BOSTON – One person’s smile can light up an entire room.

Or, in Kemba Walker’s case, it can light up an entire arena.

The nine-year NBA veteran has an incomparable glow that radiates from the hardwood all the way up to the rafters of any basketball venue inside of which he steps. What’s unique about his gentle, gracious and genuine grin is the constancy of it; whether the 29-year-old point guard is winning or losing, whether his shot is falling or clanking off the rim, that smile never leaves his face.

Such an aura is unusual to come by in the modern-day NBA, especially in a star player. There’s so much pressure that comes with the job, so many outside expectations, and so many ups and downs that take form over the course of a grinding basketball season. It’s a roller-coaster ride that can cause one’s emotions to derail, but the Boston Celtics’ floor general enjoys every dip, loop and turn of the ride.

“It’s because I’m playing a game that I love,” Walker tells Celtics.com. “A game I’ve been playing for a long time. So, I just try to enjoy it. I just try to make it fun for my teammates, I try to not have bad body language, and I try not to be down. That’s just who I am. That’s just who I’ve been for a very long time.”

Walker developed his unwavering love for the game while growing up in the Bronx, New York. He was a small guard, standing just 6-foot and weighing only 170 pounds during his high school upperclassman years. But his desire to compete allowed him to stand tall among his peers.

One of those peers in Walker’s youth basketball network was fellow Celtics guard Brad Wanamaker, who grew up in nearby Philadelphia. The pair faced off several times during their high school days, and Wanamaker was always impressed by the way Walker carried himself on the court.

“He always had this grit to him,” Wanamaker recalls. “New York guards and Philly guards, growing up we always battle, show who the best guards are coming up. And every time I saw him on the circuit somewhere, whether it was AAU or in a high school tournament, just seeing his willingness to go out there and work. You always saw the toughness in him. Then the talent came and there was just no stopping the guy.”

During the college recruiting process, coaches looked past Walker’s small frame and instead focused on his competitive edge. As such, he wound up being one of the top recruits of the 2008 high school class. ESPN ranked him as the No. 2 point guard and No. 14 overall player in the nation, and top collegiate programs from all over the country sought his commitment.

Walker wound up choosing the University of Connecticut – a close-to-home option with an illustrious basketball history and the opportunity to be coached by one of the greatest legends in the history of the game, Jim Calhoun. Though, by the end of his three-year tenure in Storrs, Connecticut, which was capped off with a national title, it was Walker who had established legendary status in Calhoun’s mind.

“I coached 50 years and had 30 NBA players who played at least four years,” Calhoun said while visiting Walker at a Celtics training camp practice this fall. “He’s as special as anybody I’ve ever had in terms of leadership, caring, and just an incredible confidence with humility, which is a hard thing to have.”

Walker’s leadership and humility would be tested right off the bat upon entering the NBA. During his rookie season, his Bobcats won just seven out of 66 games during the lockout-shortened 2011-12 campaign. Though, not even experiencing the lowest single-season winning percentage in NBA history could alter Walker’s love for the game. If anything, that challenging campaign only strengthened his desire to win.

“Those kinds of situations, they humble you,” Walker says looking back. “For me personally, it definitely humbled me, and it just made me work extremely hard to try and become the best player I could be.”

Walker grew immensely during his sophomore season, and Charlotte grew with him, tripling its win total from the previous season to 21 victories. The Hornets then more than doubled-up on their success the following season, as they secured 43 wins and a playoff berth.

Charlotte’s success, however, would max out right around that level of victories. It never finished more than seven games above .500 and never broke out of the first round of the postseason. Yet, the three-time All-Star stuck with that team for eight years, and not once did that smile leave his face.

With that being said, Walker felt like something was missing. When he reached the final year of his second contract with the Hornets, he realized that it may be in his best interest to explore his options and possibly look into beginning a new chapter.

“We’d talk a lot,” Calhoun recalled of Walker’s 2018-19 contract season. “(I’d ask), ‘What’s going to make your mind up? Because it’s your decision.' And he’d always say, ‘Winning. I want to win. I’m at that point in my career. God’s been good and I’ve made a lot of money, but I want to win.’”

Walker wanted to experience success just like he had in Storrs, where he and Calhoun had won a championship. As he narrowed down his options, Walker discovered that the perfect situation happened to be less than 100 miles northeast of where his former glory had been achieved.

Boston had everything that Walker wanted: a winning tradition, strong basketball culture, a promising future, and more.

“He knew what the Celtics represented,” said Calhoun, who recently came out of retirement to become the first head coach of the University of Saint Joseph (Connecticut) men’s basketball team.

They represented pride, tradition and success in the form of 17 championship banners. In signing with the C’s, it became Walker’s mission to experience that pride, to carry on that tradition and to build upon that success by bringing Banner 18 to Boston.

“For me, it’s the competitiveness of this organization,” Walker said shortly after signing with the Celtics in July of what drew him to the team. “They’ve been winning for years; you see all the banners. It’s a winning organization and I want to win. That's what I’m about. Throughout my basketball career, as a pro, I haven’t won consistently. I just want to get a taste of that, and I thought this would be the best place for me to do that.”

Walker had also never been surrounded by such a strong supporting cast of players before. He was joining a core that included the likes of a former All-Star in Gordon Hayward, a pair of young, rising studs in Jaylen Brown and Jayson Tatum, and an All-Defensive backcourt mate in Marcus Smart.

Being the new guy in a group like that would have been daunting for some players, but Walker made it a point to start building strong relationships with them all from the get-go.

“I’m all about the camaraderie, I’m all about the togetherness,” Walker said in mid-August. “I’ve always felt that your off-the-court relationships translate on the court.”

He and Hayward had already established an off-court relationship, as they had crossed paths many times over the course of their careers and even almost became teammates in Charlotte a few years back.

Meanwhile, the other three core players would get to know Walker very well over the summer, as they all joined forces to represent one-third of the United States Men’s Basketball team at the FIBA World Cup in China.

From early-August to mid-September, the three-leaf shamrock of Brown, Smart and Tatum formed into a four-leaf clover, as Walker seamlessly integrated himself into the group.

“I had no doubt while I was coaching him this summer that he’d be great for the Celtics, given not only his ability on the court but the chemistry he generates with a group,” said Golden State Warriors head coach Steve Kerr, who served as a US Men’s National Team assistant. “Everybody loves playing with him. He moves the ball, he plays hard, he’s just fun to be around.”

The rest of the Celtics team got in on that fun as soon as training camp began in early October. Walker quickly gained everyone’s respect through his hardworking and humble approach, and he was immediately regarded as one of the leaders of the team.

“I think he’s one of the best leaders I’ve been around,” says Celtics head coach Brad Stevens. “It has been pretty well documented in his demeanor and his way that he goes about every day, his work. He’s a real positive guy. He cares about the team. He does a lot for the team. He goes out of his way for people. He brings the most out of the guys that he’s playing with.”

That doesn’t just go for his fellow core players. Walker tries to bring out the best in every member of the team from the top of the rotation all the way down to the last guy on the bench.

Having such a supportive leader is especially important for a Celtics squad that has six rookies on its roster. Through his patient mentorship, Walker has assisted in helping many of those first-year players make a comfortable transition from the college game into the NBA.

“He’s a guy that picks you up,” says rookie forward Grant Williams. “He’s not a leader to bash you and tell you what you’re doing wrong. He’s more of a motivational leader in terms of understanding that you’re talented and understanding that you’re here for a reason, and he’s going to tell you that, specifically, even if you mess up and do something wrong.”

For example, there was one particularly frustrating play for Williams during a Dec. 11 matchup in Indiana that called for a brief Walker intervention. In this instance, Williams was defending Pacers big man Domantas Sabonis mid-way through the second quarter, and he was doing a good job of it on this particular possession. However, he bit on a pump-fake with 0.3 seconds left on the shot clock and allowed Sabonis to convert an and-one bucket.

Williams was livid with himself for the miscue, so Walker strolled over and gave the rookie a brief pep-talk.

“He just came over and said, ‘You played great defense the whole possession, and you know that. So just stay down and you’re good. You’re good. Don’t worry about it,’” Williams describes. “And I’m just like, ‘Yeah, yeah. That’s true.’ So, he has great leadership qualities in that aspect.”

Such positive energy is contagious and particularly important to give off around role players who often feel pressured to perform during short stints off the bench.

“It rubs off a lot,” Wanamaker, the Celtics’ backup point guard, says of Walker’s energy. “It makes you enjoy the game more because sometimes you get caught up where you take the game too seriously or you put too much pressure on yourself. Us guys behind him, when we go out there we’re always thinking, ‘perfection, perfection, perfection.’ But to see him out there relaxing at times and just enjoying the game. At times when he’s missing his shot or he’s turning the ball over, he’s still smiling. And that helps a lot – more than he knows – just that it’s OK to relax, smile, and move on to the next play.”

Though he may seem relaxed most of the time, Walker is always locked in. No matter what the situation is, he’s consistently ready to contribute and to help deliver a win.

A great example of his locked-in nature took place Dec. 9 during a home matchup against the Cleveland Cavaliers. With a couple of minutes left in the third quarter, Walker was pulled from the game for what appeared to be the last time after he had helped to build up a commanding 28-point lead. However, Cleveland was able to chisel its deficit down to 13 over the ensuing eight minutes, causing Stevens to call upon Walker’s services once more.

Many players in Walker’s situation would have mentally checked out by that point, but he was ready to close out the game. And boy did he, as he checked in and quickly knocked down three 3-pointers over an 82-second span to help the C’s gain back total control before cruising to a win.

“At the end of the day, you have to stay engaged throughout the whole game,” Walker said after that win. “You just never know. In this league, 20-point leads go so fast and teams can score in bunches really fast, regardless of the score. So, you just have to stay engaged.”

Stevens was so impressed by Walker’s preparation in that moment that he used it as a major talking point of his post-game discussion in the C's locker room.

“I just told the team afterward, if you want to be special, then model after Kemba,” the coach recounted. “Because Kemba sits over there, thinks his night is done, gets put back in the game, drills three 3s and ends it.

“I mean, special is not for everybody, but that's just different,” he added. “That's just always ready, always wanting to be called upon, always loving to play. He's not untying his shoes; he's staying ready because he knows this game can change in a heartbeat.”

A heartbeat is exactly what Walker is becoming for this Celtics team. Every day he shows up to the gym, he has that trademark smile on his face, ready to work and ready to bring out the best in everyone around him.

“That’s tough to do every day,” says third-year wing Semi Ojeleye, “because you’ve got your own life going on, everybody’s got their own stuff going on. But he does his best to always be talking, always trying to lift everybody up no matter what he’s got going on.”

As a coach, Stevens greatly appreciates that quality in Walker, as it helps to make his job a whole lot easier.

“Most coaches and players get caught up in the emotions of the season,” Stevens says. “And the down days, for a lot of us, you can probably sense them. Whereas there are some guys that just always seem to have an uplifting spirit, and he’s one of them. I had a few of those guys at Butler. I’ve had a few of those guys here. But Kemba is definitely one.”

Winning also helps to maintain an uplifted spirit. Walker and the Celtics have been doing plenty of that so far. As of Jan. 12, the team was off to a 26-11 start, good enough for third place in the Eastern Conference, with Walker averaging team-highs of 21.9 points and 5.2 assists per game.

Near the beginning of the season, the C’s won 10 games in a row, which was by far the most consecutive victories that Walker had ever achieved at the NBA level.

“I’m just liking the way I’m feeling after the games,” he said after securing the 10th victory of that stretch. “Like, I just feel good. That’s all I’m thinking about. I [couldn’t] care less about the streak. Just the feeling of winning, it feels good.”

Walker doesn’t just feel that way inside. He expresses it with his emotions and with his actions.

“When we win games, Kemba is one of the happiest guys in the locker room every time,” says third-year big man Daniel Theis. “He’s just screaming. He loves winning … And when he’s happy so much after winning games, everybody is happy.”

Adds Stevens, “He loves the game and he loves being around his teammates, and you can feel that when he’s around.”

You can feel it when he’s winning. You can feel it when he’s losing. You can feel it when his shot is falling, and even when it’s clanking off the rim. Walker’s positive attitude never falters, and that radiant smile he wears, powerful enough to light up an entire arena, never leaves his face.

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