BOSTON — Jayson Tatum saw his early season reality in front of him when O.G. Anunoby plucked an offensive rebound out of Tatum’s hands and floated a layup back in over his head before the Celtics star’s ejection concluded his preseason on Friday. Tatum shrugged off the incident at practice on the eve of his sixth NBA season, one that’ll see him return to the four position more often than last year, needing to bang for boards, block shots on the weak side and defend burlier opponents.
The Celtics allowed a league-high 17.3 offensive rebounds per game in the preseason, a harder problem to ignore. Mason Plumlee barreled through Boston’s front line, Kelly Oubre followed shots and Anunoby outmuscled Boston’s wings as one of four Raptors with three offensive boards in the finale. Toronto totaled 22 in Friday’s game and scored 18 second-chance points, a low conversion rate that shows why rebounding isn’t the end of the world, but not an area the Celtics can afford to be the worst in the league at if they’re going to rely on shooting and play in close games. Australia’s Adelaide 36ers and Israel’s Maccabi Ra’anana allowed fewer offensive rebounds per game in preseason NBA competition than Boston. The Celtics finished 32nd overall.
“Anytime you’re not fully healthy, the accountability is stretched a little bit. Everybody has got to do a little bit more. I think it’s getting used to the fact that we’re not big right now, and how can we be great at that?” Joe Mazzulla said. “I think it’s just on all of us to figure that out. It goes into the matchup, do I feel like we matchup well on both ends of the floor? I think last year we thought defense first, and obviously you have to do that, but now I think with our skill we can think offensively as well, so just a little bit more balanced and what gives our team the best opportunity to win.”
That offense flourished, sending the ball floating across the floor between five ball-handlers and shooters to lead the league in three-pointers made (19.0) and attempted (49.3) on 38.6% efficiency, setting another standard with 31.0 assists to 18.5 turnovers. Jaylen Brown and others raved about the space they played with, and both he and Derrick White, who started all four games, combined to shoot 60% from the field on 83 attempts.
Mazzulla entered his interim role intent on making a Celtics offense that stalled in the preseason more dynamic, but so far they’ve struggled to balance that against maintaining their defensive identity from last season. The team rarely got to experiment with double big lineups, with an early practice look including Luke Kornet never appeared in the preseason after Kornet injured his ankle. Blake Griffin mostly filled backup five minutes, still getting acclimated to the team’s defense alongside Mfiondu Kabenegele and Noah Vonleh. Mazzulla indicated this week that those bigs need continued repetitions to show they can execute the defense.
“(Rebounding) really hurt us, so we need to be better in that area collectively. That’s something that we’ve addressed and we’re looking to make up for it as a group. Different guys have to step in and we all have to get in there and get rebounds. For me, it’s all about how we’re playing,” Al Horford said. “Sometimes, wins and losses are obviously the end results, but the way that I see it is, I want to see how we’re looking, how we’re feeling on the court, how guys are getting along, how we’re starting to develop. I want to be able to see Luke get out there and move with us and play with us and different guys that have been in and out. I feel good about our group and what we have here. We just have to continue to build it day by day.”
In the absence of those big men, the Celtics played as small as having Sam Hauser and Tatum stand as the tallest player on the floor, forcing Grant Williams to return to a primary rebounding role after mostly roaming the perimeter last season. The same can be said for Smart, White and Brown, who all posted their highest career rebounding percentages multiple seasons ago. Tatum, who averaged 10.0 rebounds per game in the 2019-20 playoffs, becomes as important as Horford (22.2 DREB%), who posted his highest rated rebounding season since 2012-13 last season. Reducing Horford’s burden on the glass will prove key to limiting his overall load.
Joel Embiid looms on opening night, who finished 30th in offensive rebounds last year and presents an imposing first matchup overall for a smaller front court. Grant guarded him effectively at times last year and Horford fared as well as anyone in basketball in recent seasons. Having two bigs play such important point of attack defense against top opponents, while potentially switching to the perimeter often in last year’s scheme, all while three guards surround them on the floor, underscores the need to attack the boards collectively.
That may limit some of the team’s transition ability, but maintaining last year’s historic defense and turning misses into makes required at least average defensive rebounding (72.5 DREB%, 16th). The top teams in defensive rebounding percentage (Denver, Milwaukee, New Orleans, New York, Utah) didn’t see rebounding create wins, but the worst ones (Detroit, Clippers, Minnesota, Charlotte, Brooklyn) had disappointing seasons, in part, because of their inability to finish stops.
“I’m like the tallest guy out there. I think that plays to our strength, playing fast,” Tatum said. “Anybody can get the rebound and push it, even Al, and we know that. So when the shot goes up, we get the rebound, nobody’s necessarily waiting in the back court to get the ball. We all push it ahead. We all could attack … get the ball and go … we don’t have any room for error on that end. When the shot goes up, everybody gotta attack the glass, even if you’re boxing somebody out. You’ve gotta do your jobs, somebody else gotta go get the boards. Just being aware of that, whatever lineup is out there doing that. We’re not the tallest team right now without Rob, so everybody gotta get in and gang rebound.”