Despite having lost nine of their last 11 games against the Boston Celtics over the past two seasons, the Philadelphia 76ers had every reason to feel good about their chances on Tuesday night.
The Sixers had just upgraded their roster with sharpshooting forward Tobias Harris, who'd helped the team rack up a 124.4 offensive rating in two games since the deadline-week trade. They were playing at home, where they were 23-6 on the season. And they were hosting a Celtics team that was coming off two deflating losses, wanting for joy, and missing its best player. But for all the changes and extenuating circumstances that ought to have swung things in Philadelphia's favor, the outcome proved familiar. The Kyrie Irving-less Celtics remained a puzzle the Sixers can't solve and came away with a 112-109 win.
Plenty of factors contributed to the result, and while some of them were outliers - like Harris missing all six of his mostly clean looks from 3-point range, and Gordon Hayward hitting six of the seven he attempted - more of them were recognizable continuations of existing patterns.
The most obvious and most essential of those patterns was the way the matchup between Joel Embiid and Al Horford played out. Horford was Embiid's kryptonite once again in this one, managing to stone the hulking Sixers center in the post at one end of the floor and to burn him with a bevy of pick-and-pop threes at the other. Embiid, who blamed the officiating for letting Horford's defensive physicality go unpunished, still went for 23 points and 14 rebounds. But Horford dropped 23 of his own, and did so on seven fewer shooting possessions. He was immovable on the block, and as ever, afforded his team the luxury of staying home on shooters rather than sending extra bodies toward the paint early in the shot clock. Embiid hoisted eight threes compared to just four free throws, which indicates that a defense did a good job bottling up his post game.
Meanwhile, Philadelphia's issues against Boston's defense extend far beyond that one-on-one matchup. One problem is the Celtics' switchability, which allows them to blow up dribble-handoffs and pin-downs that Philly loves to run. Another is Boston's ability to neutralize Ben Simmons (if not turn him into an outright liability) in halfcourt sets. And finally - especially when Kyrie Irving doesn't play - a Sixers offense that thrives on exploiting mismatches doesn't really have a weak spot to attack.
A bunch of those factors collided on this crucial possession late in Tuesday's game. Before Horford made his most important (and, as Embiid would have it, most dubious) individual stop, the Celtics snuffed out a Sixers pick-and-roll. Horford showed high on Jimmy Butler, and with Simmons skulking in the corner, Gordon Hayward had no issue selling out to stymie Embiid's roll to the rim, giving Horford plenty of time to recover back to his original assignment. After Butler hit eject and reversed the ball, Jayson Tatum and Marcus Morris seamlessly switched a Butler-Harris exchange as Embiid looped around to call for an entry feed. The end result was Embiid posting up 20 feet from the hoop with six seconds left on the shot clock:
About 20 seconds of game time later, trailing by three, Philadelphia tried to work an Embiid dribble-handoff. The Celtics shut that down, too, ultimately forcing Harris into a desperation triple that Horford was all over.
Time and time again, the Sixers probed for an advantage and failed to find one.
That wasn't the case for the Celtics. A lot has rightly been made of the offensive threat posed by Philly's starting lineup, and how it offers no safe refuge for a weak defender. But the Sixers have their own defensive soft spot, and the Celtics have always delighted in poking and prodding at it. Boston relentlessly hunted J.J. Redick in this game, with everyone from Tatum to Jaylen Brown to Marcus Smart taking a turn against him in the post. (This also happened with T.J. McConnell, to a less glaring degree.)
The Sixers' offense is incredibly reliant on Redick so it's difficult to take him off the floor, but the Celtics did their damnedest to force Philly's hand. Even when they weren't scoring on Redick directly, they found ways to pick at the sore. On another one of the game's most critical possessions, Redick got himself wrenched so far out of position while trying to protect against a Smart post-up that he was boxed out of the play, and in no position to offer any resistance when Smart proceeded to set a screen for Morris. That meant Simmons had to help from the weak-side corner, which left Hayward open for a go-ahead three.
There are certainly some matchup issues for the Sixers, but a lot of this stuff really comes down to simple preparation and execution; Boston defending Philadelphia's pet plays more diligently than Philadelphia counters Boston's. So many of these head-to-head matchups over the past two seasons have been tiny-margin affairs that turn on a blown coverage or a clutch shot. The fact that Boston keeps coming out on top has long stopped feeling like chance. The Celtics humbled the Sixers in five games in last year's East semis, and humbled them again on opening night this season. The Sixers traded for Butler, but took another loss to the Celtics on Christmas Day. Then they traded for Harris, yet the Celtics downed them again.
Like any team after a blockbuster midseason trade (let alone two), Philadelphia still needs time to optimize its new configuration. Its ceiling is still as high as anyone's in the Eastern Conference, but it's concerning that so many of the same issues keep cropping up against the same opponent.
It's not like those issues simply disappear against the rest of the East's vaunted Big Four. But for every iteration of the post-Process Sixers, it's the Celtics who've posed the biggest riddle. For now, the solution remains beyond their grasp.