Bold claim: the Celtics’ summer transformation reshaped the NBA landscape in a single off-season. In Washington on Thursday, with 9:13 left, Anfernee Simons curled off a Neemias Queta screen, rose up, and buried a three to put Boston ahead 122-88, a 34-point cushion. Moments later, Hugo Gonzalez tracked CJ McCollum full-court, underscoring the Celtics’ new defensive identity in a snapshot.
Joe Mazzulla pivoted the defensive approach this summer as the front office retooled the books. The blueprint that powered back-to-back 60-win seasons and a title would no longer suffice. The plan: a complete, 180-degree shift on defense. “For the past two years, since I’ve been here, we’ve sat in our shifts, let them play one-on-one defense, not really helping much,” Jordan Walsh explained after DC. “Now this year, it’s all about helping the other guy out.”
Instead of relying on elite individual defense and a tolerance for fouling, Boston is now a swarm. The moment a ball-handler looks away, the Celtics converge. It’s been chaotic at times, a work in progress, driven by an unlikely quartet.
Jordan Walsh, Hugo Gonzalez, Josh Minott, and Baylor Scheierman form what you could call the Four Horsemen of the Celtics’ new defense.
Celtics’ new defense, a game-changer
In Washington, those four combined for eight steals and blocks. Each player moves with distinct speed and style, yet all contribute to Boston’s overall scheme.
“We executed the game plan well,” Mazzulla said after the 146-101 demolition of the Wizards. “Their energy and attention to detail were evident. The ball pressure was relentless, which collapses spacing and creates opportunities to make plays. Everyone who played contributed.”
Defensively, Boston’s metrics aren’t dazzling across the board. They sit 16th in defensive rating (115.0) but now surrender the third-fewest points per game in the league (110.7), trailing only the Oklahoma City Thunder and Houston Rockets in opponent points.
The Celtics embrace calculated risk: relentless ball pressure and aggressive help, even if that means conceding a kick-out three when the contest is strong. “We’ll live with a kick-out three if we can get a good contest,” Walsh said. “We’re not living in the paint, for the most part.”
That philosophy has yielded some punished nights. In six of their past ten games, opponents shot 40% or better from three, and three times reached 45% or more. Boston has still gone 6-0 in those games.
Math drives the defense
Like the team’s offense, the defense is guided by numbers. The Celtics contest the fewest shots per game (85.3), even while ranking among the league’s worst in offensive rebounding (12.5 per game). The strategy hinges on pressure, pressure, and more pressure—living with late threes if they contest them vigorously.
Their high-risk, high-reward approach has produced turnover-friendly chaos. If Minott snags a passing lane and misses, the next teammate is ready to rotate. If a pass makes it through, another rotation comes. Corner help blocks are a staple of the scheme thanks to constant rotations.
The overhaul began in the off-season. “For the last few years, it was mostly one-on-one. This year, all five guys are connected,” White noted. “We’ve been building toward this all summer—a shift toward flying around, hunting for turnovers.”
The defense requires collective effort
The plan is simple in theory: if one defender risks, others cover. If a mistake is made, a teammate is there to help. In practice, it’s hard to execute. Walsh acknowledged the challenge of translating concept into action: “It’s easy to learn, hard to do.” The near-complete roster turnover helped—rebuilding the defensive foundation from scratch made the transition smoother.
Walsh’s emergence as a rotation staple stems from his defense. He’s chased opponents like Tyrese Maxey, James Harden, and Donovan Mitchell full-court. Scheierman, Gonzalez, and Minott have joined him in the same aggressive pressure.
“Everybody’s picking up full-court,” Walsh said. “The pressure is at a different level now.” That’s exactly what Mazzulla wants.
“Everybody’s being asked to contribute,” Scheierman added. “I’m getting more comfortable with the full-court assignment and the energy it creates when the ball swings to me.”
Pushing 94 feet is only the start for Boston
If a star driver picks up the dribble, the Celtics collapse in. If a ball-handler wavers, they pounce. If a ball rolls out of bounds, Scheierman, Walsh, Minott, or Gonzalez hits the floor to disrupt the play.
Gonzalez has chased blocks and saved points, sometimes colliding with the stanchion, in pursuit of momentum-changing plays.
Each steal, block, and hustle feeds a self-sustaining energy loop: disruption begets more disruption, which fuels teammates and unsettles opponents.
“Momentum begets momentum,” Walsh said. “A steal here, a disrupted possession there—it's contagious. The team rides the wave and opponents feel it.”
Boston’s offseason was about radical change in pursuit of winning. The team said goodbye to stalwarts like Jrue Holiday, Kristaps Porzingis, Al Horford, and Luke Kornet. The Celtics could have kept the old defensive playbook; instead, they burned it to the ground and rebuilt.
Mazzulla didn’t just adjust; he reshaped the entire defense. Walsh, Gonzalez, Scheierman, and Minott rose from the ashes to spearhead the transformation.
