Great start, still worried about the lack of size, which I believe has correlated to the drop in defense and is clearly responsible for the rebounding deficit (and it is nearly a 5 rebound swing from last year).
I think that you're right about a connection between size and rebounding, at least in general. Then, too, it's worth a look whether Boston really is smaller, not to mention what exactly it is we mean when we say there's a lack of size. Topics for another day.
What I want to address is how crucial it is to separate "rebounding" into its two parts, and why if you look at rebounding as a whole you can get a distorted idea about what's actually going on with a team; and in fact the Celtics are a perfect example of why this is so.
Offensive and defensive rebounding have distinct though overlapping skillsets; equally importantly, effective defensive rebounding is mandatory while offensive rebounding is a matter of a coach's preferences.
If you compare defensive rebounding between last season and this, they are almost identical:
This year, .776 - 7th in the league, which you'd have to agree is pretty good; last year, .773 - 11th in the league.
The difference is negligible, especially at this stage of the season. But it is important to recognize that Boston, if anything, is a slightly better defensive rebounding team than it was last year, at least up to this point. So saying that Boston is worse at rebounding up to this point is only true for offensive rebounding.
As I said, offensive rebounding is a different animal. Where defensive rebounding in the modern game is an extension of the team defense, building a point-to-point perimeter to prevent penetration ("five on a string" and all that), offensive rebounding is disruptive and chaotic; and while the defensive team has a natural advantage in positioning for rebounding - neutralizing some of any size disadvantage they might have - offensive rebounding favors length and lower body strength. In a shorthand, size.
So where do your 2023 Boston Celtics sit on the offensive rebounding rankings? It's tempting to get all melodramatic about it. Fallen off a cliff. Up the creek without a paddle. Gone to hell in a handbasket:
This year, .188, for 29th in the league; last year, .240, for 8th in the league.
I got all melodramatic; but in fact this year's Celtics actually are a mediocre defensive team, and (so far at least) are one of the historically great offensive teams. So whatever cliffs, paddles, or handbaskets you might invoke, the poor offensive rebounding does not appear to be consequential for the offense - in fact, it is worth asking if, at least in the case of the Boston Celtics,
not crashing the offensive board is contributing to winning.
Rob will certainly help with both of those, but I'm not sure he will make up the whole difference.
I agree. But I want to emphasize something I was pointing to earlier: how much offensive rebounding a team does is not just a function of personnel; some coaches would just prefer to get back down the court and stop their opponent's early offense. On a spectrum between maximum pressure on the O board and maximum change-ends-and-set-up-the-defense, Joe has placed Boston at the far end.