From the Celtics’ first game on December 23rd through the end of February 2021, the team held their opponents under 100 points a total of four times. In the months of March and April, they’ve done it six times, five of which came after the trade deadline. After splitting a back-to-back against the Phoenix Suns and Brooklyn Nets, the Celtics hold the 3rd best defensive rating over their last 15 games.
The narrative all year has been the Celtics weren’t playing with energy and urgency. Maybe that’s true, but I don’t think a change in energy is the main cause Boston’s defensive revival. Splitting up the Thompson-Theis starting lineup was necessary to unlock the rest of Boston’s defense and I’ll do my best to elaborate on this, starting with this video:
Here we have Marcus Smart sticking to Devin Booker like glue, Kemba Walker taking charges, and Romeo Langford blocking shots. Did these things just magically become possible? I suppose Romeo is somewhat of a mythical being, but having him—or any other wing—replace a lot of Theis’ minutes is a key component to the defensive shift in recent weeks.
More to the point, the Celtics had one main problem they needed to solve: getting killed by perimeter shooting. How many games did the Celtics get lit up in the first quarter by three point shots with the double-big starting lineup? And sure, it’s happened a couple times within the most recent winning streak, but the defensive stats over that span speak for themselves.
Promoting Robert Williams to the starting center role has been a boon as well, so what do you get with him and Romeo playing more? Length, speed, passing, and in Rob’s case, a potent scoring threat at the rim. With all due respect to Daniel Theis, who happens to be one of my favorite role players of all time, but there’s nothing that he did that the Rob-and-a-wing duo can’t replicate.
There’s more benefit to the lineup change than simply not giving up a ton of threes. If the opposing offense can’t get every perimeter shot they want by abusing slow defensive rotations, they’ll look to drive the ball instead. This is the difference between Devin Booker shooting a dozen threes and committing four offensive fouls.
If you still don’t think taking charges is a skill, then take note of the difference between games played here. Blake Griffin, Kyle Lowry, and Kemba Walker have played between 34 and 41 games, making up the top three spots. Montrezl Harrell has drawn as many charges as Walker and Lowry, but it took him over 20 more games to do it. Do you think these drawn charges just materialize out of thin air? Or is there a reason some players can accumulate them at such an accelerated rate compared to the rest of the league? It’s not always the most compelling basketball, but you can’t deny it as a real skill.
The question, as always, is about sustainability. The defense has mostly held up with Robert Williams missing a couple games, which is a great sign moving forward. Tristan Thompson was targeted pretty heavily against the Brooklyn Nets, but that’s not a weakness I expect to be relevant until the playoffs. The Celtics have one of the easiest remaining schedules, which should bode well for their pursuit of the fourth seed.
Also of note: the Hawks, Hornets, and Heat all have relatively easy schedules the rest of the way.
Among Boston’s remaining opponents, the Knicks are ranked 21st in offensive rating. The Heat are ranked 24th, the Timberwolves are 26th, the Cavaliers are 28th, and the Magic 29th. The fourth through eighth seeds in the East are within 3.5 games of each other, with the Celtics narrowly in sixth. Given the schedule, they have a strong chance to grab home court in the first round of the playoffs.