Last season, the Celtics acquired Jrue Holiday and Kristaps Porzingis to create the ultimate spacing. As the season progressed, the Celtics ensured they always had players who could shoot the three and space the floor to open driving lanes. Thanks to that approach, the Celtics excelled at finishing at the rim.
Boston Celtics: 404 error, spacing not found
Indeed, they were one of the best teams—if not the best—at rim efficiency and driving efficiency last season. Thanks to their elite spacing, the Celtics stretched defenses so much that they made life impossible for their opponents. Opposing teams were too scared to leave any player open and therefore, couldn’t help at the rim.
Jaylen Brown noted that they used this spacing to hunt mismatches, find weaker defenders, and attack one-on-one in the best spacing possible. Teams were reluctant to help because they knew the Celtics wouldn’t hesitate to shoot from three.
Lately however, the spacing seems broken. Although the Celtics still drive as much as they used to, their efficiency has plummeted. Over the last 10 games, their field goal percentage after a drive is just above 45%, far from last season’s 53% efficiency. Worse, over the last 5 games, the average has dropped to 43%—ranking 26th out of 30 teams in that span.
What changed?
Teams aren’t scared anymore
Lately, Boston’s opponents seem fine leaving a shooter open from three and instead prioritize clogging the paint. Opposing teams are essentially giving the Celtics the same defensive treatment that Boston uses against them. They identify the weakest shooter on the Celtics and leave them open—or keep the weakside corner defender near the rim to rotate defensively, as the Lakers did below:
Opponents have done the math and realized it’s not worth following Celtics shooters beyond the arc, opting instead to protect the rim. For instance, if the Celtics shoot 70% at the rim but only 40% from wide-open threes, it’s more efficient to give up the triples. Shooting 40% from three is worth 120 points per 100 possessions, while 70% at the rim is worth 140 points per 100 possessions. On top of that, rim attempts generate free throws and can put opponents into foul trouble. Given this, teams now focus on defending the rim and leaving the perimeter open.
Beyond the drives
The drop in efficiency goes beyond drives. Looking at the five-game rolling average of the Celtics’ rim efficiency this season reveals a similar decline. This statistic calculates the average field goal percentage for shots at the rim over the last five games, smoothing out fluctuations:
Over the last 5 games, Boston’s rim efficiency has dropped to about 60%, far below last season’s average and this season’s league average. This decline isn’t just due to recent opponents. While the Mavericks and Rockets are among the best at defending the rim, the Lakers are one of the worst, and the Clippers and Warriors were missing their defensive anchors (Ivica Zubac and Draymond Green respectively).
Whether opponents are elite or mediocre defensively, they no longer open the floodgates and instead force the Celtics to beat them from three or mid-range. For example, the Lakers were comfortable letting Porzingis post up rather than doubling and opening a cutter. Opposing teams also seem willing to leave Jrue Holiday open, focusing instead on protecting the paint—a logical move, as Holiday is shooting below league average from three for the first time since 2020. And he’s not the only one.
Last year, during the playoffs, only Jaylen Brown shot below league average from three. This season, only Pritchard, Hauser, Porzingis, and White are shooting above league average. With opponents feeling less threatened by the Celtics’ shooting, the green army is struggling to capitalize on open looks.
Another indicator of spacing issues is the recent increase in long mid-range attempts. As defenses focus on protecting the rim at all costs, the Celtics are forced to settle for contested jumpers. Opponents are happy to let the Celtics take those shots, and Boston’s once-dominant offense seems to have stalled.
Overall, the problem extends beyond just drives. Opponents are prioritizing rim protection, leaving Celtics shooters open, and Boston isn’t punishing them as effectively as last year. Additionally, the Celtics’ offensive rebounding has regressed, with their putback efficiency dropping from 9th to 18th. Despite these struggles, there is untapped potential.
Untapped potential
From my perspective, two ways to improve the Celtics’ offense don’t require any roster changes. The first is to develop Kristaps Porzingis’ passing and his role as an offensive hub.
What if Kristaps Porzingis passing could open things up for the Celtics offense?
Among player with +20% Usage Rate, he has one of the lowest Playmaking Ratio (AST:Usg).
More on that soon, in the @celticsblog. pic.twitter.com/DkvmXujRhB
— azmatlanba (@azmatlanba) January 28, 2025
Porzingis has taken on a significant finishing role in the offense, but his impact as a creator could grow. His gravitational effect opens space across the floor. For example, in a clutch play against the Pelicans, Porzingis had the ball and scanned for cutting opportunities:
Jayson Tatum eventually received the ball on a cut after faking a handoff. Both Tatum and Brown possess immense off-ball gravity that could synergize with Porzingis’ on-ball presence. Yet, the Celtics rank 23rd in cuts this season despite being 5th in efficiency.
With Jaylen Brown struggling to score efficiently, leveraging Porzingis’ gravity could help him find easier scoring opportunities. Last year, the duo thrived off one another, producing highlight plays. This season, however, Porzingis has assisted Brown on only three rim attempts.
Whenever Brown and Porzingis are involved in actions together, it’s evident how impactful they could be. Yet, such plays occur far too infrequently. Another underutilized strategy is involving Jayson Tatum in pick-and-roll actions—on both ends of the play.
This season, Tatum is the only player to finish over 250 pick-and-roll actions as a ball-handler and 50 as the roll man. His off-ball ability and gravity are crucial for breaking defenses, and his on-ball scoring is equally potent.
Recently, the Celtics have paired Tatum with Luke Kornet or Kristaps Porzingis in pick-and-rolls, with both being highly efficient roll men. Among players averaging more than three pick-and-roll actions as roll men, Porzingis ranks second in efficiency—largely due to Tatum’s improved playmaking.
While some may consider the pick-and-roll outdated, it remains effective when executed with modern ball-handlers and elite rim-runners like Porzingis or Kornet. Adding this dimension could breathe life into the Celtics’ isolation-heavy offense and force opponents to adapt.
The Celtics are 11-10 over their last 21 games. During that stretch, they have the league’s 10th-best offense—far from last year’s dominance. Change is needed—will it come from within through Joe Mazzulla, or will Brad Stevens look to make adjustments from the outside?