The Boston Celtics can halt the Cavaliers undefeated start to the season.
The Boston Celtics will play their first big game of the season when they face the Cleveland Cavaliers tonight. Kenny Atkinson has led last season’s Eastern Conference semifinalists to a 15-0 start. Joe Mazzulla’s team will be looking to end that run and claw a game back in terms of seeding.
Let’s examine the stats behind the Cavs and see what makes them tick on both sides of the floor.
Cleveland: By the numbers
The Cavs currently lead the NBA in offensive rating, averaging 122.1 per 100 possessions. They sit directly ahead of the Celtics, who average 121.6. Interestingly, the New York Knicks sit third, with 121.1 per 100. That means, right now, the best three offensive teams in the league all reside in the East — which illustrates the improvements made by some of the Celtics biggest threats this season.
On defense, Cleveland is 7th in the league, holding teams to 110.7 points per 100. Boston is 9th, with opposing roster’s averaging 111.2 per 100. With such a small variance, both Cleveland the Celtics can be expected to have stretches of elite defense. Although, as we all know, Mazzulla’s team is yet to find it’s top gear on that side of the floor — especially when limiting penetration or guarding in transition. We can talk about rebounding a little later, too.
When taking a step back and judging both teams based solely on their offensive and defensive ratings, it’s clear that they’re evenly matched. Not in terms of talent but in terms of the production we’ve seen from each franchise to begin the season. The Celtics will have their work cut out for them if they want to secure a win on their home court and even up their NBA cup record at 1-1.
Still, there’s a lot more we can learn. Let’s start peeling off some additional layers. All data, unless stated otherwise, is courtesy of Cleaning The Glass.
Offensive Shot location frequency
This is where Cleveland’s offense is coming from and how frequently they look to attack those spots. The higher the league ranking, the more frequently the Cavaliers are attacking those spots vs. other teams in the league.
- Around the rim – 36.9%, 5th in the league
- Mid-Range – 23.4%, 27th in the league
- Short mid-range – 16.1%, 27th in the league
- Long mid-range – 7.3%, 15th in the league
- 3-Point range – 39.7%, 12th in the league
- Non-corner 3’s – 27.8%, 15th in the league
- Corner 3 – 12%, 7th in the league
Offensive Shot location accuracy
This is how accurately a team is shooting from each location on the court – the higher the league ranking, the better the Cavaliers are at scoring in those areas.
- Around the rim – 68.2%, 11th in the league
- Mid-Range – 48%, 3rd in the league
- Short mid-range – 52.2%, 2nd in the league
- Long mid-range, 38.9%, 17th in the league
- 3-Point range – 42.1%, 1st in the league
- Non-Corner 3’s – 42.9%, 1st in the league
- Corner 3 – 40.3%, 14th in the league
Putting that into context
Everything starts with the Cavaliers shot-making on the perimeter. They’re not letting it fly for the sake of it, as highlighted by thier current standing in three-point frequency (12th in the league). Instead, Atkinson has his team hunting the best available shots, allowing them to convert at a high clip and force the defense to push up higher on the perimeter.
In terms of perimeter shot quality, here is how the Cavs are attacking coverages, courtesy of NBA Stats.
- Defender 0-2 feet away (very tight coverage)
- 2-of-3, 66.7%
- Defender 2-4 feet away (tight coverage)
- 8-of-57, 14%
- Defender 4-6 feet away (open)
- 73-of-192, 38%
- Defender 6+ feet away (wide open)
- 150-of-304, 49.3%
Similarly to the Celtics, Cleveland puts defenses in a tough spot. They lean on their off-ball movement and screening actions to generate open shots around the perimeter, with most of them coming outside of the corners.
How many times have we seen the Celtics carve open a defense with ball and player movement, like in the clip above? The Cavaliers are playing a similar brand of basketball to the Celtics.
“I don’t know if the stats support it, but I think that people are shooting more threes now,” Horford said during his postgame news conference on Sunday. “People are playing more of a style like we play, and it’s more and more teams. So, I think it’s an adjustment. For us, it’s figuring out how to win with this new style of play and how people are playing now.”
When you’re the top perimeter shooting team in the NBA in terms of percentage, defenses will always look to lock down the perimeter. Cleveland has two elite big men to lean on, as they attempt to punish any space in the middle of the floor or around the rim.
Jarrett Allen and Evan Mobley are significantly different players. However, their size and interior scoring ability give Atkinson a different dimension. As such, it makes sense that Cleveland is a top-five team for rim attempts, although I would personally expect their success rate around the cup to be slightly higher.
Given Cleveland’s style of play, and the fact they’re 27th in the NBA for mid-range attempts, I would expect the Celtics to go back to a switch 1-through-4 system with the 5-man in drop, or at least playing up-to-touch.
Or, Mazzulla could start Horford at the five and look to switch every action. The downside here is that both Mobley and Allen are adept at timing slip screens, which are the ideal way to blow up a switching coverage and create space as the defense rotates. By having someone in drop, you eliminate the risk of a slip screener having an open lane to the rim.
However, drop defense does come with its own risk…Allowing more mid-range shots or short-roll creation.
If the Cavaliers start taking more mid-range shots, Mazzulla must decide whether he’s willing to live with them. The issue is they’re a top-3 team in the NBA for shooting percentage in the middle of the floor. The most logical answer would be to let them shoot as many middies as they want, especially if it’s because they’re attacking perimeter closeouts. The math wins out in that instance, or at least it’s supposed to.
Personally, I would like to see the Celtics take a page out of the Golden State Warriors playbook and defend the Cavs in the same way that’s been causing Boston trouble. That means high pick-up points, intense ball pressure and sharp rotations as the ball enters second, third and fourth side actions. Use the drop man as somewhat of a shuttle between the baseline and free-throw line, allowing him to close down or bait space as required.
If teams want to play like the Celtics, defend them like the Celtics, too.
Defensive shot location frequency
This is where opposing teams look to generate their offense against the Cavaliers’ defense – the lower the league ranking, the more frequently teams attack those spots.
- Around the rim – 33.5%, 21st in the league
- Mid-range – 28.3%, 14th in the league
- Short mid-rage – 20.1%, 13th in the league
- Long mid-range – 8.2%, 23rd in the league
- 3-Point range – 38.2%, 12th in the league
- Non-Corner 3’s – 27.9%, 12th in the league
- Corner 3 – 10.4%, 16th in the league
Defensive shot location success rate
This is where opposing teams find success on offense – the lower the league ranking, the more successful opposing teams are from those spots.
- Around the rim – 60.7%, 4th in the league
- Mid-range – 41.1%, 8th in the league
- Short mid-rage – 42.4%, 15th in the league
- Long mid-range – 37.9%, 9th in the league
- 3-Point range – 38.6%, 28th in the league
- Non-Corner 3’s – 37.9%, 26th in the league
- Corner 3 – 40.3%, 23rd in the league
Putting that into context
eveland’s defensive approach is clear: funnel opposing teams toward the rim and lean on their two giants to make an impact. I mean, they’re a bottom-nine team in rim attempts allowed but a top-5 team in rim defense, so it makes sense. However, the Celtics’ key to success will be taking advantage of Cleveland’s inability to impact three-point shots.
Yes, the Cavs are a top-12 team for threes allowed, but they’re one of the worst defenses in the NBA for actually impacting opposing shooting, allowing 38.6% as a team.
Considering the Celtics are littered with high-level to elite perimeter threats, and the Cavs defense is designed to protect the rim, it’s clear where Boston’s advantage is going to lie. Furthermore, it just so happens that the weakest defensive aspect of the Cavaliers team is Boston’s biggest strength.
I would expect the Celtics to lean into the Cavaliers system, allowing themselves to be funneled toward the rim before spraying the ball back onto the perimeter and taking advantage of the limited point-of-attack defense within the team’s roster. Of course, this assumptions are based primarily on stats.
I haven’t seen enough of the Cavaliers this season to have an “eye test take” here…but the numbers make enough sense to believe this approach is one we will at least see the team explore.
Given the Cavaliers’ struggles in defending the perimeter, I thought it would also be interesting to look at Boston’s current three-point shot quality:
- Defender 0-2 feet away (very tight coverage)
- 1-of-3, 33.3%
- Defender 2-4 feet away (tight coverage)
- 34-of-123, 27.6%
- Defender 4-6 feet away (open)
- 114-of-300, 38%
- Defender 6+ feet away (wide open)
- 116-of-290, 40%
As you can see, the Celtics are equally adept at generating open threes and capitalizing on any space they can find. If they can consistently punish the Cavaliers’ defense, and get them into rotation with dribble-drive penetration and spray offense, Atkinson’s team could spend most of the night playing off the back foot.
Setting the Stage for the Celtics: Cook on the perimeter
The Celtics lead the NBA in three-pointers attempted and three-pointers made, per NBA Stats. As a team, they’re shooting 37% from deep. Cleveland will be facing one of its biggest tests of the season as it looks to shut down a rotation full of perimeter threats, most of whom can attack off the dribble or score across multiple levels, too.
To begin this season, Joe Mazzulla has kept his playbook pretty tight to his chest. We haven’t seen too many of the actions that became a staple for the rotation last season. However, tonight is a big game, and one would hope we start seeing some more of his Xs and Os, especially the actions that created so much success last season.
Chest
This action was arguably one of my favorite quick-hitters to generate an open three. It’s a ghost screen into a flare screen. Jaylen Brown was a regular beneficiary of this action last season and often found open threes because of it.
The following explanation of this action – and other potential actions – is from a scouting report I wrote ahead of the Cavaliers/Celtics playoff matchup last season. I think it perfectly explains why Chest works as an action and why the Cavaliers could be susceptible to it throughout the night.
This action is called “Chest.” It’s a ghost screen that flows into a flare screen. The ghost screen causes confusion with the defense’s switching principles, while the flare screen creates space as the off-ball defender chases over the screener. This action has consistently yielded good results for the Celtics when running for Brown.
Brown’s ability to shoot off the catch, drive the lane, counter the defense in the mid-range, and make reads one or two passes away make him the ideal candidate to be the focal point of this set. I chose the above clip because it shows how the action can create opportunities to cut off the flare screen and trigger a defensive rotation.
Cleveland may be willing to let teams attack the rim, but it’s doubtful they would be comfortable with Brown cutting like this clip. Once the defense rotates, you’re at an advantage. Kick the rock, move it around, find gaps, and attack.
If the defense navigates the screening sequence well, Brown can counter by coming off a re-screen and either getting into his mid-range game or attacking the rim.
If the defense looks to hedge or blitz the flare screen receiver, the screener can slip the defense and attack the space in the mid-range. And, of course, if the space is there, the screen receiver can fire away from deep off the catch.
One simple action can lead to a multitude of outcomes. That’s where the Celtics excel. They have options and answers for however, teams look to limit their offense, especially in sets like this, where there’s motion on the entry pass.
Oklahoma
Another option for the Celtics would be running some more ‘Oklahoma,’ which would use their desire to play with tempo by getting into early offensive sets.
Oklahoma is essentially a stagger screen where the first screener screens for the second screener after the ball-handler has come off the stagger. Brown is the screen receiver in the above clip, flaring off Jrue Holiday’s screen. The play is quick, it misdirects the defense as they focus on the ball-handler and the threat he poses off the dribble, allowing the screening action to occur.
Twirl
Another version of Oklahoma is known as “Twirl.” It’s essentially the same movement but with staggered down screens set on the wing. Mazzulla used “Twirl” actions a lot during his rookie season, however, it hasn’t been much of a staple since…Although it does make an appearance from time to time.
Stagger Zoom Loop
Zoom actions are ubiquitous around the NBA. Every team has multiple variations they like to run and different ways to manipulate the defense out of those actions. On Sunday, Mazzulla introduced a new wrinkle to his own Zoom offense, setting it up with a stagger screen on the strong side while having the intended hand-off receiver loop cut from the weakside low block.
The amount of motion in the action puts the defense in rotation. It tests how well the opposing team is communicating. It also opens up multiple options in terms of passing outlets, driving lanes, and potential shot locations. I would hope to see this action again tonight, especially if the Celtics want to lean into the Cavalier’s propensity to funnel offense toward the rim.
Setting the Stage for the Celtics: Point-of-attack defense
Donovan Mitchell and Darius Garland are the Cavaliers’ biggest offensive weapons. They set the table. They lead the offense. And for the most part, they’re the engine behind Atkinson’s team. As such, finding a way to limit both guards’ impact at the point of attack will play a significant role in the Celtics’ chances of success.
Last season, Brown consistently stepped up as Boston’s go-to defender against elite offensive talent. That freed up Jrue Holiday to guard bigs, nullifying any advantages when switching to guard pick-and-rolls, and Derrick White on the secondary scoring talent.
During the 2024 postseason, Brown matched up with Mitchell for a total of 8:43, holding the All-Star guard to 19 total points on 7-of-12 shooting from the field and 2-of-5 shooting from three-point range. These are not great numbers, but the statistics don’t tell us that Brown likely caused Mitchell to give up the ball on numerous occasions. Stats don’t track shots that weren’t taken.
Holiday guarded Mitchell for 18 total minutes during the postseason, holding him to 14 points on 4-of-8 shooting from the field and 2-of-3 from deep. Both Brown and Holiday are viable options to try and contain Atkinson’s biggest offensive weapon. It makes sense for Holiday to start with a cross-match, given the success he had against Mitchell last season.
Of course, the Celtics can’t sleep on Garland, either. He’s a highly talented guard and shifty ball-handler who always seems to cause the Celtics issues. As such, I would like to see the Celtics go back to some of their pack line principles, at least in terms of gap and nail help, as that often limited opposing teams’ success when looking to penetrate off the dribble and attack the paint.
Finding ways to limit — or at least contain — Mitchell and Garland will be key to the Celtics’ chance of success…Of course…They must also…
Setting the Stage for the Celtics: Protecting the rim
…Protect the rim against Allen’s rim-running and Mobley’s size in the dunker spot.
The Celtics are doing an admirable job of keeping opposing teams shots outside of the paint. They currently rank 16th in the NBA for defensive rim frequency, allowing 32% of opposing offense within four feet of the basket. Part of that is due to the size of Luke Kornet and Neemias Queta, with both being reliable shot deterrents.
The problem is that the Celtics also have one of the worst rim defenses in the league, ranking 20th in the percentage of shots scored within four feet of the bucket with 67.8%.
As such, Cleveland will undoubtedly feel like they hold an advantage in terms of interior scoring. Boston’s (kind of) struggles on the defensive glass — they’re 15th in defensive rebound percentage, securing 70.7% — will likely give the Cavaliers the green light to crash the boards and fight for second-chance scoring opportunities.
It will be interesting to see whether Mazzulla runs with a double-big lineup or looks to lean on other tactics such as cross-matching, veer-backs, and potentially a weakside roamer.
Whatever he chooses, there will be a battle on the Celtics defensive glass, and it will likely play a significant role in Boston’s chances of ending the Cavaliers’ undefeated start to the season.
Wrapping it up
Coming into this season, I didn’t have Cleveland among my primary threats to the Celtics’ chances of retaining their championship, or at least their spot as the top seed in the East. However, the Philadelphia 76ers are struggling right now (2-11, woof) and the Milwaukee Bucks have been an enigma.
Suddenly, we’re talking about a mid-November NBA Cup game against the Cavaliers as the first big contest of the season. Atkinson has already made a difference for his new team, and they’re playing like a genuine contender. Things won’t be easy for the Celtics on either side of the floor.
However, if Boston can take advantage on the perimeter, limit Cleveland’s impact on the glass and in the paint, and stick to their game plan, regardless of how they start the game, they will have a chance of sending a message. We know what this Celtics team is capable of when they’re locked in and motivated. I for one, am hoping to see Boston treat Cleveland the same way they treated the New York Knicks to begin the season.
CelticsBlog graciously allowed this article to be cross-posted from my “Celtics Chronicle” newsletter.