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Analyzing the Boston Celtics' frontcourt pairings and potential changes to come

Brad Stevens has hinted at potential lineup changes; what should we expect?

"I choose you!"
"I choose you!"
Mike Lawrie/Getty Images

Get ready for some changes to the Boston Celtics' rotation, as coach Brad Stevens has started to experiment with a number of different frontcourt combinations in an attempt to find the best possible pairings.

"Anytime you have a 3-6 team, you're searching for consistency all over the place," Stevens said before Wednesday's 101-90 victory versus the Philadelphia 76ers, hinting at potential revisions. "I think all of the guys have had their moments where they've played exceptionally well, but as a group we're still searching for our most consistent groups together."

After Stevens benched Kelly Olynyk in the second half of Monday's game and then rode the red-hot Brandon Bass on Wednesday night, it has become clear that he is searching for what works best. The formula might change night-to-night, but finding continuity is important.

This article will look to answer how each frontcourt combination has performed through 10 games this season, as well as how the rotation could look at the start of games going forward.

What to know: The primary statistics used in this study are called "offensive rating" and "defensive rating," which is the number of points per 100 possessions a team scores or allows. All stats used have extremely small sample sizes because the Celtics have only played 10 games this season, but we can't let that stop us from doing research, because NBA teams certainly aren't. Most statistics used are from NBA.com, though pairings featuring Green are from NBAWowy.

Looking at the big picture

The Celtics rank eighth in the league in offensive rating (106.8), but 24th in defensive rating (107.2). To put it simply, their offense has been statistically "good" and their defense has been statistically "bad."

As any fan knows, the Celtics have looked amazing for some stretches of games and terrible during other ones. As Stevens alluded to before Wednesday's game, he must try and maximize on the positives.

So, who is performing and who isn't? Here are the offensive and defensive ratings for each of Boston's rotational big men, including Jeff Green, though he plays the majority of his minutes at small forward:

Player On Court Rating Off Court Rating Difference
Sullinger Offense 110.5 100.5 10
Sullinger Defense 105.4 110.3 -4.9
Olynyk Offense 107.2 106.4 0.8
Olynyk Defense 109.6 104.4 5.2
Zeller Offense 104.8 107.7 -2.9
Zeller Defense 105.5 107.9 -2.4
Bass Offense 100 111 -11
Bass Defense 104.9 108.7 -3.8
Green Offense 106.8 106.9 -0.1
Green Defense 108.4 104 4.4

Good things have happened so far this season with Jared Sullinger on the floor, as the team is 10 points per 100 possessions better offensively and 4.9 better defensively. Sullinger's ability to score in a number of ways, as well as his passing skills, clearly shows in the numbers.

The differences between Kelly Olynyk, Tyler Zeller, and Jeff Green's on-off splits are extremely minor. However, the team has clearly been better defensively with Olynyk on the bench, as they allow 5.2 points less per 100 possessions.

The only other major difference that pops out is Brandon Bass' offensive rating. Despite his 23-point performance against Philadelphia, the team still scores 11 points more per 100 possessions with him on the bench. This may speak to the tendency for the ball to "stick" in Bass' hands, especially compared to his pass-savvy teammates.

But what does this data tell us? Not a whole lot, actually. That was only an introduction to ease you into the meat of the study, the frontcourt pairings.

Front Court Pairing (Minutes) Team OffRtg Team DefRtg Net Rating
Sullinger & Olynyk (152) 110 108.8 1.2
Sullinger & Bass (75) 109.3 104.1 5.2
Olynyk & Bass (62) 101.2 110.7 -9.5
Sullinger & Zeller (44) 112.1 89.4 22.7
Zeller & Bass (42) 82 98.6 -16.6
Sullinger & Green (31) 112.9 124.2 -11.3
Olynyk & Zeller (30) 112.4 119.1 -6.7
Zeller & Green (20) 130 132.5 -2.5
Olynyk & Green (17) 97.1 111.4 -14.3
Bass & Green (1) 40 80 -40

The above chart details Boston's top 10 frontcourt pairings, sorted by minutes played. Here's how to read the data: in column one, the on-court combination is listed. For example, Jared Sullinger and Kelly Olynyk have played 152 minutes together, and during that time the Celtics have a team offensive rating of 110 and a team defensive rating of 108.8. This works out to be a positive net rating of 1.2.

Frontcourt pairs discussion

The Sullinger and Olynyk pairing has been effective this year, with a net rating of 1.2. They're scoring a lot of points, but allowing quite a bit too. If Brad Stevens is looking for better balance, one pairing sticks out like a sore thumb.

That pairing is of course Sullinger and Zeller, with a ridiculous +22.7 net rating. The Celtics have an incredible 89.4 defensive rating with that frontcourt unit, and while that number will certainly not sustain over the course of the season, it does suggest that something is positive there with that combination. The fact is, even without Olynyk's three-point shooting, the team is still able to space to floor due to Zeller's fantastic passing ability.

Yet, that combination has only played 44 minutes together, the fourth-most common pairing, compared to the 75 minutes that Sullinger and Bass have played together. And while spacing could be a potential issue with Sullinger and Zeller, it almost certainly is with Sullinger and Bass, since Bass is not a three-point threat, and is a substandard passer to Zeller.

Interestingly, and somewhat surprisingly, the team has not played well with Jeff Green at power forward. Though we're working with small sample sizes, the team's net ratings when Green is paired with either Sullinger or Olynyk are not promising.

Here are the frontcourt groupings with Jeff Green always on the floor at small forward:

Front Court Grouping (Minutes) Team OffRtg Team DefRtg Net Rating
Sullinger, Olynyk, & Green (130) 111.6 108.5 3.1
Sullinger, Bass, & Green (42) 103.2 95.7 7.5
Olynyk, Bass, & Green (39) 99.5 107.4 -7.9
Olynyk, Zeller, & Green (26) 107 137.1 -30.1
Zeller, Bass, & Green (26) 79.8 104.7 -24.9
Sullinger, Zeller, & Green (22) 114.8 90 24.8

This data reinforces the pairings previously shown. Again, lineups with Sullinger have a positive net rating regardless of the combination, and everything else is negative.

Once again, the most effective frontcourt this season has been the one featuring Sullinger and Zeller, but they are the least-used combination from the group. With a +24.8 net rating, they are exceling on both ends of the floor. It might be beneficial for Stevens to begin experimenting with this lineup more frequently.

What could the rotation be?

This article isn't being written to try and answer "closes games," because that can situationally change on a night-to-night basis, but it's meant to help shine a light on which groups of players give the Celtics the best chance to build and sustain a lead.

One thing is for sure: Jared Sullinger needs to start. No matter which player he's with, Sullinger makes things work. He's versatile on both ends of the floor and when he's not on cruise control, he plays at a borderline All-Star level.

But should Kelly Olynyk or Tyler Zeller start alongside Sullinger? There is no clear-cut answer, but I would lean towards Zeller for his defensive impact. The Celtics are just flat-out better defensively with him, and poor defense has been a huge cause of their struggles.

Olynyk is obviously an all-around superior offensive player, but he can make that same impact by being the first big man off the bench. Playing alongside the likes of Evan Turner could possibly allow Olynyk to be even more of a focal point, as opposed to sharing the load with the starters.

If Brad Stevens' two frontcourt pairings during the start of each game were generally Sullinger and Zeller, and then Sullinger and Olynyk, he'd always make use of his two best combinations. At the end of the first quarter, Bass could substitute in for Sullinger, giving him a breather.

At the least, I want to see Stevens use the defensive-oriented Sullinger and Zeller frontcourt more often. The Celtics must improve on their 28th-ranked defense, because the offense seems to click no matter which frontcourt combination is on the floor. Finding chemistry with Rajon Rondo shouldn't be a concern, either, because everyone plays more efficiently with the captain on the floor.

Defense can create offense, anyway. When Sullinger and Olynyk are on the floor, the Celtics score 22.6 percent of their points off of turnovers, the most of all frontcourt combinations. The average for the team is just 15.5 percent, which ranks 18th in the league.

Playing hard-nosed defense might actually be the reason why the offense hasn't taken much of a hit with Olynyk on the bench. Even though he's had a very strong season, Zeller might bring more consistency on both ends, ultimately helping the team overall.

I fully expect Brad Stevens to tinker with the rotation as we plow through the month of November. Stevens is a master of game-to-game adjustments, and his recent quotes to the media suggest that gears are turning in his head, and he's looking to make a change. With a 4-6 record, he might have to make one sooner rather than later.

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