Things are going well in Boston. The Celtics are 41-17 after going 3-1 on a West Coast swing where Jayson Tatum continued to take a giant leap forward into the NBA’s top tier. But, like many other instances this season, Boston still was shorthanded.
Kemba Walker missed the entirety of the road trip with a sore left knee, an ailment that’s plagued him off and on for over a month now. The Celtics are fortunate their quality depth has stepped up. Tatum, Jaylen Brown, Marcus Smart, and Daniel Theis all were huge in Boston’s three post-break wins, but at some point, it’d be nice for Brad Stevens to be able to trot out his best starting five, right?
Out of 58 games thus far, the Celtics have started Walker, Tatum, Brown, Theis and Gordon Hayward just 17 times. That’s 41 games without a member of the starting five. Most teams would struggle to stay above water with consistent injury problems, but, again, Boston has held strong. While missing a starter, the Celtics have gone 31-10. The most common lineup came after Hayward suffered a fractured hand against the San Antonio Spurs on Nov. 9. Over his month-long absence, Smart routinely filled in, resulting in a starting five of Walker, Tatum, Brown, Theis and Smart on 10 occasions (6-4), the second-most of any combination this season.
So if Boston has been able to stay afloat amid injuries, how good will they be when fully healthy? The addition of Robert Williams off the bench will be huge for the Celtics’ depth, but for now, let’s look at the starting five’s numbers during their healthy games together.
In 17 games, the combination of Walker, Tatum, Brown, Hayward and Theis has played an average of 11.1 minutes together, posting a 52.3 percent shooting clip with a solid net rating of 12.8. The latter value is carried by an impressive offensive rating of 121.1.
How do these numbers compare to the league’s best? First, some reasoning as to why it’s important to make these comparisons, even when Boston’s sample size is a bit smaller than other lineups across the league. The Celtics ideally will run out their healthy starting five when the postseason comes around. Of course, with the postseason comes better opponents, so putting Boston’s five next to the NBA’s best units can give us a bit of an idea where the Celtics stand from a statistical standpoint.
To make this comparison, I looked at five-player lineups across the league that have played a minimum of 15 games together. Out of those combinations, I took lineups that played six or more minutes together on average, eliminating crossover lineups that only see brief stints on the floor together. Of course, the Celtics find themselves toward the bottom of these metrics in terms of data size at 17 games and an average of 11.1 minutes, but that’s what injuries do. The majority of teams have multiple lineups that fall under these filters. The Celtics have just one — their original starting five.
The best net rating in the group? The Dallas Mavericks’ lineup of Tim Hardaway Jr., Dwight Powell, Dorian Finney-Smith, Maxi Kleber and Luka Doncic. This combination has a net rating of 34.8 in 6.1 minutes over 16 games — a very small sample size among our set of lineups. It’s not necessarily a fluke, though. Dallas has boasted one of the league’s best offensive units this season, and that’s evident here with an offensive rating of 128.3. Unfortunately, Dwight Powell’s torn Achilles prematurely ended this lineup’s season. So due to the small sample size and an inability to play together, we’ll push this group to the side.
Looking at lineups with bigger minute totals is what really separates the elite teams from the bunch. Among the top? The Oklahoma City Thunder, Milwaukee Bucks, Philadelphia 76ers, Utah Jazz, Los Angeles Lakers and Toronto Raptors.
OKC’s combination of Chris Paul, Danilo Gallinari, Dennis Schroder, Steven Adams and Shai Gilgeous-Alexander has played in 38 games together. Schroder has started just one of his 57 games, but he closes more often than not, which is more crucial than being on the floor for the opening tip. This group has a net rating of 30.5. Yes, that makes Boston’s 12.8 rating look rather mediocre. However, the previously-mentioned Dallas lineup is the only other combination with a net rating north of 30, so this OKC combination makes everyone look pretty minuscule from an advanced numbers standpoint.
It’s not surprising that Milwaukee’s starting lineup has a net rating of 19.3 in 34 games together (roughly 11 minutes per night). Giannis Antetokounmpo, Khris Middleton, Eric Bledsoe, Brook Lopez and Wes Matthews make their mark defensively, allowing just 90 points per 100 possessions. In comparison, the Celtics starting five allows 108.3.
Philadelphia has two separate units allowing 91.4 and 97.1 points per 100 possessions, coming in as the second and sixth-best defensive ratings, respectively. Both are over 10 points better than the defensive rating of Boston’s starters. Much of that is thanks to the Sixers’ size, something the Celtics don’t have a whole lot of. The tallest players in Boston’s starting five are 6-foot-8 (Theis and Tatum), but they make up for a lack of size with switch-heavy schemes and versatility along the perimeter.
These comparisons do not discount what Boston has done defensively this season. Remember — we’re looking at one lineup. One combination of five players that’s played in just 17 of 58 total games this season. As a whole, the Celtics have been very good defensively. As of Feb. 27, they have the third-best team defensive rating in the NBA at 105.9, trailing only the Bucks and Raptors.
Now onto Los Angeles. Boston’s starting lineup is right next to the Lakers’ top unit. LeBron James, Anthony Davis, JaVale McGee, Danny Green and Avery Bradley have a net rating of 13.4 in 29 games this season, just 0.6 better than Boston’s starting five. Offensively, the Celtics have been more efficient than Los Angeles, but again, it’s tough to get a true value due to Boston’s smaller sample size.
Boston’s starting five comes in at 14th in net rating for lineups with a 15-game, six-minute minimum. Their offensive rating is sixth at 121.1, and a lot of that is thanks to ball movement — the group has the 12th-best assist ratio at 20.9. It’ll be interesting to see what happens to the starting unit’s defensive rating with more time on the floor, especially considering their versatility at spots two through five. That’s something most teams don’t have, and Stevens’s switch-heavy actions on defense benefit immensely from that ability.
From a traditional stats standpoint, Boston’s shooting ranks among the top of our data set. Their efficient 52.3 percent shooting percentage is the third-best, trailing only the previously-mentioned Dallas lineup and the Lakers’ secondary unit. The Celtics’ starters also boast a 44.6 percent clip from deep, which is second only to Dallas.
One way or another, the Celtics have now beaten each of the league’s top 12 teams (other than the Houston Rockets) at least once. They’ll have their second and final regular-season chance to take down Houston on Saturday at TD Garden. Advanced statistics or not, the Celtics are among the league’s best. Time will tell how Boston’s starting five handles that crowd once they find consistent health.