There have been 12 Game 7’s since 2008 and the Celtics have played in five of them. They won three at home before losing to the Magic in 2009 and they also suffered their most bitter defeat of this era in the 2010 finals on the road against the Lakers.

Overall, the home team has won nine of those 12 games, but without Avery Bradley and with several other key players battling injuries, the Celtics can’t rely on the Garden to save them. Still, as the series shifts back to Boston, homecourt is one of the biggest reasons for optimism.

The other is their experience. Seven of Philly’s nine rotation players are 25 years or younger, and none of them have ever played in a game of this magnitude. (Of course the flipside of that is the Sixers have younger legs and healthier bodies).

“We’re going to go home. Confidence is very high,” Kevin Garnett said after their Game 6 loss in Philadelphia. “We’ve been here before. We’re very experienced. All out. Nothing less.”

Ever the realist, Rajon Rondo was unconvinced of his team’s supposed advantage.

“I can’t speak for [Philadelphia]. I’m not in their heads. There’s only a couple of us that have been in Game 7’s,” Rondo said. “This is a new series, new group of guys going head to head and it’s been back and forth the entire series. It’s going to be a tough one at home.”

So, let’s leave it to the coach for the middle ground perspective. 

“Game 7’s are what they are,” Doc Rivers said. “It’s nice to have them at home. But you’ve got to get them still. At the end of the day, you got to go play. You can’t just rely on [being] at home.”

Homecourt is important, but it’s hardly the only factor in a series that has been agonizingly tight. Throw out the Celtics’ blowout win in Game 3, and the point differential has been dead even. It will take another strong defensive effort along with a much-improved offensive performance and a handful of breaks mixed in with some unexpected contributors.

Here are six other keys if the Celtics are going to close the series out.

PLAY WITH PACE

The Game 6 numbers were brutal. The Celtics shot 33 percent and committed 17 turnovers. They had only 16 points in the paint and just 15 attempts at the rim. Their mid-range game was even worse. Forced to take contested shots in the halfcourt, the C’s took 47 jumpers from 16 feet and out and made just 13 of them.

Garnett scored 20 points but needed 20 shots to get there and 15 of his 20 attempts came on long jump shots, causing Rivers to say after the game, “Even though Kevin had points, it wasn’t really the type of points that we needed.”

The only player who was able to get inside at all was Rondo, who took seven shots at the rim, making just three. In a telling stat, he didn’t register a single assist for a shot at the basket. (He had been averaging almost six per game in the previous five contests).

“They really clogged the paint up pretty well on him,” Rivers said. “They used other guys to cut off the seams. I thought we hurt ourselves with our pace. It was basically, we walked the ball up the entire game so we didn’t get any pace. We have to get Rondo running. Yeah, we don’t want Philly to run but we need to run.”

This also falls on the defensive end. When Rondo is at his best is when the Celtics string stops together and get out in transition.

“I don’t think we were in a rhythm,” Garnett said. “At points certain players were in rhythm but as a team, collectively, no. That’s not what we hang our hat on. When we’re in a nice defensive rhythm we turn that into points and we weren’t in that type of rhythm.”

The Celtics have had two good offensive games in this series and they played fast in both of them. With so many players banged up and points at a premium, they can no longer count on winning grind-it-out games against a younger, more athletic opponent.

CAN RAY ALLEN BREAK OUT?

Credit Doug Collins with making a defensive adjustment on Allen after devoting considerable energy to keeping him under wraps throughout the series. Instead of face guarding and trailing him aggressively off his screens, Philly treated him like an afterthought, yet Allen still shot 4-for-11 and made only one of five from behind the arc.

Allen’s value throughout the series has been the simple fact that he’s Ray Allen. With all that attention being paid, lanes were opened for Rondo to drive, Garnett to post and Brandon Bass to shoot. Allen strung together two solid games at the beginning of the series, scoring 29 points, but since then he’s shooting just 36 percent and is 3-for-14 on 3-pointers. If the Sixers continue that tactic in Game 7, Allen has a chance to turn in a vintage performance, but only if his body allows it.

“They allowed Ray to get loose and he just didn’t make shots,” Rivers said. “That will be good for Ray coming into the next game now that he knows that he’s going to get shots now. Hopefully he can get his feet under him and get some rhythm.”

If not, Rivers needs to find someone else to carry those minutes.

WILL SOMEONE HAVE A P.J. BROWN MOMENT?

Once upon a time, P.J. Brown scored 10 points and grabbed six rebounds to help the Celtics win a Game 7 of the Eastern Conference semifinals. The Celtics would certainly take some unexpected offense from anywhere, but what they really need is some defensive help on the perimeter. What they need is Marquis Daniels.

The Sixers were able to pull away in the second half of Game 6 by posting up Allen and then spacing the floor and letting their ballhandlers attack the basket from the middle of the floor. Without Bradley to cool any of them off, the Sixers are simply going to isolate whomever they want and go to work.

Rivers finally pulled Allen and brought in Daniels off the bench late in the fourth quarter to see if he could replicate his defensive magic from the Atlanta series when he was able to keep Joe Johnson under control. But Daniels had seen less than six minutes of time in this series up to that point, and that put him in a tough spot. 

With Avery Bradley out and Mickael Pietrus already playing 36 minutes, the Celtics need someone else on the wing to take some minutes. Daniels may not be the best offensive option – is such an option actually exists – but if he can give them spot minutes and solid defense, it could prove to be a difference-maker.

BRANDON BASS JUST NEEDS TO BE BRANDON BASS

One game after his breakout 27-point performance, Bass had a miserable shooting night, making just 2-of-12 and going 0-for-6 from his favored midrange spot. His shots are going to be there and the Celtics need him to take them.

“Bass had 12 shots and I would say nine of them were very good looks,” Rivers said. “They just didn’t go in. Brandon had a great game [in Game 5]. I didn’t think Philly was going to change their gameplan over that. They were still going to give him shots. He’s been the guy they’ve been giving shots to this entire series.”

Bass has taken more than 10 shots in each game since the opener and before Game 6, he was shooting over 50 percent. They don’t need him to have a podium game, but they could desperately use 12-15 points and six rebounds.

TIGHTEN UP DEFENSIVELY

The biggest concern coming into the series was Philly’s transition game, which has had its moments, but hasn’t truly taken over. The Sixers are still the same high-risk, low-reward team without a true floor leader that takes far too many long-range jump shots and lacks a reliable post presence. Aside from the occasional hot stretch at the end of games, they haven’t been able to gain any separation on the scoreboard.

Consider that the Celtics shot 31 percent in the first half of Game 6 and still had a three-point lead. Their defense has been the one constant, but amid all their offensive struggles, their occasional lapses become magnified.

They switched up their pick and roll coverage for Game 3 and the results have been mixed. Again, not having Bradley to guard the ball is a drain on their defense. Despite his second-team All-Defense nod, Rondo is a defender who gets by on reputation and high-risk gambles. The Celtics have allowed far too much dribble penetration, which gets the big men out of position and opens the door for offensive rebounds and second-chance points. 

Having said that, their defense has been exceptional at times and very good for most of the series. It’s when their offense betrays them and they have to get stops that they’ve been vulnerable.

KG, PIERCE AND RONDO

You can talk about intangibles and the ghosts of Celtics past all you want, but when it’s all said and done this will come down to their three best players. Rivers refused to take any of them off the court in the second half of Game 6, which was an indictment of his thin depth as well as a nod to their importance. 

Pierce had done what he can against Andre Iguodala, scoring 88 points in the last four games. He’s lived at the free throw line, making 36 of is 40 free throws during that stretch. Of the three, he offers the most consistency.

Garnett had given them two monster games, a handful of solid performances and one clunker in Game 4. For the Celtics to win, he needs to control the boards, run the defense and take 15-20 shots with at least half of them in the paint. It’s a lot to ask of the 36-year-old Garnett, but it’s what the times demand.

Rondo needs to be Rondo. He has to push the action even when it’s not there and not give up on his offense if shots aren’t falling or he’s not getting calls. Before Game 6 he had controlled the series and lived in the paint. If there’s going to be any more run left for this era, it will fall on the player who is expected to lead the next generation.

From the time the season began right up until the start of the playoffs, the conference semifinals seemed like this team’s ceiling. The equation changed when Derrick Rose tore his ACL and the Celtics were gifted homecourt advantage.

A victory would prolong an underrated era in team history, but a loss would leave a bad taste and unmet expectations. Who knows if they have anything left beyond this, and in some ways it doesn’t really matter, because everything they’ve worked for is on the line in Game 7.