Eighteen shamrocks.
That’s how we’ll always remember Al Horford’s time in Boston. Nine years ago, that was how he declared his intention to join the Celtics on social media. It was both a celebration and a promise. For the first real time in team history, a big-time free agent was choosing to come to Boston and, with him came true hope of raising the franchise’s next banner.
It took almost another decade — and two different stints in green — but Horford delivered on that promise. He nurtured a young team, twice delivered them to the championship stage, and finally secured that elusive Banner 18 in 2024. He helped restored Celtics Pride while ensuring the team was a title threat in nearly every season he wore green.
On Sunday, after months of speculation that Horford would eventually land in Golden State, Horford reportedly agreed to a multi-year deal with the Warriors.
It’s fair to wonder if Boston’s superstar tandem of Jayson Tatum and Jaylen Brown would have had the early success they enjoyed without Horford in Boston, or whether they would have gotten over the final hump without his return. Horford’s stat lines have never jumped off the page, but he was a rock-steady presence whose thirst for a title inspired everyone around him to give everything they had on the court.
Players routinely named Horford their favorite teammate. In the aftermath of falling short in title quests before 2024, coach Joe Mazzulla often noted that his biggest regret was not being able to help Horford complete his own elusive title goal.
But they got there, eventually. There’s a series of photos that show Tatum’s hands wrapped around Horford’s shoulders as he exults on the podium while the Celtics are being presented with the Larry O’Brien trophy. Brown is smiling widely next to them. Boston had accomplished its elusive goal.
Peter Casey-USA TODAY Sports
Peter Casey-USA TODAY Sports Jayson Tatum often has called Al Horford the best teammate he’s ever had.
When Horford first arrived in Boston, there was a different core he expected to guide forward. It was Jae Crowder, Isaiah Thomas, and Kelly Olynyk who had steered Boston back on track to being a contender. Horford marveled at the energy inside TD Garden as Boston took two games off his Hawks in Round 1 of the 2016 playoffs.
Less than three months later, he agreed to come to Boston. Celtics brass were boarding a private plane on the tarmac in the Hamptons, having just pitched Kevin Durant on the possibility of also being in Boston too, when word arrived that Horford was joining the Celtics.
A celebration erupted. The Celtics’ title hopes had been given a major jolt with Horford’s arrival. Six trips to the conference finals followed over the next eight seasons. There were heartbreak and frustration along the way, enough that Horford departed for the rival Sixers after a maddening 2018-19 season. But his return for the 2021-22 season reignited Boston’s title hunt.
Even at his advanced NBA age, the Celtics worked diligently to keep Horford healthy, knowing how vital he was to their title hopes. They sat him on the second night of back-to-backs and limited his overall wear and tear. They were rewarded as he routinely thrived on the biggest stages.
The image of Horford flexing after steamrolling Giannis Antetokounmpo on the way to the basket during the 2022 run was a signature moment in Boston’s march to the Finals that year.
Invariably, because this is Boston, where an astounding number of jersey numbers mingle amidst the 18 title banners, the question will be asked whether Horford’s No. 42 deserves to hang among the Celtics’ other legends.
Getting up there with only one title is a tough chore, but not impossible. Horford didn’t change the culture the way Kevin Garnett did in joining a team that had been tanking hard a year before. Horford also didn’t have the longevity of a player like Paul Pierce.
But the Celtics did a whole bunch of winning with Horford, who sits 10th all time with 72 playoff wins in a Boston uniform. The only players ahead of him: John Havlicek (108), Bill Russell (107), Robert Parish (100), Sam Jones (100), Larry Bird (99), Kevin McHale (98), Don Nelson (81), Satch Sanders (81), and Brown (80). Horford is tied with both Jayson Tatum (at least for now) and Pierce in playoff victories.
Horford’s career averages in Boston don’t leap off the page: 11.2 points and 6.8 rebounds per game over 465 career games in seven seasons with the Celtics. Those numbers perked up a bit (11.5 points and 7.7 rebounds per game) over 119 playoff games, including 113 playoff starts.
But Horford taught the Jays how to be professionals, and instilled in them that winning is all that matters. He accepted any role the team desired, including shuffling to a reserve role after the team acquired Kristaps Porzingis and Jrue Holiday during the summer of 2023. That selflessness was a huge part of Boston’s march to Banner 18.
Maybe that’s not enough to get No. 42 to the rafters. But the people who were here during Horford’s tenure know how vital he was, and there will be supporters to get 42 up there.
Even in the immediate aftermath of his departure in 2019, the long-term outlook was bleak. Kemba Walker brought a bunch of joy, but his knee betrayed him. Brad Stevens’ very first deal as president of basketball operations was to bring back Horford and get off Walker’s remaining money, and it fueled the team’s return to title contention.
It’s hard not to wonder if Horford’s time here might have extended another season (or two) if Tatum never tore his Achilles in the 2025 playoffs. The Celtics couldn’t quite commit to the money necessary to keep Horford around without being a surefire contender while Tatum rehabbed.
It won’t be the same not having the Horfords at TD Garden. Over the last two seasons, Horford’s young son, Ean, was a staple near the Boston bench. Horford’s wife, Amelia, and other children were routinely courtside.
The Celtics can’t possibly replace the intangibles that Horford brought. It places even more responsibility on Brown and Tatum to be the leaders of this team.
But Horford’s mark will sit above TD Garden in perpetuity: the team’s 18th banner delivered in the aftermath of Horford’s 18 shamrocks.
