Why did the Celtics swap Kemba for Horford?

Rumors of a potential Kemba Walker trade didn’t take long to materialize. The four-time All-Star is headed to Oklahoma City with the 16th pick in the 2021 Draft and a 2025 second-rounder. In return, Boston welcomes back Al Horford along with Moses Brown and a 2023 second-round pick, according to ESPN’s Adrian Wojnarowski.

Nobody has anything negative to say about Walker, the person. But his performance on the basketball court forced Boston’s hand on multiple levels.

Kemba spent this entire past season in and out of the lineup trying to ensure optimal health come playoff time. A lack of reliability from your third-best player is a lot to ask of any team, but the Celtics would’ve happily stomached it if it wound up paying dividends in the postseason.

Instead, Walker appeared in only three of Boston’s five first-round games against the Nets, never scoring more than 17.

At 31 years of age, it’s hard to imagine Walker’s health heading in the right direction, at least not in the ways a Celtics team hoping to go on an extended playoff run would need. And with the emergence of Payton Pritchard in a standout rookie season, Boston didn’t feel the need to bank on Kemba’s knee any longer.

But while health may have been the driving force behind trading Walker, basketball reasons exist as well.

As talented as they are, Jayson Tatum and Jaylen Brown are scorers and haven’t maximized their potential as playmakers yet. They can get shots for themselves but haven’t implemented the ability to do so for others.

Walker is cut from a similar cloth. Though not a selfish player, he has a scorer’s mentality. He tried to focus more on playmaking during the final weeks of the regular season, averaging 7.0 assists per game over a seven-game stretch. But his rise to stardom came thanks to his ability to put the ball in the basket.

It’s who he is as a player. Nothing can change that, nor should it. But it’s problematic for a team that already has two such players leading the way.

In Horford, the Celtics have attempted to fix that problem by acquiring some much-needed balance at the offensive end. Celtics fans are well versed in what he brings to the table. Not a primary scorer, Horford’s best offensive trait is his ability to connect the other four players he’s sharing the court with at any given moment.

“Al played a critical role both on and off the court during his time in Boston, and we’re excited to welcome he and his family back to the Celtics,” said Stevens. “His ability to elevate teammates with his experience and leadership make for a great addition.”

Whether it’s moving the ball from one side of the court to the other or finding teammates from the high post, Horford has established himself as a playmaking hub from the center position. He averaged at least 4.0 assists in the four seasons before the 2020-21 campaign, where he averaged 3.4 in under 28 minutes a night.

The Celtic ranked top-10 in isolation frequency in each of the last two seasons, which checks out given the personnel of Tatum, Brown, and Walker. But hero ball has its limitations, specifically in crunch time, where the Celtics ranked 26th in offensive efficiency this past season.

When your offense is boiled down to a 1-on-1 affair, it’s easier for defenses to offer more resistance. With Horford’s passing ability back in town, the Celtics can implement more nuanced sets and have Tatum and Brown exert less energy to get up a decent shot.

The perception of what Horford can still bring may have taken a dip after a tumultuous stop in Philly and a one-year exodus in OKC, where he appeared in just 28 games with the Thunder in rebuild mode. But he looked rejuvenated in that limited time, complementing his aforementioned assist numbers with 14.2 points and 6.7 rebounds a night.

He also shot 36.8 percent on a career-high 5.4 3-point attempts per game, returning a wrinkle none of the current Celtics big men can provide.

We won’t know if this blockbuster trade improves Boston’s title chances for a while in part because concerns need to be addressed elsewhere. The roster is now comprised of four centers with Horford and Brown joining Robert Williams and Tristan Thompson on the depth chart for now. Without Kemba, are the Celtics confident letting Marcus Smart run point or handing the keys to Pritchard in his second season? Will there be an answer in free agency or with another trade?

But after last season’s disappointing finish, it was clear that the Celtics couldn’t just run it back. A change was needed. In his first big move since taking over the front office, Brad Stevens made sure one would be made.