there are also people who never thought they’d see a black basketball star dressed like a nerd.

Durant isn’t alone. In their tandem press conferences, LeBron James and Dwyane Wade, of the Miami Heat, alternate impeccably tailored suits with cardigans over shirts and ties. They wear gingham and plaid and velvet, bow ties and sweater vests, suspenders, and thick black glasses they don’t need. Their colors conflict. Their patterns clash. Clothes that once stood as an open invitation to bullies looking for something to hang on the back of a bathroom door are what James now wears to rap alongside Lil Wayne. Clothes that once signified whiteness, squareness, suburbanness, sissyness, in the minds of some NBA players no longer do.

If you happen to be someone who looks at Durant, James, or Amar’e Stoudemire’s Foot Locker commercials — in which he stalks along a perilously lit basketball court wearing a letterman’s cardigan, a skinny tie, and giant black glasses (his are prescription) — and wonders how the NBA got this way, how it turned into Happy Days, you’re really wondering the same thing about the rest of mainstream black culture. When did everything turn upside down? Who relaxed the rules? Is it really safe to look likeCarlton Banks?

It certainly appears that way.

Carlton Banks wore his polo shirts, khaki pants, and cardigans tighter than a young black kid would dare in 1990-anything. The joke was that he and his two sisters were culturally white, and the secret of Carlton is that he began to see himself the way both his hip-hop cousin, Will, and the show saw him; and as he began to gain a black consciousness (like when he discovered Public Enemy), he gradually came to resent the laughter.

Carlton was something new for TV. The Huxtables of The Cosby Show were upper-middle class. The Bankses were rich. And Americans weren’t used to seeing rich black kids, which is why we were asked to watch The Fresh Prince through the eyes of a poor black one, and, in his discombobulation, Will saw in the Bankses what an indigent black kid from West Philly might: cartoons. Turning Carlton and Hilary into jokes made success look silly. The story of black men on television in the 1980s was always lightly Dickensian — upward mobility in the hot air balloon of rich white guilt: Benson, Webster, Arnold, Willis.The Fresh Prince was the same formula but with intraracial chafing.

All the interesting comic tension of the show was in how long it would take until Will got Carlton to do something black. How long until he, say, wore a track suit or stopped dancing like Belinda Carlisle and started doing the running man. This, of course, is also what people spent Sammy Davis Jr.’s entire career hoping they’d see, that he’d replace the skin he’d seemed to shed, that he would change back. The tragedy of Davis is the triumph of Carlton: Neither did. You know who changed on The Fresh Prince of Bel-Air? Will. Carlton got Will educated, enlightened, prep-schooled, and blazered. It’s only a mild overstatement to say that Carlton changed us, too.

There were other black nerds — the Derwin of De La Soul’s first album, the Poindexter mentioned in Young MC’s “Bust a Move,” Steve Urkel, Spike Lee’s Mars Blackmon — but Carlton was the most pernicious because he was with us the longest. At its best the Carlton character embodied things that gave some black people pause — enthusiasm, knowledge, diction, all that’s symbolized by a sweater wrapped around your shoulders. If you saw a little of yourself in Carlton or a schoolmate saw a little Carlton in you, you probably felt unlucky, since being a Carlton became synonymous with aspirational whiteness and selling out.

What’s most surreal about what LeBron James and Dwyane Wade are wearing is that the clothes are versions of what, in the late 1980s, 1990s, and early 2000s, got kids terrorized. Black youth culture was so steeped in hip-hop and monolithic ideas of what and who black people should and should not be that in order to incorporate a tie into your daily wardrobe, you had to walk a kangaroo court of Karl Kani hoodies and FUBU jeans. Black love once seemed more conditional than it does now. In 1991, Kanye West might have been too much of a weirdo to be a star.

But 21st-century blackness has lost its rigid center, and irony permeates the cultural membrane. More than kids knowing they can be president of the United States, it might be more crucial to the expansion of black identity that — thanks to, say, N.E.R.D or Odd Future — they know they can be skate punks. Kanye West can release an album called The College Dropout, then run around the world dressed like an Oberlin junior. (The backpack craze was popularized by him.) West had done what 15 years of The Fresh Prince of Bel-Air and Family Matters could not. He ushered in the chic of the black nerd. He cleared a safe space for narcissism and self-deconstruction; for singing rappers with names like Drake, J. Cole, and Tyler, The Creator; for the Roots to be Jimmy Fallon’s house band; for the threat in the music to move from the street to the psyche. Hip-hop had already begun to splinter into a land of a million mixtapes before West’s arrival. And with that shattering, black male style was transitioning away from Sean Combs’ “Puffy” era gilded age, with its plushness, flamboyance, glamour, and actionable danger.

If you were black, liked hip-hop, but also liked the confessional dimensions of the singer-songwriter, West was an alternative you could relate to, and you could see the change in NBA press conferences. Once upon a time — about two or three years ago — these same players greeted the press and stepped onto buses awash in big, creamy sweaters, roomy leather jackets, and substantially karated wristwear. Then, suddenly, that was switched for less urban, more meticulously groomed style. You can still find baggy denim shorts, long white T-shirts, sideways baseball caps, and platinum ropes with a diamond-encrusted crucifix. But it’s Allen Iverson in the time of Blake Griffin, Gucci Mane in the moment of Drake. These men aren’t dressing for A-T-L pool parties. But they’re not wearing the clothes of the streets, either. Durant and James and Stoudemire are wearing what black kids are wearing in the suburbs, where white kids’ belief that the racial grass is greener applies to black kids.

If there were a tagline for the change, it would have come from Jay-Z’s melodic admonition “Change Clothes”: “Y’all niggas acting way too tough / Throw a suit and get it tapered up.” So the big stars arrived at press conferences looking like the executive Jay-Z suspended his rap career to become, looking, well, like the president of the United States.

In a sense, the shift is also a snapshot of how stylists continue to remove Darwinism from sports style. There’s very little natural selection now. And yet, no matter who dressed him, it’s fun to see Amar’e Stoudemire, in those Foot Locker ads, walking past NBA aspirants as some kind of instructor, like he’s the Tim Gunn or RuPaul of the NBA. The cardigans and black frames, the backpacks and everything else: It’s all as overdetermined as what happens on Project Runway with Lady Gaga and Nicki Minaj, and with the drag queens. “Nerd” is a kind of drag in which ballers are liberated to pretend to be someone else.

When David Stern imposed the league’s reductive dress code six years ago, all this role-playing, reinvention, and experimentation didn’t seem a likely outcome. We all feared Today’s Man. But the players — and the stylists — were being challenged to think creatively about dismantling Stern’s black-male stereotyping. The upside of all this intentionality is that these guys are trying stuff out to see what works. Which can be exciting. No sport has undergone such a radical shift of self-expression and self-understanding, wearing the clothes of both the boys it once mocked and the men it desires to be.

It’s not a complete transformation. Being Carlton wasn’t just code for nerd, it was code for gay, and the homophobia these clothes provoked still persists, even from their wearers. Once last year, Dwight Howard, of the Orlando Magic, wore a blue-and-black cardigan over a whitish tie and pink shirt to a press conference. When a male reporter told him it was a good color on him, instead of asking the reporter “Which color?,” Howard spent many seconds performing disgusted disbelief: Whoa, whoa. A moment like that demonstrated how hopelessly superficial all this style can be. The sport can change its clothes, but, even with Dan Savage looking over its shoulder, will it ever change its attitude? If Howard thinks compliments about his cardigan are gay, he probably shouldn’t wear one.

Still, something’s changed in a sport that used to be afraid of any deviations from normal. That fear allowed Dennis Rodman to thrive. Now Rodman just seems like a severe side effect of the league’s black-male monoculture. The Los Angeles Lakers officially recognize the man who was involved in one of the most notorious fights in sports history as “Metta World Peace.” Baron Davis, of the Cleveland Cavaliers, spent the summer in a lockout beard that made him look like a Fort Greene lumberjack. And Kevin Durant wears a safety-strapped backpack. If Stern was hoping to restore a sense of normalcy to the NBA, he only exploded it. There no longer is a normal.