Why Celtics Still Allow Too Many Threes When Kristaps Porzingis Plays

Kristaps Porziņģis’ return from missing nine of the Celtics’ last 10 games served as a reminder of his ability to submit earth-shattering offensive performances — even at half-speed. He played the full fourth quarter, nearly one month removed from his last appearance, and shot 8-of-9 on two-pointers.

But Brooklyn, on the other end, kept pace on the other end, hitting seven threes in the fourth as part of a 20-for-46 explosion by a team that only attempts 38.9 triples per night and converts 34.6% (25th), raising questions about Boston’s lineups that feature him at center.

The Celtics’ opponents have shot 3.5% better compared to when he’s off the floor, a swing that ranks in the 8th percentile among NBA players. Boston is giving up above the break threes (+5.2%) when he plays, but his paint presence on defense allowed the Celtics to shut off the rim (-7.9%) and corners (-2.3%). With three-point variance able to swing games drastically, Boston will need to strike a balance between Porziņģis’ strengths and weaknesses.

“I don’t think it’s about preventing (threes) as much as it is having an understanding of personnel, time-and-score, situations and things,” Joe Mazzulla said on Tuesday. “Just have to be great at multiple defenses and multiple lineups, continue to have the versatility that we need and winning on the margins and being as physical as we can regardless of lineups or coverages … they’ve done it, it really just depends on who gives us the best chance to win each game, each segment that we’re in, best lineups, all those things.”

The Nets, like others, found success attacking Porziņģis from outside, and when he lost Ziaire Williams in transition, who hit a three to pull within 112-108 with one minute left, Mazzulla threw his hands up exasperated along the sideline. Williams shoots only 31.4% from deep in his career. That became 7-for-14 across the the home-and-home with Boston with Porziņģis mostly stashed on him.

Over a 10-6 stretch in January, the Celtics allowed 35.6% shooting to opponents from deep, which fell to 15th in the NBA. Porziņģis played in all but three of those games, and noticed the droves of career nights happening by Boston’s opponents against him, including Dillon Brooks shooting 10-of-15 from three, Dejounte Murray going 6-of-9 in a near upset and Julius Randle going off for 5-of-7 while the Celtics tried to sell out on Anthony Edwards.

“The luck hasn’t been on our side for the most part of the season,” Porziņģis said in January. “I just saw a tweet also of the amount of players that have set their 3-point records just this year, just 2025. So I think at the end, everything will even out a little bit and we’ll go on a nice run.”

Porziņģis deserves some grace for the layoff he endured alongside the offensive weight he carried in the win with multiple starters out. It started in an unfamiliar lineup that featured rookie Baylor Scheierman, who got lost multiple times in rotation. When Porziņģis missed Boston’s first 17 games, the Celtics devolved into one of the worst teams at protecting the rim in the NBA (68% FG, 23rd). Since, they’re the best in basketball (61.9%) while managing the three-point line at 35.1% (7th) and ranking second in defense overall (110.1 def. rating).

Al Horford presents a trade-off in certain matchups, though, and one that allows the Celtics to far better patrol the perimeter. Boston’s opponents shoot 4.5% worse from three with Horford on the floor compared to off, which ranks in the 94th percentile of player impacts. The above the break threes, in particular, come back to earth (-5.4%) with Horford out there, though the Celtics allow 5.6% better shooting inside with Horford not providing the rim protection that Porziņģis does.

The solution? They’ve played both often this year: a combination that boasts a 117.0 offensive rating (2.1 pts worse than Boston’s overall) and a 110.3 defensive rating that’s the same as the team’s for a +6.6 net rating. Last year, the Celtics finished with a +13.0 net rating in that double-big look.

“We don’t want to give up threes to anybody,” Porziņģis said after the Celtics held Brooklyn to 28.9% 3PT on Tuesday. “But most of the time, I’m guarding somebody that’s a non-shooter, so just have to be mindful of who we’re guarding and closing out and I think today, too, we could’ve done a better job, myself especially, on some of the close-outs. We did a better job than in the first game, but can still improve.”

The double-big lineup, which started Tuesday’s win, holds the line with opponents shooting 35.4% 3PT, while Porziņģis’ solo minutes saw them shoot 39% from deep and Horford’s held them to 31.9%. That’s a larger gap than last year’s splits, which were closer to 36% with Porziņģis, 31.8% with Horford alone, implying some bad shooting luck coming into play this season. Mazzulla typically monitors shot quality and changes matchups in-game. Thunder coach Mark Daigneault praised the Celtics’ ability to do that as one of their strengths that keeps opponents off-balance.

Mazzulla also carefully assesses league trends. Teams are shooting 2.4 more threes this year, something many around the league expected as an answer to the Celtics’ title run, but Boston noticed that in selling out to take away the three earlier this year, opponents caught fire over smaller sample sizes. However unintuitive, allowing more three-point attempts gives the shooting a chance to regress to the mean. It did since February began, Boston’s opponents down slightly to 34.3% since February. A sign of the randomness of that number: they shot 37.4% (21st) in the eight games Porziņģis missed recently with an illness (Horford missed two of them as well).

“Obviously, I have my rim protection, which is a part of my game that I need to keep,” Porziņģis said. “But I want to improve the rest of the things, and sometimes that is getting out more and being just a little bit closer to the shooter here and better contest here, and being in a better position there. These little things I can keep improving to become an even more complete defender.”

While all this noise doesn’t necessarily reflect on Porziņģis individually as it does the team defense the Celtics run, Mazzulla and the coaching staff have challenged him since the day he arrived to become more impactful on the defensive end. They’ve switched him more than ever before, forced him to communicate matchup changes and calculated risks on the fly, and this year, Boston attempted to force more turnovers — another adjustment.

There’s a chance the Celtics force him to defend the perimeter more when the games matter this postseason, but his relative absence from the playoffs one year ago serve as some reminder of just how little he’s played with his Boston teammates compared to the rest of them. They rode Horford’s defensive identity to the title last summer. This year, they’ll need Porziņģis to develop his own.

“That’s one thing I’m looking always to improve,” Porziņģis said. “Learning from a guy like Al, who’s switching on-through-five and is one of the best defenders on our team, honestly. He has a lot of little tricks that he does, and a little this, this and hold a little here and they don’t call it. Al is so smart and anticipates things so well, that’s somebody I watch and try to learn from.”