Game 7 isn’t for the faint of heart. It’s a tightrope walk on a straight razor. Those who stumble will suffer a 500-foot reputational drop. Awaiting the sure-footed on the other side, though? Glory, hosannas and renewed hope of hoisting the Larry O'Brien Championship Trophy.

One game, winner take all; survive and advance, lose and go home. It’s the nature of competition, distilled: winning or misery.

The Boston Celtics and Philadelphia 76ers have the chance to seize one and avoid the other, with berths in the NBA’s final four hanging in the balance. Here are some big questions to mull over as we wait for them to take their first steps out onto that high wire:

Philadelphia 76ers at Boston Celtics (3:30 p.m. ET, ABC)

1. Does Philly change its starting lineup, too?

Joe Mazzulla’s decision to shuffle the deck for Game 6, supersizing the starting lineup by replacing guard Derrick White with center Robert Williams III, paid massive dividends for Boston. Williams’ breakthrough last season helped fuel the Celtics’ run to the NBA Finals, but an up-and-down return from offseason knee surgery — combined with excellent play by White as part of a smaller look that juiced up Boston’s shooting and playmaking — has at times left Timelord relegated to the outskirts of the Celtics’ rotation. On Thursday, though, he made his presence felt early and often.

It wasn’t just the 10 points and nine rebounds in 28 minutes, although having Williams in the mix to bang on the offensive glass and soar above the defense for lobs certainly didn’t hurt. It was more about how stationing him alongside Al Horford allowed Boston to choke off an offense that had gotten cooking in the Sixers’ Game 5 win:

With Williams sagging off P.J. Tucker to help clog the paint and take away the Sixers’ bread-and-butter looks out of the Joel Embiid-James Harden pick-and-roll, Philly scored just 32 points in the 19 minutes that Williams and Horford played together, according to NBA.com’s lineup data, shooting 10-for-23 inside the arc and 3-for-11 outside it. The Sixers scored a woeful 80 points per 100 possessions in those 19 minutes — 20,000 leagues below their top-three full-season mark, and nowhere near the level of productivity they’d mustered in their three wins in this series.

“He’s in the paint, so it’s like the paint is crowded,” 76ers guard Tyrese Maxey told reporters after the game. “That was new for us. But I mean, we knew they were going to do that, we knew they were going to try it. I think that we’ll be better next game.”

Things did pick up a bit, though, when Doc Rivers moved Tucker to the bench in favor of combo guard De’Anthony Melton or floor-spacing forward Georges Niang. Putting a more willing and potentially more threatening shooter in the corner helped decongest the Sixers’ half-court offense; in 17 minutes with either Melton or Niang sharing the floor with Embiid, Harden, Maxey and Tobias Harris, Philly outscored Boston by 7 points.

Those results match up with regular-season production that saw Philly score like gangbusters with both the starters-plus-Melton and starters-plus-Niang lineups on the floor — albeit in small samples, likely owing to how much Rivers trusts Tucker defensively and values his toughness, communication and leadership. At this point, though, a small sample can change everything, whether that’s a string of possessions in the middle of the third, the final 5:57 of the fourth … or the tone-setting opening minutes of a winner-take-all war.

"We'll put [Tucker] on the floor more when there's one big, we'll put Georges or Melton on the floor when there's two," Rivers said after the game.

Will he do it right from the start? If so, can Niang — widely viewed as a defensive liability, but acquitting himself surprisingly well on that end in this series — continue to hold up well enough under questioning on that end in a Game 7 to give his shooting a chance to loosen up Boston’s defense and tilt the math back in Philly’s favor? Will Melton can the open looks he’ll get when the C’s help off him, as he did in going a combined 9-for-13 from deep in Games 1 and 3, or come up empty, as he did in missing all eight triples he tried in the other four games (including three backbreakers late in the fourth of Game 6)? Or will Doc trust Tucker to make his 3s — like Grant Williams did for Boston in Game 7 of last year’s second round — and make enough of an impact elsewhere to neutralize Timelord’s looming menace?

2. Will make-or-miss make or break Boston?

It’s not a particularly revelatory take to say that a team’s more likely to win when it shoots well than when it doesn’t, but that’s been true to the extreme for this Boston bunch. When the Celts have shot 40% or better as a team this season, they’re 35-2; when they shoot under 40%, they’re 29-28.

When the Celtics were 4-for-13 in the paint in the first quarter of Game 6 and with Jayson Tatum continuing his five-game trend of not being able to hit the broad side of a barn in the early going, getting six combined long balls from White, Marcus Smart and Malcolm Brogdon still staked them to an advantage. Drive-and-kick, catch-and-shoot triples by Jaylen Brown, Smart and White helped push the lead to 16 midway through the second. And when Philly had seized control midway through the fourth, it was Tatum’s closing barrage — four 3s in the final 4:14 — that left the Sixers staring up at the ceiling, wondering what had hit them:

This is the team that Boston’s built to be: a high-volume 3-point shooting team, and thus a high-variance one. It gives the C’s a chance to put up crooked numbers even against an opponent featuring an interior menace who shuts down the lane — they’re averaging 13.4 fewer points in the paint per game in this series than they did against Atlanta in Round 1, and shooting just 54.1% at the rim when Embiid’s contesting, according to Second Spectrum — and, at this stage of the season, it has to remain their calling card even if things get tight.

We’ve seen shoot-first teams go ice-cold from the perimeter in the crucible of a Game 7. (The bearded guy wearing No. 1 for the Sixers was on one of them.) If Boston opens up clanging Sunday, the fans in the stands at TD Garden will likely find themselves begging for Tatum, Brown (whom nobody on Philadelphia’s roster can stay in front of) and the rest of the Celtics’ ball-handlers to just put their head down, get into the paint and either challenge Embiid or try to get to the free-throw line. It might be more likely, though, that the team Brad Stevens has built and the players Mazzulla has coached will keep firing, trusting the process (cough) and believing that the shots they’ve knocked down all season will fall. When the money’s on the table, you’ve got to dance with who brung you, and hope that you’ll wind up on top when the music stops.

3. Will Philly’s stars shrink or shine?

Harden has had arguably the two greatest postseason games of his career in this series. (You could make a case for his 38-10-9 performance against the Warriors in the 2015 Western Conference finals … but that one ended with him passing out of a fast break down by one in the closing seconds with a chance to win it before fumbling the ball as time expired.) He’s also had three of his worst, going a combined 9-for-44 from the field and 2-for-19 from 3-point range in the Sixers’ losses in Games 2, 3 and 6.

Philly desperately needs him to strike some kind of equilibrium — as he did in a brilliant table-setting Game 5, which coincidentally happened to be Embiid and Maxey’s best offensive performances of the series — to have a shot at winning in Boston for the third time in this series. He doesn’t have to be the all-encompassing inferno of Games 1 and 4, but he can’t be the feckless foul-seeker of Game 6, diving headlong into crowds, stumbling to the floor, begging for bailout calls and griping when he doesn’t get them. Sixers fans can only hope that Harden doesn’t carry the woe-is-me frustration that bubbled over Thursday …

… into a Sunday that presents another opportunity not only to send Philadelphia to the conference finals for the first time in 22 years, but also for one of the greatest offensive players of all time to radically reshape his postseason legacy.

If Harden can manage to shake off a bad Game 6 and do what he’s done all season — sacrifice, facilitate, and star in a more complementary role — then it’ll be up to the newly minted MVP to do what he’s done all season: prove nigh-on unguardable no matter the scheme or opponent, and bend the game to his considerable will.

With 3:30 to go in Game 6, Embiid had 26 points on 9-for-19 shooting. He’d finish with … 26 points on 9-for-19 shooting. In a related story, the Sixers scored 1 point down the stretch before Rivers waved the white flag and pulled his starters.

“We had a lot of wide-open shots, we didn't make them. We stopped moving the ball. And I don't think I touched the ball the last four minutes of the game," Embiid told reporters after the game. "Missed a lot of good looks. I didn't touch the ball at all."

That, obviously, is something Boston is working very hard to make happen. Everywhere Embiid went in that late stretch, Horford followed, typically joined by at least one teammate pinching in to create traffic and try to dissuade Philly from working the ball to the big fella. But it is also, obviously, something that the Sixers cannot allow to happen.

You have to make them hit your fastball, and for Philadelphia, that’s putting the ball in Embiid’s hands — at the nail, on the block, at the top of the key, wherever the hell he happens to be — and giving him the chance to decide your fate. One year ago, Philadelphia’s season ended with one of its stars disappearing and lamenting how the ball “never got back” to him. Things have to be different Sunday; if they’re not, the result may well be exactly the same.