MIAMI – Eighty eight and zero. In the history of the NBA there have been 88 playoff series that began with one team winning the first three games and each time that team has gone on to win the series. That’s the situation the Celtics find themselves in after winning the first three games of their first round series with Miami.

But there’s always that one (ask the Yankees) and the Celtics have no desire to be that team.

“It ain’t over,” Doc Rivers said Saturday afternoon. “You got to win it. You got to win four games. You don’t win three, you have to win four. To me it’s just that simple.”

The Celtics have said all the right things leading up to Sunday’s Game 4 in Miami. Paul Pierce called it a “must game,” and referenced a boxer who loses the first 11 rounds and lands a knockout in the 12th.

Ray Allen used the analogy of a marathon runner. “You’re not done until you cross the finish line,” he said. “So we have a finish line and we have to cross it.”

Leave it to Kevin Garnett to lay it down in the simplest terms possible.

“At this point right now, man, we’re focused on the Heat,” he said. “We’re not looking past this game. I’m not even going to indulge in any of that conversation. The focus right now is trying to win this game in Miami.”

The easy call is that this game is a matter of motivation. Can the Heat summon the energy to try to begin the long climb out of this hole, knowing that for many of them it will be their last games in a Miami uniform? On the other side, are the Celtics ready to end it knowing they have Game 5 back in Boston in their hip pocket?  

But there’s much more to this series than just that. Game 3 was a 50-50 affair and left Rivers with ample material to engage his team. Game 1 could have been Miami’s if not for a spirited Celtics rally. Outside of Game 2, this has been a competitive series, as were all three regular season games between these two teams.

Motivation may indeed come into play if one or the other grab a sizeable lead, but until the game develops here are five things to watch for as the Celtics look to close things out in South Beach.

THE SUBTLE GENIUS OF RAJON RONDO

Lost in the dramatics of Paul Pierce’s game-winner, Ray Allen’s Game 2 explosion and even Tony Allen’s brilliant defense on Dwyane Wade in Game 1 has been the stellar play of Rajon Rondo.

Through three games Rondo has averaged just 11.7 points, but that never tells the full story with him. He’s also getting 10 assists a nights and 6.3 rebounds, but again, numbers can’t define Rondo.

Rather, it’s been his ability to run the offense for over 40 minutes a night that has been the catalyst for the Celtics offensive execution.

“He’s been terrific,” Doc Rivers said. “When everyone was injured, literally, Rondo had to do a lot of scoring. But since Ray and Paul and Kevin [Garnett] are back and in rhythm, he’s more of the facilitator. But he does the best job of a guy you could ask to do it. He’s been huge in this series.”

Take the closing minute of Game 3. On the possession before Pierce’s jumper, Rondo had two options at his disposal: Allen coming off a flare screen with Garnett, or Pierce on the opposite side. He chose Allen for a corner 3 and it was a great look, it just didn’t go in.

Heat coach Erik Spolestra had some media people shaking their heads after Game 3 when he said that the reason the Celtics were so tough to defend is because they have so many crunch-time options. In other words, didn’t he know the final play was going to Pierce? Well, no. He didn’t. See the previous possession.

It’s that decision-making that has lifted Rondo’s game into the upper stratosphere of elite point guards.

“He’s light years [ahead of where he was], but a lot of that is just age, maturity,” Rivers said. “The other part of it is system. He’s been in the same system his entire career. I thought Game 3 was the best play-calling game in his career. He was like [Jason] Varitek as far as calling the right pitch. He was phenomenal. That’s where he’s improved. He know what I’m thinking. He’ll call a play and you can sit down and it’s terrific.”

Rondo’s defense has also been huge in this series. When he picked up his third foul late in the first half of Game 3 it negated his ability to pressure the ball fullcourt and allowed the Heat to get back in the game.

“The third foul hurt us because he could no longer pressure the ball,” Rivers said. “That really hurt us. He played a forty-whatever minutes, he’s just been fantastic for us.”

HOW MUCH DOES DWYANE WADE HAVE LEFT?

The word from the Heat camp is that Wade will play in Game 4, but that the leg cramp he suffered late in Game 3 has been painful.

Wade has been sensational in this series. He literally does everything for Miami on offense and once he lost the ability to attack the basket, the Heat were just operating on hope.

He is the single biggest reason the Celtics are eyeing Miami warily.

“I’m looking at it like it’s a 3-3 tie,” Pierce said. “It’s a must game for us. We want to be desperate for this win. We don’t want them coming back to Boston with any kind of confidence. You never know what can happen in this league. They’ve got a great player in Wade and a team that played well down the stretch.”

If Wade isn’t 100 percent, or at least reasonably close to that number, it will be very difficult for Miami to win. So much of what he does (and what he does for his teammates) is predicated on his ability to break down defenses and attack the basket.

LeBron James may be on another planet, but Wade is as good as it gets on this one. The smart money is that he will wind up staying with the Heat this summer when he becomes a free agent and they are finally able to put a team around him that compliments his skills.

“He’s probably is thinking about this is where he won a championship,” Pierce said. “It would be nice to see him a Boston Celtic uniform though.” Pierce was laughing as he said it, and while it is beyond far-fetched, it would be nice.

KENDRICK PERKINS REMAINS GROUNDED

Once again the rest of the world is coming to find out just how important Perkins is to the Celtics. He has completely dominated Jermaine O’Neal, which has helped the rest of the Celtics lock in on Wade.

But the guy can’t win for trying sometimes. Even when he’s happy, he looks grumpy. But he was genuinely ticked off at himself after missing a couple of easy shots in Game 3. Perkins had one of the strangest lines in basketball history: No points, 0-for-4 shooting, 12 rebounds, five turnovers and two blocks in 30 minutes.

“We got on him a little but [Friday] night because he had the shoulder slump in full mode over missed layups,” Rivers said. “We just keep reminding him of all the positive things he does for us on the floor. When he does that job great then we’re a good basketball team.”

Still, no one likes to miss shots, especially shots they should make.

“I’m a guy who will focus on doing my job to the fullest,” Perkins said. “Everybody goes through a hard game where they don’t make shots so I was a little down but he kept encouraging me.”

Perkins will need more than encouragement to keep making O’Neal a non-factor. It’s not that he hasn’t been very good defensively, he has, but O’Neal has been uncharacteristically bad.

“Jermaine has had some shots that he can make and he’s missed so we can’t count on him to keep missing,” Rivers said. “You just have to keep fighting him every inch on the floor.”

That Perkins can do. Smile? Not so much.

WHOSE ROLE PLAYERS WILL HAVE BIG GAMES?

It is one of the oldest maxims in the NBA: Reserves play better at home than they do on the road. In Game 3, Miami’s bench was almost the deciding factor.

Dorrell Wright, Udonis Haslem, Joel Anthony and Mario Chalmers combined for 39 points, 14 rebounds and eight assists. The Celtics bench responded with 10 points, four rebounds and one assist.

If the Heat are going to have any chance in this game, and the series, they are going to have to get production from some place other than Wade. They got it in Game 3 from their bench and if things had worked out differently in the final minute, we might be talking about a real “must-win” game Sunday.

The other concern for Rivers is what he calls the 50-50 plays. That is the loose balls, contested rebounds and hustle plays.

“We have to be better defensive team [Sunday] than we were in Game 3,” Rivers said. “They won the 50-50 game the entire game. We can’t lose that again.”

ARE THE CELTICS FINALLY COMING TOGETHER?

It certainly seems that way. The defense has been sharper, the rotation is mostly set and Garnett, Pierce and Allen are all hitting their stride at exactly the right time.

“When we’re all playing well we’re tough to beat,” Pierce said. “What better time to have it then in the playoffs?”

They’re also healthier than they’ve been in quite some time and the two things are obviously related. “We’re only as goes our health,” Rivers said. “We know that and that goes for every team.”

The Celtics got people’s attention with they won Game 2. They earned some respect with their Game 3 win. As much as they don’t want to look ahead, the specter of James and the Cleveland Cavaliers is looming large. If they take care of business Sunday they will have put those nagging regular season questions to rest, at least for a day or two.

So, is this just the beginning?

“We’ll see,” Rivers said. “That’s what I’ve been saying all year. I can’t give you the answer. I think we can, yes. I have no doubt that we can but you have to do it, but that’s something we’ll have to find out.”