PITTSBURGH — DJ Burns Jr. is holding court again. NC State’s gregarious giant with the gap-toothed grin is swarmed by reporters near his locker the day before an improbable appearance in the second round of the NCAA Tournament against Oakland. He is marveling at what an incredible stage he’s just stampeded onto. “That’s the beautiful thing about March Madness,” he says. “If there’s something interesting, they’re going to find it at this time of year.” Now is when previously undiscovered stars and compelling storylines get introduced to a national audience, in other words.