Well, they survived.

That about does it for the positives Boston can take away from its second-round series against Cleveland, as they barely outlasted the Cavs 97-92 in Game 7 on Sunday.

Although the epic scoring battle between Paul Pierce and LeBron James made it one of the more exciting playoff games in recent memory, the Celtics have to be asking themselves how it got to that point.

Boston, remember, was 66-16 in the regular season, with one of the best scoring margins (+10.3 per game) of all time. Cleveland, meanwhile, was just 45-37 and gave up more points that in it scored. On paper, this should have been a blowout.

Instead, the Celtics were lucky to survive. Cleveland outscored Boston by eight points on the series, including a 24-point blasting in Game 3. All but one of the four games in Boston’s TD Banknorth Garden were white-knucklers; had Cleveland won any, it would have walked away with one of the biggest upsets in NBA playoff history.

Boston is now just 8-6 in the playoffs and has yet to win on the road, surviving solely due to the home-court advantage it earned during the regular season. While it was easy to label the first-round seven-game series against Atlanta as a fluke — Boston’s four wins were laughers, and each of the three losses were games they could have easily won — the Cleveland series is much harder to dismiss.

Instead, some real questions are cropping up about Boston’s ability to replicate its regular-season success, from Kevin Garnett’s willingness to take big shots to the supporting cast’s ability to dial it up in the postseason.

But the biggest question is Ray Allen. The third member of the so-called “Big Three” has instead morphed into the Invisible One. He’s shooting only 37.6% for the playoffs and has averaged a meager 9.2 points a game in the Cleveland series. So out of sorts was Allen during the Cleveland series that when Boston coach Doc Rivers benched him for all but 1:38 of the fourth quarter in Game 7, nobody even questioned the move. Other Celtics, most notably Eddie House and James Posey, simply were playing better.

At least Boston’s trademark defensive intensity hasn’t slackened. The Celtics allowed only 85.1 points a game from Cleveland, after yielding just 87.1 against Atlanta. For the playoffs, their Defensive Efficiency mark of 97.3 points per 100 opponent possessions is easily the league’s best, just as it was during the regular season.

Nonetheless, the Celtics’ offensive woes are a major story heading into the Eastern Conference finals against Detroit. The Pistons had a few stumbles of their own, falling behind 2-1 in the first round against the lightly regarded Sixers and then being beaten by 25 points in Game 3 in Orlando in Round 2.

But unlike Boston, they appear to have righted the ship. The Pistons won the final two games against the Magic, even with All-Star point guard Chauncey Billups out with a hamstring injury, and have won seven of their past eight playoff games.

Additionally, Detroit would seem to have a couple of matchup advantages against Boston. At the point, Billups has obvious edges in size and experience against the Celtics’ Rajon Rondo. Although Rondo is the superior defender, the difference isn’t large in that area, whereas Billups’s offensive skills are miles beyond Rondo’s.

On the wing, Richard Hamilton appears to have a similarly large advantage on Allen. Never regarded as a great defender, Allen will have to chase Detroit’s leading scorer through myriad screens to try to neutralize his midrange scoring game. If Allen can’t counter with some 3-point bombs of his own, don’t be surprised if another Allen — little-used Tony Allen, a stalwart defender — sees bigger chunks of playoff time as the series goes on.

The other wing is also an opportunity for Detroit. Tayshaun Prince may not be able to match Pierce point for point, but the long-armed defender made life miserable in the first two rounds for Philadelphia’s Andre Iguodala and Orlando’s Hedo Turkoglu. If he can inflict similar misery on Pierce, then any offense the Pistons get from Prince is a bonus.

Detroit also has a long-armed defender to put on Kevin Garnett in the form of Rasheed Wallace. While Wallace can come unhinged emotionally at some times and disappear completely at others, he’s one of the few players in the league who can match Garnett’s length and challenge his shots, and he seems to play his best against opponents he deems worthy of his attention.

Detroit also has advantages further down the roster. At center, Antonio McDyess is a far more accomplished player than Kendrick Perkins, and frontcourt subs Jason Maxiell and Theo Ratliff seem to be near-matches for Boston’s Leon Powe and P.J. Brown. Off the bench, point guard Rodney Stuckey has been a revelation as a rookie, offsetting whatever Boston may get from House and Sam Cassell.

All of this may lead to the conclusion that I’m picking Detroit … but I’m not. Although the Pistons can throw two strong defenders against the Celtics’ two best players, the two forward spots still loom as advantages for Boston. Additionally, Allen may not play nearly as badly as he did the last round, and aside from those in the point guard position, the advantages Detroit does have are quite small.

Finally, there’s the defense. Detroit is no slouch itself in this department, but Boston’s swarming defense has held all comers far below their season norms. Garnett won Defensive Player of the Year, but at least as important has been the five-man defense — no unit has been more cohesive, a tribute to Rivers and defensive assistant Tom Thibodeau.

Of course, several Celtics are outstanding individually too, including Garnett, Rondo, Perkins, Brown, Posey, and Tony Allen. Put them together in a great team concept and it requires a tremendous individual talent — such as King James — to overcome them. Detroit has no player in that class, and as a result it’s likely to struggle to score all series.

Even if they don’t, Boston has one other edge to lean on — its home court. As with the past two series, the Celtics would play a seventh game in TD Banknorth Garden. Once again, they may need it, even if they finally manage to win a road game this series. But when the dust settles and the smoke from all those pregame fireworks clears, I expect the Celtics to be left standing as the Eastern Conference champions.

jhollinger@nysun.com