Profitable the margins: who drives the Boston Celtics’ possession edge?

Joe Mazzulla typically talks about his willingness to “dominate the margins and dominate the possessions.” However how?

The general public typically focuses on offensive rebounding when speaking in regards to the possessions battle. But, there are three different levers to this battle: defensive rebounding, forcing turnovers, and taking good care of the ball. As a result of this possession battle appears to develop into an increasing number of vital, why not have a look at who’s one of the best at it? Who has essentially the most affect on the possession battle on a basketball courtroom?

This concept got here after studying Owen Phillips’ wonderful piece on the “Turnover Financial system.” I needed to dig deeper. What if we checked out this query from a extra particular person perspective—and included each turnovers and rebounding?

Utilizing 2024–25 on/off knowledge from Cleansing the Glass, I attempted to estimate how gamers impression the variety of possessions their groups achieve or lose—each on offense and protection—after they’re on the courtroom.

To take action, we want key metrics:

• OFF POSS ADD (offensive possessions added) = (ORB% × 0.533) – TOV%

This tries to estimate what number of additional possessions a participant creates on offense, by grabbing offensive rebounds and limiting turnovers. The 0.533 issue comes from this season’s common miss price—so it scales offensive rebounds to precise additional shot alternatives.

• DEF POSS ADD (defensive possessions added) = Pressured TOV% – (Opp ORB% × 0.533)

This estimates what number of additional defensive possessions a participant’s workforce features because of their capability to pressure turnovers and safe the rebound after a missed shot.

• TOT POSS ADD (complete possessions added) = OFF POSS ADD + DEF POSS ADD

That’s the sum of each, giving a tough concept of how a participant shifts the possession steadiness per 100 possessions performed.

The rationale we’re utilizing on/off knowledge is to keep away from the bias of focusing solely on particular person efficiency and reasonably have a look at the affect a participant has on workforce efficiency. An awesome instance of why particular person rebounding metrics are biased is Andre Drummond. Regardless of being seen as the most effective rebounders of all time, his groups have been typically higher at rebounding when he was off the courtroom.

The possession battle is a collective effort, and that’s why on/off statistics give us a greater sense of particular person affect. But be aware that on/off additionally has its personal biases—akin to who’s on the courtroom with the participant or who his backup is. No metric is ideal, however let’s dive into the numbers and attempt to perceive who’s one of the best Celtic at including possessions on offense and protection.

A two means avenue

Whereas some groups, just like the Houston Rockets, are attempting to win the possession battle from the soar until the top of the sport, the Celtics appear to have one other method. Trying on the knowledge, the Celtics seem cut up into two completely different groups.

Within the backside left, yow will discover all of the starters. The gamers in that a part of the chart are those much less prone to have helped the workforce win the possession battle this season. On the opposite aspect of the road that cuts the chart in two, yow will discover all of the gamers from the bench who performed greater than 300 minutes.

Watching the video games, there was a transparent feeling that with Luke Kornet and Payton Pritchard on the ground, the Celtics have been crashing the offensive glass much more. However this two-way method to the possession battle goes past that. On each offense and protection—by means of rebounding and turnovers—the Celtics have been extra intentional about successful the possessions battle with the bench unit than with the beginning 5. Why?

Profitable the possession battle typically comes from groups who lack offensive firepower or capturing, just like the Houston Rockets. Due to this fact, it is smart that the Celtics’ bench confirmed extra willingness to struggle and create extra possessions to compensate for the extra expert gamers resting. However the offensive construction of the beginning 5 additionally had an affect.

Certainly, essentially the most influential gamers within the possession battle are sometimes facilities. Their measurement impacts rebounding, and the bottom they’ll cowl influences the flexibility to generate turnovers. Due to this fact, with Kristaps Porzingis spending most of his time on offense past the three-point line, it is smart that the Celtics’ beginning 5 is much less prone to generate additional offensive possessions. Nonetheless, what’s extra fascinating—and will have foreshadowed the Celtics’ struggles towards the Knicks—is the beginning 5 underperforming on protection by way of producing additional possessions in comparison with the bench.

It’s no secret that the Celtics misplaced towards the Knicks partly as a consequence of their incapability to guard the glass and their struggles within the margins. Nonetheless, over the course of a full season, are the Celtics who assist win the possession battle additionally those who assist win video games? Effectively—sure and no.

Is successful the possession sufficient?

For many who learn loads of my 10 takeaways and tactical deep dives, it received’t be breaking information that the Celtics have been at their greatest with Kornet on the courtroom. As we see on the chart under, the Celtics’ backup large man was on the ground when Joe Mazzulla’s workforce was successful the margins—and the scoring differential.

Additionally, some gamers have been nonetheless extremely optimistic regardless of not performing significantly effectively within the possession battle—akin to Derrick White or Jayson Tatum. There have been additionally gamers who helped the workforce dominate the possession battle however weren’t as impactful on internet score, like Pritchard or Neemias Queta. After which, there are three gamers who underperformed in each: Porzingis, Jrue Vacation, and Jaylen Brown. Over the course of the season, the Celtics have been extra prone to win the possession battle and have a greater internet score when these three have been on the bench.

Total, this reveals that the Celtics have been in a position to play two types of basketball: the five-out spacing with the starters, and the gritty possession battle with the bench. And once you combine all of it, you find yourself with an awesome common season. This additionally demonstrates that successful the possession battle is vital—however not at all times sufficient to win. Additionally, be aware {that a} participant’s impression on the possession battle relies upon closely on context and function optimization. At present, Kornet is among the greatest gamers at serving to his workforce win that battle. Earlier in his profession, in a distinct context with completely different assignments, he was one of many least impactful gamers on that finish.

If you wish to learn extra in regards to the possession battle throughout the NBA, be happy to take a look at my latest Twitter thread on the subject: