Lucky 18: Celtics Claim NBA-Record Title After Dominating Postseason Run and Past Heartbreak

The 78-year history of the Boston Celtics is so extensive even the CliffsNotes version takes up a handful of pages. Seventeen championships entering this season, 23 NBA Finals appearances, nearly as many division titles (34) as the Minnesota Timberwolves have played seasons (35). So many retired numbers are stitched to the banners hanging from TD Garden that one name—“Loscy,” for Jim Loscutoff, a defensive stalwart of seven championship teams, who requested that his number be kept in circulation so others could wear it—hangs with them. For a franchise this steeped in success, it’s difficult to stand out. The 2023–24 Celtics, NBA champs for the 18th time after dispatching the Dallas Mavericks in five games, found a way to do just that.

By the numbers, it was brilliant: a 64-win regular season and a 16–3 run through the playoffs, including an 8–1 stretch in the final two rounds. The 80–21 combined record generated the second-highest winning percentage in team history and the best postseason mark of any Celtics title team. Boston didn’t just beat teams this season—it bludgeoned them, with the fourth-highest point differential in NBA history. 

“You can’t have a philosophy or a way of playing if you don’t have a group of guys that are willing to buy into it and be disciplined,” Celtics coach Joe Mazzulla said. “Quite honestly, this group of guys has been through so much in the league, they know what it takes.”

Indeed, while all championships are equal, how they are earned can vary. Some are bought, which in some ways can be said for Boston’s last, in 2007–08. That banner was raised months after the Celtics acquired Kevin Garnett and Ray Allen, teaming them with an in-his-prime Paul Pierce. This title was grinded out, achieved after a bruising seven-year odyssey filled with highs (five trips to the conference finals) and lows (a loss in the ’22 Finals) with all the scars to prove it. “We did it,” was all Jayson Tatum could muster, as the green-and-white confetti rained down around him, wearing the same incredulous look shared by teammates packed around him. “We’ve had a lot of hardships the last few years,” Al Horford said. “But this team has been resilient. And we’ve continued to work.”

In the closing minutes of Game 5, as Mazzulla pulled his starters, Tatum and Jaylen Brown met at the end of the Celtics’ bench, exchanging a handshake, a hug and a long sigh of relief. Few teammates have achieved the success of Brown, who was a rookie for that first conference finals trip in 2017, and Tatum, who joined a year later. Fewer have faced the same level of scrutiny. As recently as May, after the Celtics swept their way to the Finals, pundits questioned the health of the Tatum-Brown relationship, using footage of Tatum applauding Brown’s conference finals MVP as Zapruder-like evidence. It was, as always, goofy. When Brown collected the Finals MVP, a reward for timely offense and dogged defense against Luka Doncic, he turned to Tatum and said, “We share this s— together.”

“We’ve been through a lot,” Brown said. “The losses, the expectations. The media have said all different types of things. We can’t play together, we are never going to win. We heard it all. But we just blocked it out, and we just kept going. I trusted him. He trusted me. And we did it together.”

Failure has fueled Boston’s stars. For Tatum, it was the 2022 Finals. A poor series against the Golden State Warriors—coupled with the sounds and images of the Warriors celebrating on Boston’s home floor that remain seared into Tatum’s memory—drove him to improve. His body, his passing, his post play. “Coming up short and having failures makes this moment that much better,” Tatum said. “Because you know what it feels like to lose.”

A championship is a validation of sorts for Tatum, who has the credentials of one of the NBA’s best players but is often spoken of like a player a cut below them. Tatum struggled with his shot in the Finals, connecting on 38.8% of his shots and 26.3% of his threes. But he found ways to impact winning. He collected 11 rebounds in Game 1. He handed out 12 assists in Game 2. In Game 5, Tatum finished two rebounds shy of a triple double. Only six champions have led their teams in scoring, rebounding and assists in the postseason. Tatum is one of them.

“To elevate yourself in a space that all your favorite players are in,” Tatum said. “Everybody that they consider greats or legends have won a championship. And all of the guys I looked up to won a championship, multiple championships. So now I can walk into those rooms and be a part of that. It’s a hell of a feeling. This is more [than] I dreamed about what it would be like. This is 10 times better.”

For Brown, the pain was more recent. Last spring, after the Celtics clawed their way back from a 3–0 deficit to even the conference finals, Tatum went down with an injury early in Game 7. Brown sensed opportunity. His relationship with Boston has been complicated. In 2016, Brown’s selection was booed on draft night—a trade for Jimmy Butler or the drafting of a more well-known playmaker in Kris Dunn was preferred—and over the years, his name has been digitally stuffed into the trade machine more than All-Star ballots.

Given a chance to shine, Brown wilted, shooting 8 for 23 from the field and 1 for 9 from three-point range in a lopsided loss. “I felt like the team was relying on me,” Brown said. “I dropped the ball. To me, it was embarrassing. It drove me all summer, drove me crazy.” In the Finals, Brown’s sturdy defense on Doncic helped Boston limit Dallas to under 100 points in each of its four losses. “The story and the journey,” Brown said, “is awesome.”

Everyone played a part. In 2016, when Horford met with Boston in free agency, Danny Ainge’s pitch was simple. “He said, ‘You can win championships in many places, but there’s nothing like winning in Boston,’ ” Horford recalled. “Nothing like winning as a Celtic.” Horford spent three years in Boston before bouncing between the Philadelphia 76ers and Oklahoma City Thunder, only to have the Celtics trade for him in ’21. He responded with three straight 60-plus-game seasons. In the Finals, in his 17th season and days removed from his 38th birthday, Horford shot 47.1% from three. “It’s been a lot of years,” Horford said. “I’m so grateful.”

On the parquet floor, Brad Stevens, hat turned backward, still resembling the baby-faced Butler boss more than the reigning Executive of the Year, celebrated with him. A career coach, Stevens was a curious choice to replace Ainge in 2021. Yet, as a coach, he had a feel for the roster. As an exec, he immediately showed the fearlessness to shake it up. He flipped Kemba Walker for Horford, moved draft capital for Derrick White, swapped Marcus Smart for Kristaps Porzingis and outbid several contenders for Jrue Holiday. Crashing a Stevens interview, a goggled Holiday draped an arm around Stevens’s shoulder and thanked him for bringing him there.

“I hope that when people watch us play, they see the joy that we play with,” Holiday said. “That we love playing together, and we got it done together.”

Stevens also hired Mazzulla, the boldest move of all. Two years ago, Mazzulla, just 33, was thrown into the deep end of the basketball pool, a back-of-the-bench assistant handed a title contender just days before training camp. The things he did well that season (57 wins, a trip to the conference finals) were overshadowed by the stuff he didn’t. The shaky rotations, the inconsistent timeouts, the combative public persona. Everything suggested that, perhaps, Mazzulla wasn’t ready for the moment.

Except he was. He fine-tuned the defense and built an offense around the philosophy that there is no such thing as too many three-point shots. He integrated Porzingis and Holiday, managed Horford and developed Sam Hauser into a valuable rotation player.

His personality? That’s just Mazzulla. He’s stoic, quirky, awkward even, a Salinger character brought to life. He shows UFC fights in film sessions and once attempted to block an opposing player from getting a free shot going into a timeout. In April, after Mazzulla was named the NBA’s Coach of the Month, White congratulated him. “He just looked at me and said, ‘Nobody cares,’ ” White recalled. During the Finals, Mazzulla was asked about the significance of the series featuring two Black coaches. Mazzulla wondered how many coaches had been Christian. On the eve of Game 5, Mazzulla, responding to a question about joining Red Auerbach in the ranks of Celtics championship coaches, said, “that will never happen if you don’t run back on defense, rebound, execute and get to your spacing.”

“He’s crazy,” Holiday said. “Anybody who knows Joe knows he’s crazy, and that’s pretty much it. But I think it’s maybe controlled madness. It’s definitely his way of preparing us and I feel like preparing himself.”

But it worked. It all worked. And it may again. The NBA has collectively bargained dynasties out in recent years, with Boston the sixth different team to win a title in as many seasons. But these Celtics have staying power. The entire rotation is under contract next season with Tatum, Brown and Porzingis under 30 years old. Stevens has a full cache of draft picks to work with. When the celebration is over, after the duck boat–led parade has finished, the expectations will return. 

“It’s Boston,” Mazzulla said. “Like, we wouldn’t want it any other way.”