The Celtics have two All-Stars, sit third in the East with a 38-16 record, and boast the league’s third-best net rating at +6.8. However, ostensibly, this team is an unambiguous contender. The Celtics’ regular season success stems from a source different from that of a traditional contender.

Where the Milwaukee Bucks have Giannis Antetokounmpo, the Los Angeles Lakers LeBron James and Anthony Davis, and the Los Angeles Clippers Kawhi Leonard and Paul George, the Celtics are lacking for one of those unimpeachable MVP candidates.

Instead, the Celtics supplement five core perimeter talents with a host of valuable complementary players. And in the regular season, they chug along, walloping bad teams and competing with the best.

The team’s two stars, Jayson Tatum and Kemba Walker, are great players, comfortably deserving All-Stars, but inarguably a tier or two below the league’s absolute best. While reliance on second-tier stars has proven a viable formula for regular season winning, some recent struggles by those two could presage postseason shortcomings relative to the expectations of a true contender.

Though the Celtics emerged from their February 9th matinee with the Oklahoma City Thunder victorious, the game offered more concerning data points for an emerging trend:

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In the first half, the Celtics stuck to their bread and butter with a high dose of Walker playing on the ball in pick-and-roll. Walker is among the league’s premier pick-and-roll handlers, sporting obscene volume and 96th percentile efficiency per Synergy, but qualitative qualms present themselves against certain defenses.

When an imposing interior deterrent shares the floor with Walker, he simply lacks the size and length to finish like larger star guards. Concerning is how this deficiency applies to some of Boston’s stiffest competition in the East:

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Particularly against Philly’s supersized front court with Al Horford and Joel Embiid (but to a degree against Antetokounmpo and Brook Lopez of Milwaukee), Walker has struggled immensely to finish:

The implications of Walker’s finishing woes ripple well beyond his own scoring, as he no longer presents a viable threat to the defense as a penetrator and consequently cannot force the rotations and compromises that facilitate team offense.

Against Oklahoma City, Walker’s first half impotence on the ball left the Celtics with a 9-point deficit at the break; Walker had 13 points on measly 3-for-11 shooting.

Of course, the Celtics managed an improbable comeback Sunday in Oklahoma City, and Walker finished with a very respectable stat line, but they did so by moving away from their star point guard:

11 points in 2+ minutes for Jayson Tatum, who took over to start the 3rd quarter pic.twitter.com/OVKFUmbhty — Jackson Frank (@jackfrank_jjf) February 9, 2020

As they have in recent weeks, the Celtics played through Tatum. That meant pick-and-roll reps making use of the strategy I detailed here, Tatum using length and size as a ball-handler to shield himself and finish against the very deterrents who were thwarting Walker, and deceptive and intelligent off-ball movement to self-create without even touching the ball.

And thanks to Walker’s elite shooting and accompanying gravity, the Celtics still derived value from their diminutive point guard:

Watching 2nd half now: feels like Celtics use Kemba best when they use him for "dynamic spacing" rather than just having him put his head down and drive.



Here he frees Tatum with his gravity: Schroder can't dig on initial drive or sink into the lane. pic.twitter.com/bZcCWUEDXt — Basile Genève (@basile_legrand) February 10, 2020

Though the Celtics built out a large enough lead with Tatum shouldering the load, Tatum’s flaws nearly prompted a miraculous OKC comeback when they figured out how to attack him as well:

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In the game’s final minute, the Thunder sent two defenders to deny Walker in the back court, funneling the ball into Tatum’s hands. With Tatum thrust into the initiator role, wily Chris Paul preyed on Tatum’s loose handle, poking the ball away for a pair of near game-swinging turnovers.

The disruption of Tatum’s handle late against OKC was merely a prelude to the hell Tatum endured against the Houston Rockets.

It is essential to understand how Jayson Tatum has emerged as a bona fide star this season to grasp why the Rockets were such a nightmare for him:

The secondary move from Tatum hitting Bamba with the in and out after he comes off the screen is great PnR ball-handler craft pic.twitter.com/bS1DtaaeG8 — Max Carlin (@maxacarlin) February 6, 2020

Jayson Tatum has the pull-up out of PnR working pic.twitter.com/S7tGnvTfWs — Max Carlin (@maxacarlin) January 21, 2020

Tatum has become one of the premier ball screen players in the league, posting 86th percentile efficiency on considerable volume of pick-and-roll possessions, per Synergy. He’s done so on the strength of elite pull-up shooting and a handle that is quite advanced for a wing/forward despite its looseness.

It sounds counterintuitive to suggest both that Tatum’s loose handle is a problem and one of the keys to his success as a pick-and-roll handler, but that is the case. Tatum’s handle is loose, but given some space by a ball screen, he possesses controlled and deceptive moves to create space against bigs attempting to contain him, as he does in the above clip against Mo Bamba.

The Rockets’s switch-everything scheme eliminates these advantage situations in which Tatum has space to execute moves against retreating bigs. Instead, it concedes Tatum switches:

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Like we saw with Paul, it’s somewhat unexpectedly smalls who give Tatum the most trouble on the ball. As Austin Rivers pressures Tatum’s handle, he cannot generate an angle to get downhill or space for a pull-up, and he resorts to an impossible turnaround. Tatum also struggled with switches against more like-sized defenders:

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Tatum has grown into one of the league’s premier pull-up 3-point shooters, but even for a marksmen of his caliber, a sidestep 3 contested tightly by Robert Covington is not a particularly high value shot. Nonetheless, that is all Tatum can generate on the ball against a radical switch-everything defense, which baits him into his worst tendencies. And while there’s no clear analog to the Rockets in the East, a switch-heavy look is something the Celtics must be prepared for against the Bucks or Toronto Raptors come the postseason.

Unlike against Oklahoma City, the Celtics lacked another star to turn to against Houston, as Walker had similar struggles to create anything but difficult pull-ups in isolation.

Some may look to Jaylen Brown’s line in the box score vs. Houston as evidence that the Celtics do have another creation option, but applying the slightest context to those numbers disqualifies that notion. Brown posted 19 points on 7-for-12 shooting, but just 2 of those points cam on self-created looks in the half court, the remaining 17 coming via transition or spot-ups in the half court. When Brown did attempt to create in the half court, the results were disastrous:

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Definitely need Jaylen Brown self-creation possessions when Kemba, Tatum, and Hayward are available pic.twitter.com/VYsTwkXTiB — Max Carlin (@maxacarlin) February 12, 2020

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There seems to be more legitimacy to the idea of Hayward’s versatile creation style thriving regardless of defense, but the fact of the matter is that the team’s offense has been dreadful with Hayward attempting to lead units sans Tatum and Walker to the tune of a 106.2 offensive rating.

Hayward’s difficult shot-making and exquisite decision-making are a formidable combination, but his lack of rim pressure, evident in 30% rim attempt frequency and 18.2% free throw rate present the same issues for driving team offense as does Walker’s ineffectiveness against stout interior defenders.

To be successful against every defensive coverage thrown at them, the Celtics will likely need to rely upon the very thing that’s elevated them to ostensible contender status: teamwork.

One of the Celtics's best offensive possessions of the game. Hayward gets some penetration, quickly moves the ball to Wanamaker to attack a defense in rotation, Grant seals pic.twitter.com/TSr2aW8LXJ — Max Carlin (@maxacarlin) February 12, 2020

By getting multiple ballhandlers attacking in concert, playing intelligently and quickly, and executing well-designed offense, the Celtics do have a collection of talent that can score together.

Of course, depending on such team concepts in the absence of a true superstar leaves very little margin for error. Attacks must be crisp, decisions instantaneous, and the scheme that’s being executed flawlessly conceived.

Whether the Celtics can thread that needle remains up in the air, and likely will until the later rounds of the playoffs, but evidence from recent games surely offers some cause for concern.