The Celtics overachieved all season, but their collapse against the 76ers raises big long-term questions

Boston has been kicking Philadelphia's ass for going on a decade now. If the Celtics are suddenly vulnerable against them, does it mean they're vulnerable against everyone else? Are these minor, fixable flaws, or do they need to consider something more drastic to address all of this? Let's try to figure out what went wrong here and what steps are needed to get the Celtics back on track for genuine championship contention.

Boston's math problem

The Celtics are built to win the math problem. The fundamental principle on which they are built is that if they get to take more shots than their opponent, and if those shots are higher-value shots than the ones their opponent is taking, then they should win far more often than they lose. They attempted 283 more total field goals than their regular-season opponents because they had the NBA's third-highest total rebounding rate and third-lowest offensive turnover rate. They had the league's fourth-highest 3-point attempt rate a year after becoming the first team ever to shoot more 3s than 2s. More shots and better shots tend to lead to more wins. If a playoff series lasted 10,000 games, Boston would almost always win it.

Of course, it doesn't. The playoffs are a much smaller sample and, therefore, much more prone to variance. The Celtics relearn this almost every spring. Look at their losses against Philadelphia. Boston shot below 30% on 3s in all four of their losses to Philadelphia. That probably sounds familiar. The Celtics shot 25% from deep in Games 1 and 2 of the Knicks series last year, two games in which they blew 20-point leads. In the 2023 Eastern Conference Finals against Miami, in which they fell behind 3-0, they shot 30.3%.

That's three series the Celtics lost as heavy favorites because the 3s stopped going in. This season as a whole, the Celtics went 44-6 in games in which they made 35% of their 3s, but 15-24 in games that they didn't, as noted by Yahoo's Kevin O'Connor. Boston doesn't have another pitch offensively. They scored the fourth-fewest points in the paint in the regular season, and no one had a lower free-throw rate. Meanwhile, their possession advantage tends to shrink in the postseason. Mitchell Robinson and Karl-Anthony Towns killed them on the glass in the Knicks series last year. The 76ers turned the ball over almost as rarely in the regular season as the Celtics do, and did so less in this series. Suddenly, Boston isn't taking more shots than its opponent and, while the shots they do take are more valuable on paper, they're not nearly as stable in a playoff setting.

If Joe Mazzulla has a weakness as a coach, it's how stubbornly he tends to cling to his big-picture vision. If Boston had attempted to minimize variance with its huge leads against the Knicks last season by taking shots that were perhaps less valuable but ultimately easier to make, that series was winnable. Game 2 of this series was lost in part because of how strictly Mazzulla adhered to his deep-drop pick-and-roll defense. When Philadelphia screened for its guards, Boston's big men hung back near the room. That suited Tyrese Maxey and VJ Edgecombe just fine. They made 11 3s, six of which were, according to NBA.com tracking data, wide open. The numbers said those were the shots Boston should want to give up, so they did, and Philadelphia just kept making them.

A quietly depleted roster

This raises another issue: talent. The Celtics spent the last two seasons with one of the deepest rosters in NBA history. You could argue they had six All-Star-caliber players when healthy in Tatum, Brown, White, Jrue Holiday, Kristaps Porziņģis and Al Horford. Payton Pritchard and Luke Kornet were starting-caliber reserves. They had more schematic flexibility with those eight players than perhaps any team in NBA history. Need to bring your big man up to the level of the screen? There's no coverage Horford couldn't run. Want a stationary rim-protector? Porziņģis is a giant with great instincts. Need a great one-on-one defender to throw at an opposing guard? Holiday is going to make the Hall of Fame doing that.

All three of them are gone. So is Kornet. They were victims of the collective bargaining agreement. Boston was in line for a half-billion-dollar roster when last offseason began. They let those four go in order to stay below the second apron, a reasonable choice given the realistic possibility of a gap year, but then, at the trade deadline, they took things a step further. Boston didn't just duck the aprons; they ducked the luxury tax altogether by turning Anfernee Simons into Nikola Vučević and dumping several minimum contracts.

This was obviously a financially motivated decision, but it was a strategically sound one. The Celtics were repeat taxpayers right as the repeater tax formula grew significantly more punitive. However, by getting below the tax this year and staying below next year, the Celtics can reset their repeater tax clock entirely, essentially allowing them to spend with impunity for the rest of the decade after the 2026-27 season. With Tatum injured at the time, prioritizing the flexibility to spend during his future was the strategically sound decision. It also left a deceptively limited roster shorthanded in the present.

The Celtics made lemonade all year with talented but flawed players. They have Mazzulla's coaching to thank for that. Neemias Queta was a rim-protecting force for Boston. The Celtics hesitated to let him defend closer to the level of the screen because that just isn't his strength. He's not Al Horford. He's a minimum-salary player who has vastly outperformed expectations, but he was available for the minimum for a reason. His defensive limitations and his propensity for fouling were big problems against Philadelphia.

Perhaps the Celtics could have supplemented him with a different sort of backup center, but they were limited in terms of what kind of contracts they could bring in. They needed Simons to be the matching money in the deal and they needed to save money to get below the tax line. Without giving up significant draft capital, that left Vučević as their pick. The hope was that his offense, especially his shooting, would contrast well with Queta's. But he's been vulnerable defensively for his whole career, and the Celtics found no way of addressing that. Their best bet might have been more minutes with Tatum at center, but that's precarious in a series against Joel Embiid, and either way, the Celtics may not have wanted to take the beating that comes in a small-ball 5 role.

Losing Simons deprived Boston of a badly needed source of speed and creation, especially since White struggled so mightily for most of this series. His jumper has felt broken all season, pretty problematic for a point guard who never touches the paint or gets to the line. His inability to meaningfully penetrate the Philadelphia defense cost him a lot of his playmaking in this series, too.

He's not quick enough to defend Tyrese Maxey -- few players are -- but having to take on that matchup somewhat cost him his ability to affect games defensively in the ways he usually does. White isn't a point-of-attack stopper; he's a genius help-defender. He averaged 2.5 deflections per game in the regular season, a figure that has basically been cut in half in this series. But he had to guard Maxey because Holiday is no longer on the roster. The only reserve who's had much success in the matchup is Jordan Walsh, for whom Mazzulla is seemingly hesitant to play for offensive reasons.

Never was the talent drain more evident than it was for Game 7. Mazzulla kept only two of his Game 1 starters: White and Brown. The three others? Baylor Scheierman, who hadn't played more than 15 minutes in any game this series, Luka Garza, who hadn't played more than 14, and Ron Harper Jr., who was playing on a two-way contract until early April. Mazzulla just didn't have the tools that he used to. He was grasping for something, anything, to help him overcome Tatum's Game 7 absence. After all, Tatum has carried the Celtics through plenty of playoff pickles.

You can overcome a lot when you have a top-five player in the NBA to Superman you through the biggest games as Tatum so often has. Game 6 facing elimination on the road against Milwaukee in 2022? A 46-point explosion. Game 7 against Philadelphia in 2023? How does 51 sound? It's gotten lost because of the Achilles tear, but Tatum put up 42 at Madison Square Garden in Game 4 of last year's loss to New York. When the chips are down, the Celtics have been able to Tatum their way out of many difficult situations.

For most of this season, it was Brown wearing the cape. It just didn't prove sustainable. Brown shot over 71% in the restricted area and nearly 50% on mid-range shots through the end of December. In the rest of the season, that fell to around 67% in the restricted area and 33% on mid-range shots. His effectiveness as a driver in the Philadelphia series was sapped because officials were stricter about policing his use of his off arm to create space. He performed admirably in Tatum's absence on Saturday, scoring 33 points and nearly carrying the Celtics to a comeback, but he's never quite reached the highs Tatum did at his peak. The player Brown was early in the season might have flirted with this territory. That's the only time in his career that was ever really true. If there's a player on this roster capable of consistently reaching the level of superstardom NBA champions tend to need, it probably has to be Tatum.

Can he still be that guy? His recovery from that torn Achilles was an undeniable success, despite the knee stiffness that kept him out of Game 7. He's further along than anyone could have imagined. But one of his superpowers was durability, and his absence on Saturday was a reminder that Boston may need to be more cautious with him going forward. Knee stiffness is scarier after Achilles surgery.

Plenty of players, even healthy ones, start to lose a step physically as they hit their late 20s. Tatum isn't Kevin Durant. He's not an all-time shooter. He's more dependent on physicality to create offense, and if he's even 95% of his old self moving forward instead of the no-brainer First-Team All-NBA player he's been in the past, that poses real problems for the Celtics. They aren't historically loaded anymore. If they're going into battle with the 11th-best player in the league instead of the fourth-best player, they're not going to be able to paper over these structural vulnerabilities as easily, and without the resources to rebuild one of the greatest teams of all time, they're not going to be able to overwhelm less-talented opponents as easily anymore either.

What does Boston have to work with going into the offseason?

The Celtics aren't completely depleted. If they want to tinker on the margins, they can. They're about $10 million below the tax line right now, but can pretty easily create the full mid-level exception while staying below it by dumping some minimums and perhaps trading out of the first round. That won't get them a big-ticket free agent, but should yield someone who can help. A reunion with Simons makes plenty of sense or, if they want a defensive-minded big, perhaps they'd bring back Robert Williams III while planning to limit his minutes through the presence of Queta and Luka Garza.

They have more picks to trade than you'd think. Their 2032 first-round pick is frozen because they finished last season above the second apron, and their 2029 pick is owed out through the Holiday trade, but they can deal the No. 27 overall pick this year, their 2027 pick, and then their 2031 and 2033 selections. Their bigger problem, at least where a trade is concerned, is matching salary.

Let's assume for now that Tatum and Brown are staying put. Boston's fourth-highest-paid player is Sam Hauser at just below $11 million. Pritchard makes below $8 million and is probably borderline untouchable just on value. No one else is above $3 million. Adding, say, a $20 million player is doable, but probably deprives them of a good chunk of their mid-level flexibility in free agency. They have two workarounds.

The first is the $27.7 million trade exception they got from giving up Simons. They could use that to add a major piece. Doing so would almost certainly mean going above the tax line -- at least if they do so without offloading other salary. The Celtics are allowed to do so, but again, after all of the effort they put into getting below the tax this season, it would seem wasteful not to reset the repeater clock. The Celtics are so close to being free to spend for multiple years. They just need one more year of patience. Still, trading Hauser and picks for a player in the $25 million range is doable, and if the right center is out there, it might be worthwhile. I'd keep an eye on Myles Turner -- who just barely fits in the exception -- considering Boston's history with shooting big men, though his defense has certainly slipped.

The other option is considering a Derrick White trade. This would have been more lucrative last summer, when the Raptors reportedly dangled the pick that became Collin Murray-Boyles. Other teams might have offered multiple picks. The Celtics passed. They wanted to maximize their present window. Well, after a first-round loss, do they reconsider and perhaps take a slightly longer view? White will make around $30 million next season. He's not going to net the monster haul he might have had a year ago. This was his age-31 season, and the shot is now a big question mark. But Kenny Atkinson called him a top-five player in the NBA somewhat recently. Plenty of advanced metrics are just as bullish. There would be a lot of interest.

Minnesota makes some sense. The Wolves are thin at guard now that DiVincenzo has a torn Achilles tendon, but their frontcourt is deep and potentially getting deeper with No. 17 overall pick Joan Beringer showing promise as a rookie. Could there be a Rudy Gobert swap here? He's two years older than White, so Boston would probably want more in the deal, but he'd certainly address any defensive questions the Celtics have. White would be Steve Kerr's dream backcourt partner for Stephen Curry. Maybe a deal could center around the Golden State's lottery pick if it doesn't jump into the top four, though the Warriors likely wouldn't consider giving up such a huge package for a role player unless they knew they were getting a star in some other way.

I wouldn't consider a White trade likely, though. He's probably more valuable to Boston than he is to any other team, considering how much of their style is built on his strengths. Moving him means reimagining some of the fundamental principles on which your team is built.

And if they're willing to do that, it's worth revisiting a question that was beaten into the ground before the 2024 championship: is there anything that could convince the Celtics to split up Tatum and Brown? The answer is mostly no, but perhaps technically yes. You don't trade Brown for just anyone. You don't even trade him for a star on the same level. Brown has so much accumulated organizational equity that you're not going to trade him for, say, Donovan Mitchell. Trading away a lifer, sacrificing a decade of continuity, that's not something you do for a shakeup. It's something you do when you're reconceptualizing your team on a grander scale. If you're trading Jaylen Brown, it means you're not only getting someone back who's better than he is, but probably better than Tatum too. There's really only one name we expect to be available that fits that bill.

Let's have the Giannis conversation

In April, The Athletic reported that the Celtics "are known to be interested" in two-time MVP Giannis Antetokounmpo. It felt like an odd report at the time. Boston was thriving. Brown had snuck into the fringes of the MVP conversation, and the Celtics had resisted quite a few overtures to move him in the past. But it stood out because, a day earlier, Antetokounmpo went out of his way to praise Mazzulla.

"Like, you saw I talked with coach Joe Mazzulla," Antetokounmpo told the Milwaukee Journal-Sentinel. "I said, 'You had so many opportunities to make excuses, but you didn't.' And he said, 'Oh, they're good players.' I said, no. It's about the mentality that you instilled in your place."

Reports have suggested that Antetokounmpo's goal, if he leaves Milwaukee, would be to pursue a second championship above all else. His preferred destination has seemingly been the New York Knicks, but they have little to trade that would interest the Bucks, and with the Celtics now out of the playoffs, they're arguably the Eastern Conference favorites. They may not be in a position to trade for Antetokounmpo.

[Resetting the Giannis Antetokounmpo trade market: Why 18 teams are plausible suitors

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You've heard other teams like Miami or Golden State. In the past, they might have made sense. It's what stars tend to do: seek out warm, glamorous markets and let the chips fall where they may. If your goal is a championship, that's not going to cut it anymore. Those Thunder and Spurs have set the bar too high. Antetokounmpo's best path to a championship is picking the best possible Eastern Conference team he can find, avoiding OKC and Victor Wembanyama until the Finals, and then beating whoever escapes the seemingly inevitable conference finals series they'll play in each of the next few springs.

If the Knicks are off the table, that's probably Boston. We know he respects Mazzulla's culture. Tatum would be a perfect co-star for him for many of the same reasons Khris Middleton once was: he's a traditional shot-maker who can take over late in games, but he impacts games in a variety of ways that don't necessitate enormous overall usage. But more than anything, the two sides are extremely stylistically compatible.

The Celtics keep losing in the playoffs because they can't pressure the rim. Who pressures the rim more than Antetokounmpo? Giannis needs shooters around him to generate space for his driving. The Celtics obviously emphasize shooting as much as any team in the NBA. There would be minor kinks to work out. Queta isn't a shooting center, for instance. Boston has Garza and could bring back Vučević, but may need to seek out someone better for that role. The Celtics would also probably prefer to add a point-of-attack defender somehow as well. Brown frequently guards opposing stars, so Boston would probably need a replacement. These are solvable problems.

Antetokounmpo is two years older than Brown. He's also a much bigger injury risk. This isn't as simple as pairing two megastars and waltzing to the Finals. It's a debate between trying to maximize an existing and extremely successful partnership or potentially building a better one that may not be quite as sturdy or enduring. The Celtics know they can win a championship with Tatum and Brown because they've done it. That certainty wouldn't come with Antetokounmpo.

If Boston hadn't just lost in the manner in which it just did, this would be a pretty easy "pass." You don't break up a Finals team on this sort of bet. But this is the sort of loss that triggers existential questions. Perhaps on paper, this Celtics season was a relative success considering what we all expected. In practice, blowing a 3-1 lead to the 76ers would force almost anyone to reexamine their identity. Does Boston's regular-season formula still translate to the postseason? Do they have the resources to rebuild the monstrous supporting cast they had in 2024? If not, are Brown and Tatum capable of winning a championship with a more typical overall roster?

It's the highest-stakes floor vs. ceiling debate any NBA team is likely to have in quite some time. The best version of a hypothetical Antetokounmpo-Celtics team would be better than the existing one because Giannis is a more impactful player than Jaylen Brown, and the better your best player is, the less you tend to need elsewhere. Holiday was the fifth-leading scorer on the 2024 Celtics. He was the third-leading scorer on the 2021 Bucks. Boston is paying two 35% max contracts either way. One way to work around the limitations those contracts impose on your ability to spend elsewhere is to maximize what you're getting out of the big contracts so you don't need as much out of the smaller ones.

But the worst-case outcomes, especially when you factor in the extra draft picks you might have to put into the trade and any others you'd spend retrofitting the roster around your new star, are significantly drearier. Boston turned down a similar type of trade for Kevin Durant a few years ago, partially to avoid those worst-case outcomes, but also because of how optimistic they were about Brown's best ones. They felt they were close. They were right. Now they have to decide if that's still true, and blowing a 3-1 lead to a team they've handled for years is the most compelling argument they've ever faced that they no longer are.