Three Stats to Watch After Hot Celtics Start

The Celtics rolled to a 3-0 start with wins over the Knicks, Wizards and Pistons that all featured 20-point leads. A near second half collapse revealed some cracks in Detroit, and Sam Hauser’s ongoing back injury tightened the team’s rotation.

Here are some other things to watch as Boston’s season continues against the Bucks… 

Boston allowing 1.3 points per possession in transition

The Celtics’ transition defense collapsed as part of their near meltdown in Detroit. As Joe Mazzulla usually says, the issues stemmed from poor offensive spacing, turnovers and bad shots. Boston missed eight layups in the third quarter, an easy way for the opponent to run the other way with advantages. The Celtics have only turned the ball over on 9.6% of their possessions so far (2nd), so that’s not a concern. They’re not shooting inside often, driving less often than any other team in the league, and converting at a 64% rate at the rim when they do. So something else is leading to leaky transition defense.

Adam Taylor pointed out the bad numbers and they shoot off the screen. Opponents have shot 63.7% eFG, the fifth-highest rate in the league, against the Celtics. Boston has fouled on 10.3% of those possessions. Last year, the Celtics allowed 1.05 PPP defending transition, the best mark in the league. The mistakes are all over the film from Detroit, and definitely worth watching against Giannis Antetokounmpo and the Bucks (72.2 eFG% in transition).

“It took us a little while to get acclimated to the speed of the game,” Mazzulla said in Washington.

15.7 isolation possession per game

The Celtics have played in isolation more than any team in the league to this point and have succeeded in doing so, posting 1.32 points per possession, which ranks fourth. Boston has scored 20.7 points per game in isolation and their reliance on it also shows in a relatively low assist rate (57%, 24th) following a preseason bump in passing (69.2%, 13th). Is it sustainable to play this way? Last year, the Celtics only isolated 9.9 times per game (4th) and their 1.01 PPP tied for fourth, with only 10.0 PPG coming from ISOs. In the playoffs, those numbers went down to 0.91 PPP, but their volume went up to 14.3 possessions per game, so Boston scored 13.0 PPG.

Matchup hunting is a big part of what the Celtics do, so big isolation numbers are here to stay, but over-dribbling and focusing too much on one matchup bogged Boston down in Detroit. Jaylen Brown, in particular, closed 1-of-9 in the second half and kept the ball stuck often. He’s posting 1.13 PPP, a solid number, while Tatum’s 1.54 PPP in isolation leads the league.

Late possessions where swing-swing passing led to back-to-back Jrue Holiday threes showed the Celtics able to move the ball around when necessary, but they’re playing in isolation at a heavy rate early.

Tillman-Kornet: -28.3 net rating in 21 minutes

With Hauser out, the Celtics went to double-big combinations with all four of their available centers in Washington before tightening the rotation in Detroit, leaving Neemias Queta with a DNP-CD. That led to nine minutes where Luke Kornet and Xavier Tillman Sr. played together, which Boston lost by 30.7 points per 100 possessions.

Isaiah Stewart’s activity on the offensive glass bothered them, and the Celtics’ 16.7 OREB% in that span, which would rank last in the NBA, defeats the purpose of playing bigger while dealing with whatever hindrances it creates guarding the perimeter and in transitions. Mazzulla has pressed the team to rebound better on offense to begin the year, and only ranks 13th (30.9%) in offensive rebounding percentage.

To his credit, Tillman Sr. has switched admirably onto the perimeter while playing heavy minutes at the four, but has allowed 55% shooting to opponents in his individual matchups. The Celtics’ double-big combinations have overall fared well, Al Horford and Tillman Sr. look good (+38.1), as have Kornet and Horford (+68.4), while Queta posted positive numbers with Tillman Sr. (+36.8) and succeeded with Horford last year (+23.3).

It’s not clear why Queta exited the rotation after a solid night in Washington, aside from some lingering defensive questions, while Jordan Walsh hasn’t broken through for meaningful minutes after a strong preseason. With Baylor Scheierman likely far from playing too, that creates a real depth question whenever an additional player is out alongside Kristaps Porziņģis. Especially at the wing. It’s also worth noting, while discussing the second unit, that Payton Pritchard has allowed 76.2% shooting to opponents through three games.

Mazzulla tightened the rotation into the second half against Detroit, playing Pritchard nine minutes, with Kornet and Tillman Sr. logging eight each.