Making Sense of the Current Boston Celtics Roster
The Boston Celtics have no shortage of young players and draft picks. But what does that mean? Is a major trade looming for Boston? The rumor mill has been relatively silent, so in the meantime, let's try to make sense of what Brad Stevens is looking to do with this roster.
The Incumbent Guards
The Celtics had 10 separate players start at least 10 games last season. Of the 10, three are no longer with Boston (Rajon Rondo, Brandon Bass, and Jeff Green). After Rondo was traded to the Mavs, Marcus Smart became the starting point guard -- Smart put up 7.8 points, 3.3 rebounds, and 3.1 assists a season ago. Far from the most efficient player, he shot 37% and posted a nERD of -1.5.
Smart’s had a back-and-forth NBA Summer League. In the two games he played in Utah, he led the league in points and assists and shot a solid 44%. In the three games he played in Las Vegas, Smart averaged 10.7 points per game while shooting 26.5%.
Despite his efficiency troubles, Smart has shown he can make an impact on the defensive end. After all, his Defensive Rating was second best on the Celtics last year according to NBA.com.
The other incumbent starter is Avery Bradley, who started all 77 games he played in last year. Since getting drafted five years ago, the Texas product has made a name for himself as one of the very best defensive guards in the league, garnering an All-Defense award in 2012-13. Yet, it’s hard to see his impact looking at the stats -- last season, he averaged just over a steal per game while accumulating all of 15 blocks the entire year.
The advanced numbers tell a similar story. Per NBA.com, he ranked just behind Smart for third on the team in Defensive Rating. According to basketball-reference, he posted 2.1 Defensive Win Shares also similar to Smart.
Offensively, Bradley is decidedly below average. He averaged 13.9 points off of 43% shooting. Amongst qualified Celtics, he had the second worst Offensive Rating last season.
But Bradley performs much better with Smart on the floor. With both of them in the game, Bradley averaged 1.15 points per possession. With Smart on the bench, that number dropped to 0.99. Bradley shoots almost a full seven percentage points better with his fellow backcourtmate playing with him.
The Celtics' most important player may be a player who didn’t start a single game for them last season. After trading for Isaiah Thomas, the Celtics went 20-11, which translates to 53 wins across 82 games. With Boston, Thomas averaged 19 points and 5.4 assists. With a 44.8 eFG% on pull up shots, he’s proved himself as one of the best pull up shooters in the league. He’s also shown he can be one of the best drivers in the league, ranking seventh in points per 48 on drives.
But as has been his weakness since he came into the league, Thomas has struggled at defense -- among qualified players, he ranked in the bottom 20 in Defensive Plus-Minus.
While Smart makes Bradley better, the opposite is true for Thomas. With Smart on the floor, Thomas averaged .07 fewer points per possession and has an Effective Field Goal Percentage nine percentage points worse.
So with whom in the backcourt does Thomas play better? He has almost identical stats with or without Bradley. Evan Turner played about 40% of the Celtics possessions at guard, and with Turner, Thomas had 1.16 points per possession. When Turner went to the bench, Thomas averaged 1.05 points per possession.
A starting backcourt of Smart and Bradley makes for one of the better defensive backcourts on the league, not to mention when playing together, they play better offensively. With Thomas coming off the bench, he could provide quick offense that the combo of Smart and Bradley won't be able to.
This offseason, the Celtics drafted Terry Rozier and R.J. Hunter. Both Rozier and Hunter had strong performances in the Summer League, with both averaging around 12 points per game. Rozier, a point guard out of Louisville, was fourth in the ACC in points and first in steals. Hunter was a sharp shooter at Georgia State who averaged over 17 points per game all three of his years as a Panther.
Rozier and Hunter -- along with James Young -- will provide points off the bench to support a defensive-minded starting backcourt. They also may bring some much-needed energy to the transition game, which Boston ranked last in the NBA for last year. The Celtics also added Zoran Dragic, but it seems likely that he will be on his way out of Boston.
In addition to playing shooting guard, Turner also sets up at small forward. He's a do-it-all kind of forward who averaged 9.5 points, 5.1 rebounds, and 5.5 assists last season. He played in every game and started 57 of them. However, he shot just 43% and posted and Offensive Rating of 96.
Turner's main competition for the starting role is Jae Crowder, who came over from Dallas in the Rondo trade. Crowder, like Turner, struggles from efficiency woes too. He connected on less than 30% of his threes last year, and 42% of his overall shots. He's got the advantage over Turner in rebounding, but a closer look at the numbers reveals it's not as different as one may think. Both Crowder and Turner averaged around 9.5 rebounds per 100 possessions, and they both collect approximately 10% of all rebounds while on the floor.
So who should start? The answer seems easy when looking at nERD. Turner had a nERD of -4.6, while Crowder was at 1.3. It would make sense for Brad Stevens to start Crowder and take advantage of Turner's versatility off the bench.
In his second season with Boston, Tyler Zeller posted averages of 10.2 points and 5.7 rebounds. He shot an impressive 55% from the field and had the highest nERD on the team.
Zeller plays best on pick and roll. According to NBA.com, 24% of the plays that Zeller was involved were pick and roll. He was in the top 10% of all qualified players in pick-and-roll points per possession scoring. Only two players who ran pick and roll more often than Zeller did it as efficiently as he did.
Backing up Zeller will likely be Kelly Olynyk. Despite Olynyk's status as a reserve, he has proved he can play meaningful minutes. Olynyk started the first 13 games of the season, scoring over 15 points five times and posting two double doubles.
Last year's main starter at power forward was Jared Sullinger. This was the first year that the third year man out of Ohio State played a majority of his time at forward. Sullinger averaged 13.3 points but did it off of 44% shooting.
His main problem seems to be his inability to get to the rim, as only 27% of his shots taken last year were within three feet of the basket. For comparison, Zeller had about 46% of his shots from within that distance. Since Sullinger can't get to the basket, he's forced to pretend to be a stretch four and take outside shots, which he's shown he's good but not great at. He connected on just 28% of his three-point attempts, however, he made 45% of all two pointers further than 16 feet.
So what does that mean? Like Tim Duncan or Kevin Garnett, Sullinger can knock down mid-range twos, but when he steps a few feet back, he can't make threes. And yet he still took the third most threes on the team. If Sullinger cuts back on his three point attempts, he could become a solid stretch four.
While Sullinger's the incumbent starter, Boston added several frontcourt players during the offseason, including David Lee and Amir Johnson -- both of whom will be in the running for the starting power forward spot. Both players had better nERD ratings than Sullinger last season, mainly because they are more efficient scorers. Both averaged per 36 scoring numbers that were comparable to Sullinger. Yet, Johnson and Lee both shot over 50%.
Going by nERD, Lee should be the starter going into next season. With Johnson and Sullinger getting minutes off the bench. Also complicating the bench are Perry Jones III and Jonas Jerebko. Jones III showed he could be a versatile scorer when he dropped 32 in his second game as a starter. Jerebko has consistently been a sharp shooting big man, knocking down 41% of his three last season. Both players provide even more depth for this young Celtics team.
All told, the Celtics have 17 players with guaranteed contracts for next season. It seems likely that Danny Ainge will be making a move to deal several of his young players for a more established player. So, are the Celtics one player away from championship contention? Probably not. But in the anemic East, one player could mean the difference between a borderline playoff team and a contender for the Eastern Conference Finals.