How Much of a Concern Should Rebounding Be for the Sixers?

Even though the Sixers have earned their praise for an outstanding summer of 2024, they don’t view themselves as a finished product just yet.

Daryl Morey never likes to proclaim that his team has achieved its full evolution before the season starts. He tries to spare a roster spot for a large chunk of the regular season, keeping some room reserved for opportunities to solve problems as the campaign goes on.

In some cases, the problem reveals itself as the games are played. Trends develop and stand out.

In other cases, the roster construction has such an obvious flaw that conjecture can be raised ahead of time.

In the case of the 2024-25 Sixers, the President of Basketball Operations was ready to suggest a weakness as early as July.

“If we lose next year, rebounding is going to be the issue,” Morey said on a recent episode of Rights To Ricky Sanchez. 

“At least the one that we can spot. Usually, you have the unknown unknowns that wack you sometimes, too. But, the known issue going in for sure is going to be rebounding.”

That supposition opens a line of questioning. Rebounding might be an issue that is identifiable ahead of time, but all of these diagnoses are relative. 

How will a rebounding issue for this group compare to a rebounding issue for last season’s team, especially considering one might argue that rebounding was the reason the Sixers lost to the New York Knicks in the first round of the 2024 playoffs? How does this year’s team project to rebound the basketball compared to the team that just won the championship? How do the players’ capacities to rebound compare to those of their respective positional averages?

The numbers

Let’s start with the averages for each position in 2023-24, according to Cleaning The Glass (CTG):

I prefer to look at some statistics as rates rather than as plain box-score lines. Forget rebounds per game or even rebounds per 36 minutes. How often did the position corral the missed shot when it was on the court?

The table above approximates that rate for each position, as defined by CTG, in the 2023-24 season.

Let’s look at how the 2023-24 Sixers graded:

The standard the Sixers are hoping to set entails parades, trophies, and banners. The only team worth measuring them against, then, is the 2023-24 Boston Celtics:

Now that we know how the champs fared, let’s try to project how the Sixers will rebound in 2024-25:

The data set can’t possibly be a perfect estimate because there are three players on the roster who can’t be included in the table. Guerschon Yabusele figures to have a real shot at making the regular rotation. His rebounding for Real Madrid this past season cannot be measured as a percentage, but rather as a per-36-minutes rate courtesy of Basketball Reference, because CTG specifically works with NBA data. The same is true of the data for rookies Jared McCain and Adem Bona, who figure to have less playing opportunity if any at all at the NBA level this season.

Even though it is not the same playing field as the data displayed in the tables above, here’s what Philadelphia is looking at with those three newcomers:

What the numbers say

None of the data is perfect. There is sample size variance in each table. The rosters are uneven and thus the averages are on different scales. The 2024-25 Sixers projection merely plugs in each player’s 2023-24 rate and assumes no variance because we can’t know what to expect. None of it accounts for team schematic differences or how players on the 2024-25 Sixers might act when the shot goes up compared to how they did in the past. We had to build a separate table using an entirely different metric for three new players because there was no prior year NBA data to use.

But, it’s what we have to work with.

The 2024-25 Sixers project to be a better defensive rebounding team than the 2023-24 team was, and by about 16 percent at that. They still pale in comparison to the team that brought Boston its 18th NBA championship this past June.

I think the most jarring observation we can make is that Drummond’s offensive rebounding rate was 255 percent higher than Embiid’s was in 2023-24. His defensive rebounding rate was 139 percent better. Drummond projects to be by far the best rebounder on the team. His specialty will hardly matter beyond the games that Embiid is not available because he’s likely going to be playing less than 20 minutes per game anyway. Unless Drummond suddenly starts stretching the floor in a way that defenses have to respect (that’s not going to happen), he and Embiid aren’t going to log minutes together.

None of that is to suggest Drummond is an overrated rebounder. He’s arguably the best rebounding big in the entire league. He will dominate the glass in his minutes. The problem is the quantity of those minutes. 

The numbers also show a troubling comparison within the 2024-25 Sixers’ roster and the title-winning Celtics.

Boston had just two players who finished with single-digit defensive rebounding rates. Neither were rotation players. The Sixers figure to have four players in the single digits. All four will likely be rotation players, at least in the regular season.

Beyond that, Boston had a more consistent range of offensive rebounding rates than the Sixers project to have. While the Sixers have a strong outlier, they also have a roster riddled with players who project to have offensive rebounding rates in the 1-2-percent range. Whereas the Celtics had clusters of players across a couple close ranges, the Sixers are in danger of having clusters of their roster across a wider spectrum of offensive rebounding rates.

In other words, there was depth in Boston’s offensive rebounding prowess. That depth does not exist across the 14 players on the new-look Sixers.

What basketball theory would say

It’s logical to expect the Sixers to outperform those projections for two reasons. 

First, their perimeter defense should be far deeper than last season’s was. That means less dribble penetration, less need to contain the ball, and more leverage for Embiid to stay closer to the basket on defense. As long as he or Drummond is able to linger around the rim, Philadelphia should put up fine numbers on normal misses.

As for longer misses, the improved length on the perimeter should help corral those rebounds. However, rebounding long misses is as much about will and mindfulness as it is about intangible gifts.

Second, Philadelphia’s first-shot offense should be so good that there won’t be a significant market of offensive rebounds to tap into. There will be off shooting nights. The Sixers will have to play a dirtier brand of basketball from time to time. But, by and large, they have the talent to post an elite first-shot offense. If the first shot goes in, no need for a second-shot offense.

There are still concerns, though. The guard rotation is small and on the older side of the age spectrum. There will be a price to pay for creating lineups that have shooting and ball-handling, even if the rest of the unit has the size to be highly capable on defense.

There will be a price to pay for favoring Drummond’s rebounding prowess in drop coverage in the playoffs, when switching is more a requirement than an option. Drummond is not adept at guarding in space. So, there will be a poison to pick. Do you stay in drop to leverage his rebounding capability, or do you take him out of the game and make yourself weaker in an already vulnerable department?

These are concerns the Sixers will have to think about as the season goes on. No team is perfect at the first jump-ball of the season. As great an offseason as the Sixers had, Philadelphia is certainly no exception to that truth.