Defense doesn’t trend on social media. Nobody’s clipping a well-executed switch or a perfectly timed help rotation. But what the Boston Celtics are doing on the defensive end this season deserves more attention than it’s getting.
Historically Elite
A defensive rating of 102.3 would be the best since the 2003-04 Detroit Pistons posted a 98.7 — and that was in a fundamentally different era of basketball. Adjusted for pace and era, what Boston is doing is arguably more impressive. They’re holding opponents to this efficiency in an era where league-average offense is the most potent it’s ever been.
The gap between Boston’s defensive rating and league-average offense is 11.9 points per 100 possessions. That differential hasn’t been matched in over two decades.
The Switching Everything Philosophy
Boston doesn’t hide anyone. Their lineup versatility allows them to switch 1-through-5 on nearly every possession, eliminating the pick-and-roll advantages that power modern offenses. When you can’t create a mismatch, you can’t create easy shots.
The numbers back this up. Opponents are shooting just 34.1% on contested threes against Boston — the lowest rate in the league by a full percentage point. More importantly, they’re generating fewer open looks. Only 28% of three-point attempts against the Celtics are classified as “wide open” by tracking data, compared to a league average of 34%.
Depth of Talent
What separates this defense from past elite units is that there’s no weak link to target. Five different Celtics have a defensive win shares total in the top 40 league-wide. Opposing coaches can’t scheme around one player because the next man up is equally capable.
You can run whatever action you want against this team. Screens, handoffs, DHOs, Spain pick-and-roll — it doesn’t matter. They switch it, they recover, and you end up taking a tough two with six seconds left on the shot clock.
The Bottom Line
The Celtics defense isn’t just the best in the NBA this season — it’s tracking toward a historic mark that seemed unreachable in the modern game. In an era where everyone has spacing, everyone can shoot, and offensive rating records fall annually, Boston is proving that elite, switchable defense is still the most reliable path to winning basketball.
The 2004 Pistons won the championship with that defense. Boston has similar ambitions.