Let’s start with the obvious: The Celtics had no business winning this game. They shot 45 percent, missed 10 of 14 3-pointers, turned it over 18 times and clanged 11 free throws. Not that the Pistons were much better, but they were the ones with an eight-point lead and less than eight minutes to play.

The Celtics did find a way to win, 86-82 (click here for a full recap), and that more than anything offers a glimpse at just how different this year’s Celtics team is than last year’s. Time and again those Celtics found themselves in that position last year and they never did find a way to make the plays until May.

There are all kinds of reasons for this – starting with better health for Kevin Garnett and Paul Pierce – but the real takeaway from the first half of the season is that the Celtics really are gunning for homecourt advantage, and they suddenly have a great chance of reaching this goal. 

“Every game is important for us to try to win, especially establishing our homecourt,” Pierce said. “All these games, no matter who we’re playing, are big because when you look at the standings it’s going to come down to the end of the year.”

The Celtics now have a three-game lead on Miami (four in the loss column), and while that’s certainly not insurmountable with 41 games left, it’s an enviable position.

“Record-wise, obviously I’m happy,” Doc Rivers said prior to the game. “I always think we should have won more, but you never count the ones you probably should have lost. You only count the ones you thought you should have won.”

This was one they should have lost and when you win enough of these kinds of games you put yourself in a position to do the kinds of things you hope to accomplish in the second half of the season. Last year’s Celtics couldn’t make that claim. The evidence, after a half season of basketball, is looking far more positive.

Here are three other points from an ugly, but satisfying win.

SHAQ SAVES HIS BEST FOR LAST

Shaquille O’Neal looked up at the scoreboard and saw that his team was down eight, so he figured he better do something about it. Shaq doesn’t usually play in the fourth quarter, but the situation called for something drastic.

First he got an alley-oop dunk from Rajon Rondo. Then a layup, then a steal that led to a Pierce layup. After a timeout, he finished off a three-point play that brought the Celtics even. The only thing he didn’t do was make his free throws when the Pistons went into hack-a-Shaq mode with three minutes left.

“I was ready to shoot them,” O’Neal said. “They just didn’t go in. If we had lost the game I’d have been really upset. Keep in mind, when we really, really, really need them, I’ll be there and you don’t have to worry about it. Studies show.”

Studies, or at least recent statistics, also show that Shaq has pulled himself out of a prolonged slump, and when the Celtics really, really need him he has been there. He had a huge game against Charlotte when they were down to him and hope at center. He battled Dwight Howard on Monday and he absolutely won the game Wednesday night.

“Shaq was the difference in the game with his energy,” Rivers said. “His size and energy. Shaq, he won the game for us tonight. He did all the little things. Crashed the glass, was physical, blocked shots, he was absolutely wonderful tonight.”

The Celtics never know what they’re going to get out of the big fella on a day-to-day basis. But give him this: He has played in 32 of their 41 games and with all the injuries up front it’s fair to suggest that they would be a mess without him.

THAT FOURTH QUARTER MAGIC

It’s tempting to suggest that the Celtics are playing with fire with the way they’ve played games recently. They allowed the Bobcats and Pistons to hang around far too long and then turned it on with late defensive stands.

“Fourth quarter for some reason is when we peak,” Kevin Garnett said. “All the things that happen the three quarters before don’t even matter. As long as we’re still in the game and the game is reachable and there’s time on the clock, we feel like we have a chance to win.”

That quote seemed like a bit of a head-scratcher coming from Garnett who prides himself on playing hard all the time.

“I’ll translate,” Rivers said helpfully. “What he’s saying is, when we do struggle in games we still think we’re going to win the game.”

That makes more sense and gets to a larger issue. The Celtics are re-establishing their identity as a team that not only knows how to win, but doesn’t panic when things get tight and actually accomplishes the feat. Again, that’s not something that could be said last season.

And the Celtics were bad. Real bad. They somehow shot 29 percent in the third quarter and turned it over nine times but we’re still in the game.

“Listen, nothing was working today,” Rivers said. “We were bad. Our execution was bad. As good as the ball moved the other night it was the exact opposite today. We always say shoot it, pass it or drive it but don’t massage it. The ball should feel great. It got a great massage the entire game.”

The numbers may not show it, but the Celtics were also out of sync defensively, as well. The Pistons presented a handful of interesting defensive assignments with Tracy McGrady playing 30 minutes at guard and Tayshaun Prince guarding Rajon Rondo.

That is known colloquially in the NBA as a cross-switch where players guard someone other than the man who is guarding them, and it messed with the Celtics defensive rhythms. 

“The game was just strange,” Rivers said. “We switched more tonight than we did the entire season. We’re not a switching defensive team. It’s not who we are. It’s not what we do.”

So, the coach made a halftime adjustment: Don’t switch.

And when the game was on the line and they needed a shot they turned to the guy who was 1-for-7. “I always feel like the next shot’s going in,” Ray Allen said who did in fact make it. Of course.

You take what you can out of the dreary days in January and the Celtics took a game they shouldn’t have won and came out with a victory.

JERMAINE O’NEAL MAY HELP AFTER ALL

The weather delayed Jermaine O’Neal’s decision by a day, but after all the information was pored over by O’Neal, team president Danny Ainge and the Celtics medical staff, they decided to delay surgery on his left knee.

O’Neal will take the next four weeks to rehab and strengthen the muscles around the knee. It’s not an optimal situation, but this may be the best-case scenario for all involved.

“This is a good option,” Ainge said. “Either way we thought that he might be back for the playoffs. He’s got a lot of wear and tear on the knee. I think he feels like if he gets in better shape and [stronger] he’ll be ready to give us an effort we haven’t seen this year out of him.”

Ainge said the surgical procedure under discussion was a “cleaning out” of the knee and not to repair ligament or cartilage damage. The best guess was it would have kept O’Neal out eight weeks, which would have made it difficult for him to come back and get in rhythm for the playoffs.

O’Neal will probably still need surgery at some point. He missed 19 games earlier this season and may have come back too soon. “He might have overdone it,” Ainge said. “He wasn’t in as good a shape as he could have been. Maybe [he] came back a little too soon. All those things are possibilities.”

The Celtics will likely get Kendrick Perkins back in the beginning of February. If he can come back strong, and if they can hold on until that point, then they may be able to weather this stretch.

As for O’Neal, Ainge was optimistic that he can return at full strength. “The purpose is to get him ready in late-season and postseason play with no restrictions,” he said.

It looked doubtful last week, but just maybe the Celtics will have their three-headed monster at center ready for the playoffs.