So the Sixers and Celtics will resume hostilities in Game 7 at Boston on Saturday.
The Celtics have a badly needed extra day of rest. They have the advantage of playing on their home floor. They have plenty of postseason experience. And they also have better players, which always helps.
The Sixers were supposed to have started their offseason two weeks ago. They nudged their way into the playoffs as an eighth seed that had been playing poorly for six weeks. They were expected to bow out meekly to the top- seeded Chicago Bulls, even after Derrick Rose went down in the opener.
They were dismissed as a mere speed bump in the path of the Celtics, who were going to take advantage of a gaping bracket to return to the NBA Finals. And they have now come to the expected end of an unexpected postseason run.
Or have they?
Because in addition to extra rest, home-court advantage, big-game experience and a locker room full of All Stars, do you know what else the Celtics have?
All of the pressure.
All of the pressure of meeting expectations. All of the pressure of winning at home. All of the pressure of their championship pedigree. All of the pressure of averting a loss that could only be categorized as unacceptable.
And if you look at their recent history, it is not a situation the Celtics have handled well.
“It’s nice to have it at home, but you have to still go get it,” Celtics coach Doc Rivers said. “At the end of the day you have to go play.”
Let’s start with Rivers, who is 3-4 all-time in Game 7. One of those came during his days in Orlando, when Tracy McGrady opened his big mouth and said he was “finally out of the first round” after the Magic grabbed a 3-1 lead. But the other six have been with the Celtics.
The first of those came in 2005, when Rivers and the Celtics capped an absolutely awful series with their third home loss. After winning in overtime at Indiana in Game 6, Boston was run off its home floor in the second half of a 97-70 loss that was as bad as the score suggests.
Celtics Nation will quickly point out that loss came before the formation of the current core, which was put together in 2008 – and hasn’t exactly been sparkling in Game 7, either.
In their 2008 championship season, the Celtics won 66 games but somehow were pushed to a seventh game by both 37- win Atlanta and 45-win Cleveland in the first two rounds.
Against the overmatched Hawks, the Celtics snapped out of it and raced to a 99-65 win. Against the one-man Cavs, Paul Pierce scored 41 points to offset 45 by LeBron James and got just enough help from P.J. Brown, who scored 10 points off the bench to cover for Ray Allen (4 points) and Rajon Rondo (8).
The Celtics had two more Game 7 affairs in 2009, when they were without the injured Kevin Garnett.
In the first round, they again were pushed to the limit by the seventh-seeded Chicago Bulls and hotshot rookie Derrick Rose before being rescued by Eddie House, who scored eight of his 13 points in the fourth quarter of a 109-99 win.
In the conference semifinals, the Celtics squandered a 3-2 lead over the Orlando Magic, ultimately losing Game 7 at home in a no-show. They led for all of 36 seconds, spent most of the game trying to cut into a double-digit deficit and collapsed in the fourth quarter, allowing the first 11 points.
Pierce, who carried the Celtics in the same spot a year earlier, made just 4-of-10 shots. The bench managed just 12 points, led by four from Stephon Marbury. Worst of all, the Celtics let the Magic to develop a comfort level, even while Dwight Howard managed just 12 points.
Boston’s most recent Game 7 was its most excruciating loss, an 83-79 road setback to the Los Angeles Lakers in the 2010 Finals. The Celtics were without Kendrick Perkins but nevertheless opened a 13-point lead in the third quarter. But Pierce and Allen shot a combined 8-of-29 and the bench managed just six points, all by Glen Davis.
Yes, the personnel has changed from year to year. But the “Core Four” has been in place for Boston’s last five Game 7’s, and some trends are worth watching.
When the Celtics have been relatively healthy, they have reached the NBA Finals. When they have been missing a key player, their playoff run ended prematurely.
Right now, Boston is without Avery Bradley, who provides overall quickness, strong 
defense, spot-up shooting and the luxury of bringing the clearly hobbled Allen off the bench. Without Bradley, the Celtics have struggled to keep the quicker Sixers out of the paint and to score with their studs off the floor.
When the Celtics have won Game 7, the reserves made a contribution. When they have lost, the bench was invisible. In Game 6 vs. Philadelphia, they had five bench points – all from Mickael Pietrus – while Pierce, Rondo and Garnett all played 40-plus minutes. Someone on the bench is going to have to step up Saturday and fill the role previously played by Brown, House, Davis and James Posey.
Who is that player? Pietrus seems like the most likely candidate. But if he’s launching bricks, can Keyon Dooling or Ryan Hollins or Marquis Daniels or Greg Stiemsma contribute something other than fouls? It seems unlikely.
And when the Celtics lost Game 7 to the Magic, their normally stout defense disappeared. At home against the Sixers, they made a stand late in Game 1 and in the second half of Game 5. But for the most part, Philadelphia has not had trouble using its quickness, getting its drive-and-kick game going and taking advantage of Boston’s lack of a shot-blocker.
After losing Game 6, Rivers said, “I do like that we have an extra day. I think that helps us a little bit.” And the Celtics are 2-0 this postseason with the additional off day.
But that alone is not going to get it done. Neither is the home court, which the Sixers have solved already. And the experience will help only if the Celtics can call upon it; at times it has been fleeting, as it was Wednesday night.
The Celtics need to play more through Garnett, who cannot shoot 3-of-12 as he did in Game 4. They need the 22 points Pierce has averaged in the last four games, not the 21 combined he had in Games 1 and 2 at home. They need Rondo to be both a scorer and playmaker, not one or the other. They need Allen to provide timely shooting and something more than matador defense. And they need someone – anyone – on the bench to do more than resemble a statue.
And the Celtics have to do this against the Sixers, who already know they can win in TD Garden, currently own the momentum, are playing much closer to their potential and have absolutely nothing to lose and everything to gain.
No pressure, guys.
Chris Bernucca is a regular contributor to SheridanHoops.com. His columns appear Wednesday and Sunday. You can follow him on Twitter.