Why are the Celtics bad? Because they’re bad!
All Stats from Cleaning the Glass / Basketball Reference, and updated as of February 26.
For the past five years, the Celtics have taken on a variety of identities: scrappy underdogs (2015/2016), up-and-coming over-achievers (2016/2017), flat-earthers (2017/2018), young and talented contenders (2018/2019 and 2019/2020). But in 2020, the Celtics seem to have taken on a new identity.
At first glance, this felt like the year everything was going to fall into place — after replacing locker-room cancer Kyrie Irving with just happy-to-be-out-of-Charlotte Kemba Walker, and clearing out usage and minutes for ascendant stars Jayson Tatum and Jaylen Brown, the Celtics finally had the perfect balance of shot creators, playmakers and role players.
Obviously for the 15–17 Celtics, this season has been anything but perfect. The underperformance of Kemba Walker can’t be understated, as well as Marcus Smart being out 3–4 months. With Kemba playing near an all-star level and Smart adding a fourth competent playmaker to pair with Tatum and Brown, this season likely looks and feels much different.
However, the Celtics still have two Under-25 All-Stars. They’re one of three teams in the East with multiple All-Stars and the other two teams, Brooklyn and Philadelphia, are first and second in the East Standings. And yet, the Celtics are under the…Pacers? And the Raptors? And the…*gulp* …Hornets?
What could possibly be going on? Oh right, the Celtics are trotting out a team of two All-Stars and then hot, hot garbage! While the NBA is increasingly becoming a star-driven league where 100 James Harden step-backs can turn a team into a four-seed in the West, Tatum and Brown aren’t Harden, which means the rest of the Celtics roster needs to do more than get-out-the-way. Unfortunately, that seems all this roster is equipped to do — the best way to explore the depths of how low this Celtics supporting cast can sink is to line ’em up in a game I like to call: “Are you better than a Charlotte Hornet?!”
The way the game works is we compare, by ranked usage, the players on the Celtics, with the players on some other Eastern Conference teams — at the bare minimum, we must hope that our Celtics are better than their Hornet counterparts. But only the data will tell!
The main stat I will be looking at is True Shooting Added from Basketball Reference, which simply accounts for points added on true shot attempts (including attempts where a player is fouled and accounting for threes versus twos) above league average. This is a useful heuristic for letting you know if you would rather have your beloved Celtic/Hornet/Bull taking a shot, or some league-average schmo.
I also show net rating here, which is the difference in points per 100 possessions scored and points per 100 possessions allowed when the player is on the floor — I include this as a secondary metric, as a lot of these players’ net ratings will be contingent on the lineups they play with.
This doesn’t account for playmaking or defensive impact, and also will be impacted by the types of shots each player is taking. However, comparing players with similar “roles” by going by ranked usage should account for some of that noise.
A few things stand out when comparing players against five nearly .500 Eastern Conference teams — one is that Kemba and Aaron Holiday are both not having good years. Holiday has been thrust into a role above his talent-level due to the Pacers trading away Victor Oladipo and acquiring an injured Caris LaVert — however, this is exactly the type of poor shooting we’d expect to see from a player who is being overextended into a high usage role.
Holiday’s horrible numbers are Kemba’s saving grace, as the other three comparisons are all having great shooting years, albeit with lower usage numbers, indicating that Kemba may be shouldering a tougher load than his peers.
Why, you might ask, is Kemba using so many possessions when he’s not shooting that well? He should just give the ball up! To…oh no, is that Jeff Teague’s music?
Ah, my eyes! Once again, a Celtic is saved by having one other player having a worse shooting season, as Devonte’ Graham has fallen off this year, shooting only 34% from three on 8 attempts per game. Graham though, is at least attempting to space the floor; Teague on the other hand takes less than 2 threes per game, and it’s not because he makes his hay in the paint: from inside the arc he is shooting an absolutely abysmal 30%.
The other three players are all good — doesn’t seem fair.
Rounding out the top 5, Payton Pritchard is…still not above our league average mark, but certainly not plumbing the depths of failure like his teammates. This exercise has mostly made me just feel bad for the Pacers — McConnell does not compare as favorably to his fellow diminutive point guard, and that’s mostly driven by the fact that McConnell is simply not a shooter. Pritchard can actually hit an open three, which makes the difference here.
However, Porter and Monk provide some real offensive juice at these spots — both are not only shooting 40%+ from three on over five attempts per game, but can also make a move off the dribble and finish in traffic or through contact.
What is glaring about the fourth and fifth spots is just how much scoring punch the Celtics lack after their top three— Pritchard and Teague are each averaging under seven points per game, and not even doing so on particularly efficient shooting. This is a glaring difference from a team like the Bulls, who after LaVine, still have three to four players who can get buckets at an NBA-level (although to be fair their second highest usage player is Coby White who is, how does one say, not good).
This problem is summed up for the Celtics in their Net Rating numbers:
This is the crux of the Celtics issue — most teams built around two stars benefit from the ability to play one or the other throughout the game (and both in crunch time) and maintain their Net Rating. For the Celtics, their supporting cast simply isn’t good enough for a second-tier All-Star to carry them, even when comparing against a handful of teams the Celtics *should* be better than.
If Kemba can return to form and provide the Celtics a legitimate third option, and Marcus Smart can come back and do Marcus Smart things, things will look much different a few months down the road, but until then, the Celtics will continue to project their newest identity: bad.