What did we learn from Al Horford’s first game back?

For the first time since Game 5 of the NBA Finals, we witnessed Al Horford’s greatness on the court. Horford was the load-bearing wall that held everything together during the last playoffs. While Kristaps Porziņģis was out, Horford ensured that the elite defense held firm and the spacing remained intact. Without Horford, the Celtics might still be tied with the Los Angeles Lakers at 17 NBA titles. How sad is that?

Nonetheless, the past is the past, and a new season is about to begin. Last night marked Horford’s first preseason game, and we already have some insights into how Joe Mazzulla and his coaching staff may plan to use him this season.

Doubts about the double-big lineups.

Last season, Horford’s primary role was to back up Porziņģis, with Luke Kornet serving as the third option in this two-man rotation. During the 2024 regular season, Horford played 908 minutes as the lone big, 587 minutes alongside Porziņģis, and 245 minutes with Kornet. That’s one of the reason Horford is unique, his ability to play and perform alongside another big when needed.

Before the game, Horford had nothing but great things to say about Celtics’ other big men:

Last season, the Horford-Porziņģis combination showed strong defensive synergy, their presence together brought the Celtics’ defensive rating down to 110.13—compared to 113.59 with only Porziņģis on the floor. However, while the defensive impact was clear, the offensive rating remained stable, and the spacing wasn’t as elite as with the starting five.

Throughout his career, Horford has developed into a reliable three-point shooter, but he doesn’t offer the same spacing value as an elite shooter like Porziņģis. Horford also can’t consistently shoot from two steps behind the arc, which the Latvian big man does with ease. This creates potential spacing issues when Horford shares the floor with another non-shooting big.

A play from last night illustrates this issue perfectly: Xavier Tillman set a pin-down screen for Jordan Walsh while Jakob Poeltl stayed low, blocking the driving lane. On the opposite side, Horford was just one pass away, but Chris Boucher chose to stay in the paint, focusing on taking away Derrick White’s drive rather than guarding Horford closely.

It’s hard to say how often we’ll continue to see these double-big lineups, but they don’t seem to fit seamlessly with the principles of Mazzulla Ball. For the Celtics to excel, they need the space to attack seals effectively.

Al Horford is still a killer whale…

Although the offense becomes more challenging with another big on the floor, Horford can still attack mismatches. To get him involved, the Celtics ran a few empty-side pick-and-rolls for him, which generated good opportunities for the veteran.

…But he can be hunted, too!

As a Celtics fan, I’ve been concerned about Horford’s drop coverage for a couple of seasons now. While his ability to switch remains elite, his drop coverage shows some limitations, and opponents are starting to exploit it.

I first noticed this during the 2023 playoffs, when the Atlanta Hawks extended the series to six games by targeting Horford’s drop defense with Trae Young. Of course, there’s no shame in that—Young is an elite offensive talent.

However, last night, we saw less talented players going at Horford, which raises some concerns. Why do the Celtics continue to rely on drop coverage with Horford when we know how effective he is in switch-all schemes?

The drop coverage might be more effective with Kornet on the floor, but that brings us back to the double-big lineup dilemma. Maybe the defensive boost from the double-big look outweighs the spacing challenges. Perhaps that’s what Joe Mazzulla had in mind when he mentioned Horford’s ability to keep reinventing his game.

Horford mentioned after the game that Joe Mazzulla “keeps challenging them not only defensively, but also offensively, to think the game, to play a certain way.” Maybe the double-big approach is part of that new challenge.

After spending many seasons as the lone big, Horford has shown that he can also play alongside another center. In fact, he did it so well during his NCAA days that the Florida Gators won back-to-back titles with him. Let’s hope the Celtics can achieve the same destiny this season.

Photo by Streeter Lecka/Getty Images