When Boston Celtics forward Grant Williams was growing up, he played a game only a mother could love; his father and brothers sure didn't. Williams was indisputably the leader of the basketball team at Providence Day School in Charlotte, North Carolina, but he "was never the guy that wanted to score 40," his brother Gabon said. "We had to scream at him to do that."

Gabon, who played at West Charlotte High and then Johnson C. Smith University, saw him sharing the ball, playing defense, "you know, being a team player," and didn't think scouts would be impressed. Gabon told him that he would not stand out if he wasn't scoring at a high level and dunking on everybody.

"He did not like my philosophy," Gabon said.

Williams, the youngest of five brothers, told him that wasn't his style. He wanted his teammates to get touches, build up their confidence and play together. That way, against teams with stars solely focused on scoring, his team would have an edge.

"My dad and my brother, all those guys, they felt like scoring would get you where you need to be," Williams said. "And my whole thought process is, like, there's guys who are paid a lot of money to score who are way more talented than me at scoring the ball, at the time especially. So I was like, I need to be able to do all the little things first before I can expand my game and be the guy that's a dominant scorer."

Williams' philosophy, he said, has always been about making the right play. He wants to do whatever he can to help the "team culture" and "create a winning environment." He wants to foster the kind of energy on the court that you can only feel when all five players are engaged, enjoying themselves and playing as if their hair is on fire. His family preached selflessness in life, even if they didn't always agree with the way he embodied it on the court, where he believes it is contagious.

In a way that is unusual, bordering on unbelievable for a young player, Williams sounds like he has it all figured out -- and has for some time. Providence Day coach Brian Field remembered Williams joining him in his office at lunch, chatting about basketball, life, whatever he'd just learned in history class. "It seems too good to be true," Field said. In pre-draft interviews last spring, Williams could sense potential employers' apprehension.

"Definitely there were some teams that were really trying to see if the hype was real and seeing if I was actually a genuine person or if it was all a front," Williams said.

There were times, Field said, because of the way Williams carried himself, that the coach had to remind himself he was just 14. When Providence Day added talent in Williams' senior season, he willingly took fewer shots and averaged fewer points than he did as a junior and was rewarded with a state title.

Kevin Ligon, his coach with the AAU team MB1, said Williams was like an assistant coach, making suggestions on the sideline. "Everything he said made sense," Ligon said. In the fourth quarter of a close game, Ligon told Williams, who had been getting a breather, to check back in. "Nah, coach," Williams replied. He thought that Ricky Gouety should stay on the court despite making a couple of mistakes. MB1 went on to win, thanks in part to Goeuty's late-game performance.

"The happiest person on the court wasn't Ricky," Ligon said. "It was Grant. He went and hugged him and I said, 'Coach Grant, once again, you made a good call.' He said, 'I just know how it feels to finally get a chance to get in a game when you've been waiting to play and you kind of just get your legs up under you. He was getting in the groove and I just kinda knew and could feel that for him.'"

As the 2019 NCAA Tournament approached, Tennessee assistant coach Desmond Oliver noticed that Williams was deferring more than usual at the beginning of games. Oliver told Williams that the Volunteers were getting off to slow starts because he wasn't looking to shoot.

"And he stopped me," Oliver said. "He says, 'Coach, I know. But, man, I gotta get my guys going, my teammates. I feel like, all year, I've kind of been the go-to guy and I don't think we can win the whole thing if everyone knows that I'm going to get the ball and expects me to take 25 shots.'"

Field and Ligon independently cited how long they have been in the business -- 22 and 30 years, respectively -- when saying they've never met a kid like him. Oliver repeatedly called him a "different cat."

"There will be more talented guys coming through Knoxville," Oliver said. "There's always more good players out there. But no one is going to ever come through, we don't think again or any time soon, that is that well-rounded as an individual academically, socially, and has all the ingredients to lead and win a basketball game for you."

At Madison Square Garden in October, Brad Stevens sounded like the coaches who came before him in singing Williams' praises. "He's a really good person," Stevens said. "He's smart. He is curious. But he has a basketball savvy that's really high." Stevens praised him for seamlessly switching between different pick-and-roll coverages and defensive assignments the night before against the Toronto Raptors, saying it was difficult at any age and particularly impressive "at 21 or 22 or whatever he is." Williams is 20.

Admiral Schofield, the Washington Wizards forward who teamed with Williams at Tennessee, was not surprised to learn NBC Sports Boston had published a story about Williams' plus-minus after four summer league games and a single preseason game. In another sign that the Tao of Grant had caught on at the professional level, a few minutes into Williams' first stint against Toronto, Raptors color commentator Jack Armstrong shouted, "That guy has set about eight screens already!" In the Land of Tommy Points, the Celtics could not have used the No. 22 pick on a more perfect player.

Boston has the best defense in the NBA, per Cleaning The Glass, and it has held opponents to 95.6 points per 100 possessions with Williams on the court, but no player in the league does more helpful things while posting less impressive individual numbers. He is averaging just 2.4 points and 2.4 rebounds and has shot 12 for 46 (26.1 percent) through 15 games, and yet the Celtics have a plus-8.0 net rating when he's in the game.

Marcus Smart, Mr. Winning Plays himself, said he loves every aspect of Williams' game: how he contributes without touching the ball, how he takes charges, how he always seems to be in the right spot.

"He thinks like me," Smart said. "He reminds me a lot of me when I came in the league my first year. Just putting my imprint on the game in different ways and making myself so valuable where it's hard to take me off the court because I can do so many things to help the team. And that's Grant."

In Phoenix last Monday, Williams came off the bench halfway through the second quarter and Boston immediately went on a 21-4 run, during which he violently rejected the Suns' Kelly Oubre and Frank Kaminsky. In the third quarter, the 6-foot-6, 236-pound forward flung himself to the floor and got tied up with Aron Baynes, a 6-10, 260-pound center. When he refused to let go of the ball, Baynes picked him up and the two of them laughed.

"That's the Grant experience," Ryan Hebert, also known as @Riffs_Man, the preeminent voice of "Weird Celtics Twitter" and perhaps Williams' most vocal supporter on the internet, wrote in a direct message. Hebert's favorite thing about Williams is his demeanor, "the balance of how he plays hard and intense but always seems to be having fun." The Baynes play is an example of what Boston rookie guard Tremont Waters, inadvertently channeling David Foster Wallace, has termed Grant Moments.

"The goofy character is always going to be there," Williams said. "You'll see me on the court, I'll go from being the guy that takes charges, gets rebounds, and five seconds later is laughing with a player. And you're just like, 'How did he do that?' I don't know. I couldn't tell you. It's something I enjoy."

Langston Wertz, a mentor and a sportswriter for the Charlotte Observer, first saw Williams play at eight years old. Vince King, who ran The First Tee of Charlotte, had called Ed Addie, the coach of the Queen City Athletic Association AAU team, to say he had "the biggest kid in the world over here playing golf, and he tells me he plays piano and the violin but he should be playing basketball," according to Wertz. Williams joined the QCAA program and met Addie and Wertz in the gym every Sunday morning.

"He was kind of roly-poly back then, he was real heavy, had never really played basketball," Wertz said, but he somehow had "great hands." Gabon thinks the soft hands were a result of the time he'd spent playing piano, and he got the work ethic from his mother, Teresa Johnson, an engineer who has worked for NASA for more than 30 years.

Williams didn't expect much of himself at first. He liked basketball, but had all sorts of other pursuits. Golf was a family activity, as was tennis, although that was "our least favorite one," his brother Gilbert said. They also gave football a try, "for like a quick minute." Their grandfather, Otto Johnson, got Williams and his brothers into chess and music. When he won a match at a chess tournament, he yelled in jubilation as he reported the victory to the scorekeeper, to the consternation of others in the room.

"Everybody looked at him, man," Gabon said. "Come on, man. You see a little black kid screaming 'cause he just won a chess match. Like, there's not many black kids in the chess tournament, right? Like, come on, man. And then he's screaming. We're like, 'Aw, good win.' But we're kind of like, 'Bro, don't do that right now.'"

Williams confirmed this: "There was definitely some etiquette that I did not follow, I would say."

Often described as a renaissance man, his diverse interests have been well chronicled, including on this website. Over time, however, he realized being on the court was different. "Sure, those other things were fun," Williams said, but he had found something he couldn't find anywhere else.

"Basketball was just something that allowed me to be myself," he said.

Williams preferred being in a group to playing individual sports. He could bring his personality to the gym, his "comedic energy that also was passionate and driven." He figured out that, on a team, he could lighten the mood and be the selfless person he wanted to be.

"That's something that I remember being super special," he said.

Celtics forward Grant Williams is far from a typical rookie. Michael Meredith (CBS Sports)

Williams was a favorite of NBA Draft experts because of his versatility, and he was a media darling because he was just as well-rounded as a person. As I watched video breakdowns and read up on him, I wanted to know if there was a connection, if he saw life and basketball the same way.

"Definitely," he said.

Being a nationally ranked chess player helped with his analytical thinking. The family motto is to stay seven steps ahead, and when Williams arrived in Knoxville, his mother had him write seven goals on a whiteboard. But it is not just that chess showed him the importance of knowing his opponent's strengths and weaknesses, or that doing karate as a kid helped him to be light on his feet, or that, through music and theater, he had experience being creative within a defined role. A walking advertisement for David Epstein's "Range," Williams brought a growth mindset to everything he did.

"The way I look at life is, if you learn off the court, you can learn on the court," Williams said. "So if you're able to learn a language, learning a play should be easy. If you're able to learn what to do and how to build something, you should be able to pass the ball in a certain way because your hands will be used to doing different things that other people can't. I've always said that, if you're expanding yourself off the court and do more things and create more habits, you'll be able to do more on the court."

Williams went further. Looking around the league, he noticed that specialists tend to, well, specialize.

"There might be a guy who's super driven in fashion and that's all he focuses on, all he cares about," Williams said. "And you see him on the court and you're like, 'Oh, well, all he cares about is defense, he doesn't care about scoring the basketball, he doesn't care about learning plays, he just worries about guarding his man.' Versus the guys who think about it like, 'Hey, I want to be able to go into fashion, I want to go into investing, I want to go into just honestly giving back to the community, I want to do all these things in my life,' and, next thing you know, they're the same type of player: In the game, they're like, 'Oh, I do love passing the ball, I do love scoring the ball, I do like playing defense and I could maybe eventually learn how to run plays and call plays myself.'"

There was a symbiotic relationship between the game and his other interests. Basketball reinforced lessons he'd learned outside of it and taught him "new things about myself," he said.

As is customary at Providence Day, Field asked upperclassmen on the basketball team to show Williams around when he arrived. "Grant was different from a lot of the freshman we met," Lucas Chamberlain, then a junior, said. Most were quiet and deferential. "And Grant never stops talking."

Williams immediately told Chamberlain that everyone calls him "The General."

"When he shows up and he talks as much as he does, a lot of the kids get annoyed by him," Chamberlain said. "I don't know, I never really got annoyed with him. I thought it was funny how much he talked, and I knew that he always meant well by everything he said."

Chamberlain said that Williams "was never Mr. Cool, but he wanted to be," at least in the beginning. But Wertz had recommended the private school because it was a place where "it was OK to be nerdy," he said. By the time he was singing and tap-dancing in the school play as a senior, he had long since ditched his aspirations of being Mr. Cool.

While Williams and Chamberlain became best friends almost immediately, there was an adjustment period before the rest of his teammates fully appreciated his brain and his talent. At that point, they didn't mind all the talking, nor that he instructed and corrected them at practice. This became a predictable pattern.

Minnesota Timberwolves wing Josh Okogie, an AAU teammate with Team CP3, said that "we tried to always get him to shut up," without much success.

"Grant talked about everything, anything," Okogie said. "He's a smart guy, so he would talk about science and why the Earth is shaped the way it is. Just some weird stuff. We're like, 'Oh, we really don't care.' But that's what makes Grant, Grant. That's what makes him special, man."

Waters, the Celtics rookie, said that the veterans' first reaction to Williams was oh my God, dude, shut up, "but then the more they got to know him, the more they understood who he was, they started to embrace him more."

"You just get used to me," Williams said. In time, teammates get to the point where, instead of making fun of him for "listening to Taylor Swift or something like that," their only reaction is oh yeah, that's Grant. Waters said no one can discourage him "because he's going to make a joke about it and just keep going."

"We just let Grant be Grant," Smart said.

Williams was not considered a top-150 player in his high school class. "We always thought Grant was going to be 7-foot tall," Wertz said, and skepticism spread when he stopped growing.

Instead of trying to transform into a wing, though, he relished matchups with highly touted big men Bam Adebayo and Harry Giles. He left MB1 for a smaller role with Team CP3 because he wanted to play against Giles in practice and test himself in the EYBL. Harvard, Yale and Princeton offered a security blanket, and Williams turned it down.

"All the coaches, my parents, even his mom wanted him to go to an Ivy League school," Chamberlain said. "His only [high-major] offer was Tennessee, and we were like, 'Dude, the odds of you making it to the NBA -- we love you, we think you can, but it's a miraculous thing if you can make it to the NBA.'"

His decision, Chamberlain said, makes sense when you see he is "the one making eight trades a week" in fantasy football and NBA 2K's franchise mode. Growing up, he and Gabon played physical one-on-one games in their grandfather's backyard, where the "court" was a driveway about 15 feet wide. As a high schooler, Williams visited Gabon at college and dunked on him in front of the entire team. He called it one of the greatest accomplishments of his career.

"He's going to tell you I did it once," Williams said. "I did it like four times."

Competitiveness alone, however, does not account for how he handled what the Volunteers call "fat camp," run by strength and conditioning coach Garrett Medenwald.

Knowing he'd agreed to send Medenwald a photo of everything he ate, Williams had to think twice about potential trips to Cook Out. When about 50 bags of extra buttery popcorn arrived at his dorm courtesy of his mother, Medenwald promptly confiscated the contraband. Williams watched from the treadmill as coach Rick Barnes ate a bag.

In between extra cardio sessions and exercises designed to develop elasticity, he and Medenwald discussed how variables from meal timing to sleep affected his performance.

"Before you know it, he's not wearing a shirt anywhere," Medenwald said.

Schofield, who went through fat camp with him, said that Williams "knows what he wants in life." A certain conviction is earned when you are at the top of your class, in the school play and convincing fellow basketball players to participate a regular game of Settlers of Catan.

"You kind of just have an idea of how you want to live your life," Williams said. "And who you want to be and also how you want to play."

Williams wanted to see how far staying true to himself would take him, basketball-wise and otherwise. In a green tracksuit at MSG, he said the only reason he was wearing "something like this" is that it is from his cousin's clothing line.

"Outside of that, I'm still wearing my Nike I-don't-even-know-what-these-are-called shoes. Running shoes," he said, pointing to his Air Zoom Pegasus 35s. "Swag-wise, I'm not the guy to look like. But I always just said be yourself and be comfortable with who you are."

That night, Williams was at his most animated during Tacko Fall's four-minute appearance, the 7-foot-5 center's first of the regular season. Fall's first basket, a dunk, brought Williams to his feet on the sideline, stomping on the court in celebration. A second inspired a flex and a cheek-to-cheek smile.

Fall said that Williams is "always bringing up the mood at the most unexpected moments." Waters said that he "brings a sense of unity" to the team, and that "you just kind of fall in love with Grant."

"Grant is just a happy guy, a happy spirit, you know?" Smart said. "When you got a guy that's just happy and smiling, it's hard for you to be down."

Perhaps it is understandable that NBA executives wanted to see for themselves if Williams was for real: He seems to be an endless fount of positivity, which, in addition to being a 20-year-old professional athlete who graduated college in three years and avoids boredom by learning new languages and instruments, is so undeniably admirable as to be suspicious.

Williams is flattered by friendly quotes and is proud of his education, but he wanted to make it clear that he is a product of those who influenced him and there are "way more intelligent people than me." Mature as he may be, no one his age is devoid of bad habits.

"Honestly, if we're keeping it real right now, that man has no bad habits," Gabon countered. "And it's ridiculous. The only bad habit he has is being too playful at times. But I think he even corrected that. He knows when to be serious now and he knows when to play. I've known this man since he's been on this earth, OK. The man doesn't smoke, the man doesn't drink, the man doesn't do anything. The man stays out of the way."

Proud as can be, Gabon still doesn't understand how his little brother has done it. At Williams' preseason debut, conveniently scheduled in Charlotte, Gabon's heart raced as he remembered his little brother's first awkward forays into basketball, late nights in the gym and "a lot of sad moments that got us here."

Williams' classmates at Providence Day might not have been able to tell, but "we had ketchup sandwiches when we were growing up," Gabon said. They moved from Houston as kids, and, while he didn't have the same high school experience his older brothers did, Gabon said he "embraced all of the struggle, 'cause we come out of the most struggling community in Charlotte," and "took it with him."

As hard as it is to imagine, Gilbert said there was a time, before he got into basketball, that he was "the quiet one." Williams needed to develop his positivity and his personality, and he discovered that focusing his energy outside of himself gave him more of it.

"You know where you come from," Williams said. "And I was in a neighborhood where it was kind of like a mix. I would be going back to West Charlotte, like Beatties Ford Road, when everybody was like, 'That's Beatties Ford Road,' but no one would really know that. They'd just imagine I'm that goofy character that's smiling and around. My parents were divorced and I was like, 'Yeah, they've been having this divorce for 14, 15 years. It's one of the worst divorce cases in history.'

"You never know what's going on in someone's world. But for me, that's how I kind of approach every day. You never know what's happening, and you just go on with a smile and you might be able to pick somebody's day up."

The only thing misleading about Williams is that he gives off the impression that it's all effortless. In a summer spent mostly in Boston, he took a duck boat tour, threw out the first pitch at a Red Sox game and appeared at as many community events as he could. He said he was thankful for fans making him feel welcome. He didn't know anyone there outside of his fellow rookies, though, and Chamberlain said that he called a lot at first, a bit bored, wanting friends and family to visit.

Two months into his professional career, Williams is contributing for a 12-4 Celtics team that is exceeding expectations with dramatically improved chemistry and elite defense. He has yet to hit a 3-pointer and has not been much of a scoring threat, but has been as solid as advertised as a defender and is beloved in the locker room.

His track record suggests he will do the little things with a smile on his face and gradually expand his game. Gabon isn't arguing anymore.