The Boston Celtics are once again under intense postseason scrutiny after their shocking playoff collapse against the Philadelphia 76ers, a defeat that has now placed head coach Joe Mazzulla in uncomfortable historical company alongside former Celtics coach Doc Rivers.
The series, which Boston entered with control and expectation, unraveled in dramatic fashion as the Celtics became the first team in franchise history to blow a 3–1 series lead. The loss not only ended their playoff run but also reignited long-standing debates about Boston’s history of postseason collapses when holding commanding advantages.
Mazzulla’s failure now sits in a broader historical context that Celtics fans know all too well. Doc Rivers, despite winning a championship during the Kevin Garnett–Paul Pierce–Ray Allen era, is still often remembered for multiple playoff collapses during his tenure. Most notably, Boston lost after holding 3–2 series leads on three separate occasions during that era: the 2009 Eastern Conference Semifinals against the Orlando Magic, the 2010 NBA Finals against the Los Angeles Lakers, and the 2012 Eastern Conference Finals against the Miami Heat.
Each of those series carried different circumstances, including injuries and elite opposition. In 2009, Boston was already missing key depth pieces, and Orlando capitalized late. In 2010, Kendrick Perkins’ injury early in the Finals shifted the balance of the series. In 2012, LeBron James delivered one of the most dominant Game 6 performances in NBA history to force and eventually win Game 7.
That context has often softened criticism of Rivers, with many pointing to roster limitations and elite competition as mitigating factors.
Mazzulla, however, has not been afforded the same benefit of the doubt.
While Boston did face the absence of Jayson Tatum late in the series due to injury, critics argue the damage was already done long before that point. The Celtics’ inability to close out games earlier in the series, combined with inconsistent tactical adjustments, has placed the coaching staff under heavy fire. The collapse is being viewed not as a single moment of bad luck, but as a prolonged failure to maintain control of a winnable series.
Analysts have been quick to highlight that while injuries played a role, they do not fully explain how a team with championship expectations allowed a lower-seeded opponent to claw back from a 3–1 deficit. The 76ers capitalized on Boston’s late-game lapses, exposing defensive breakdowns and execution issues that persisted throughout the series.
For Mazzulla, the implications are significant. While his job is not currently believed to be in immediate danger, the narrative surrounding him has shifted. What was once seen as a promising coaching tenure is now being questioned under the weight of postseason failure. There is growing pressure for accountability, particularly given Boston’s win-now roster and championship expectations.
The Celtics’ early exit also reopens broader organizational questions. With a roster built to contend, repeated playoff shortcomings raise concerns about whether coaching, execution, or roster balance is the primary issue preventing postseason success.
For now, Boston is left to process another devastating playoff collapse—one that not only ends their season but also places Joe Mazzulla in a lineage of Celtics coaches whose postseason failures are remembered just as vividly as their successes.
