Celtics early season stats: what the numbers say about the 2-4 start

Numbers never lie.

Early in the season, conclusions are far too easily leaped to. Only a handful of games into the Ime Udoka era, it’s too soon to write the narrative of this Celtics season. The eye test is hard to trust, with COVID repercussions and injuries preventing continuity within the lineup. Even the numbers are prone to being skewed thanks to statistical outliers, such as the 2-26 3-point shooting performance against the Washington Wizards on Saturday.

Instead of looking solely at what the numbers show about the Celtics’ performance, we can easily look at what they indicate about their process. Pay less attention to whether the shots are going in and more about how and where they are coming from.

When the narrative, eye test and data line up accordingly, the Boston Celtics will be a team in synergy. Speaking of synergy, we can use Synergy Sports Tech’s player tracking data to tell us more about the Celtics as a whole: where do their shots come from on the floor and by play type, where they are having success defensively and what the main premises of Ime Udoka’s system might entail.

Defense First

Make no mistake. This Celtics squad will be a team that is defense first. Both Robert Williams and Al Horford are worthy rim protectors; Williams is first in the NBA in blocks per game, while Horford just turned in a six-block performance in Timelord’s absence. The presence of consistent deterrence at the tin helps their backbone stay strong, even amidst stylistic changes towards a switch-heavy scheme.

It shouldn’t be a surprise that the Celtics are first in the NBA in defensive field goal percentage at the rim, allowing opponents to shoot a mere 50.3% within five feet. League average is hovering around 55%, and last year’s Celtics were at 56.8%. Time will tell if that number stabilizes, but the presence of multiple rim protectors should keep the Celtics as one of the better defensive units that close to the bucket.

Deterring and contesting shots are two separate concepts, though. The Celtics do a great job contesting and lowering the effectiveness of rim attempts, but they don’t do a great job of preventing them from occurring. One out of every three shots have come at the bucket, 19th in the league. In essence, allowing 50% shooting on 26 attempts per night equates to 26 points allowed at the rim per game.

That’s a stark contrast to the Phoenix Suns, who have been scored on a lot (65% at the rim) but give up the fewest rim attempts (17.2 per game). The Suns allow 22.3 points per game at the rim, fewer than the Celtics despite being more porous when teams get there. In recent memory, limiting rim attempts has been less of an indicator of long-term defensive success than effectively challenging at the rim. Four of the top five overall defenses last season finished top-ten in field goal defense at the rim. None of those same five finished in the top ten in field goal attempts.

One speculation as to why: defense is built as much around funneling away from the 3-point line as it is from the rim. Teams sell out on preventing easy catch-and-shoot looks, especially when they have a great rim protector behind the play. Williams and Horford give the Celtics effective interior defenders to funnel towards. Udoka is, in essence, betting that a contested rim attempt is better for Boston than an uncontested 3-pointer.

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The numbers back up such a claim. Through six games, the Celtics have given up 114 catch-and-shoot jumpers, according to Synergy. The 19 catch-and-shoot jumpers per game given up is the sixth-fewest in the league. For context, last year’s Celtics team gave up 22.3 catch-and-shoot jumpers per game, and the league-leading mark was 19.2 by the Utah Jazz. That’s right: this Celtics team is currently undercutting the historic Utah Jazz defense from last season and giving up fewer spot-up looks.

Again, the sustainability of that number remains to be seen. But the most effective defenses from the last several years have been those who limit easy looks from deep and force a high volume of dribble jumpers. Right now, just 29.3% of all shots the Celtics give up are off-the-dribble jumpers, fifth-best in the NBA. Last year, only three teams forced more than 26% of their shots to be dribble pull-ups, and all three (Utah, Los Angeles Clippers and Milwaukee Bucks) finished with a top-ten defense.

Right now, the Celtics are 19th in overall defensive rating. Teams are making shots against them and there are tweaks that can be cleaned up with the mechanics of how to operate within Udoka’s switching scheme. But the numbers indicate a really strong defensive process put forward by Udoka, one that is forcing opponents to take the right shots for Boston.

The Other End

If a good defense takes away rim attempts and catch-and-shoot jumpers, it would stand to reason that a good offense finds ways to generate those looks frequently. In some ways, the Celtics are succeeding by this measure, and in others, they are not.

Take the bad first: the Celtics are 27th in producing shots at the rim, with only 28% of their field goal attempts coming within five feet. From a narrative perspective, this one is easy to understand: Jayson Tatum and Jaylen Brown, the two leaders of this offense, are both jumper-heavy scorers. Tatum has taken far more dribble pull-ups (56) than shots at the rim (36) on this young season. Brown (26 pull-ups, 21 rim attempts) is much more balanced.

Without their top stars putting pressure on the rim, two effects happen. The first: fewer shots at the rim will take place for the Celtics. That one is pretty evident. The second — and far more concerning on the whole — help defenders stay closer to their man, knowing the Celtics won’t put pressure on the rim, and therefore, give less space for quality catch-and-shoot looks.

Somehow, the Celtics offense is still creating a great deal of uncontested catch-and-shoot looks, defined by Synergy as an attempt that occurs without a defender within four feet. 60% of Boston’s catch-and-shoot looks have been uncontested, the sixth-highest across the NBA. As shooting balances back to equilibrium and the Celtics make the shots they’re getting, this offense should start humming.

Right now, the Celtics take 33% of their shots as catch-and-shoot looks, the sixth most in the league. While the dribble jumpers are still a tad high, that’s due in large part to the engines driving the offense (Tatum and Brown) and not with schematic flaws or poor emphases on shot selection by Udoka.

Photo by Brian Babineau/NBAE via Getty Images

During Monday’s pregame presser, Horford spoke about figuring out the right balances of the offense and what might provide a solid fix. “I think we’re still a work in progress offensively. I think the whole thing is to play with [Saturday’s] pace,” said Horford. Pace has a lot to do with aiding in their ability to put early pressure on the rim and avoid stagnant late-clock situations. The Celtics take the eighth-most shots in the final four seconds of the shot clock. An added injection of pace could solve those issues.

Bottom line, it’s early. It’s far too soon to be looking for the panic button, let alone pressing it. The shots will fall, small tweaks will be made and the players will find comfort within new roles or a new system. From all the numbers can point to, the Celtics are getting the right types of shots on both ends despite their constant lineup fluctuation. Udoka has them playing a successful brand of basketball.