TORONTO — How does this happen?

How does a team that wins 51 regular-season games crater like this? How does an elite defensive team that considered its collective back against the wall crumble, and surrender 92 points in three quarters? How does a team that claims four All-Star-caliber players fizzle like this?

How does a team white-flag a playoff game with almost 9 minutes to play?

Players? Coach? Cohesion?

The entire point of the first 82 games is winning 16 more. The Sixers had won six of eight, and held a two-games-to-one lead in the Eastern Conference semifinal against the Raptors. Now, on the cusp of accomplishment, two lifeless losses. A late-game collapse in Game 4 in Philadelphia. A second-quarter surrender Tuesday night in Toronto en route to a 125-89 loss.

Now, a 3-2 deficit in the series, which returns to Philadelphia on Thursday night. Wear Raptors black if you come. Feels like it’s going to be a funeral. A bitter end to this season, and, maybe, to Brett Brown’s bizarre tenure as head coach. Brown was twice warned by managing partner Josh Harris that the Sixers needed to advance beyond the second round, where they lost last season.

Brown predicted great energy from his team.

Joel Embiid of the Sixers argues with an official during the 1st half of their NBA Eastern Conference semifinal game at the Scotiabank Arena in Toronto on May 7, 2019.
CHARLES FOX / Staff Photographer
Joel Embiid of the Sixers argues with an official during the 1st half of their NBA Eastern Conference semifinal game at the Scotiabank Arena in Toronto on May 7, 2019.

“It went away quicker than I had hoped,” Brown admitted afterward.

His crown jewel disagreed.

“Us not fighting? I don’t think that’s the right word,” said Joel Embiid.

That spirit dissipated in direct proportion to Embiid’s effectiveness. He is the centerpiece of the six-year Process, but was bedridden and feverish for the third day in a row. He said he felt no better than he did in Game 4, and, if possible, he played worse. In 31 toothless minutes, Embiid scored 13 points on 5-of-10 shooting, just six rebounds and committed eight turnovers. He left the game with 9 minutes, 5 seconds to play, his team trailing by 28.

But before he left, he told hip-hop star and Raptors mascot Drake he’d see him again soon, because Embiid planned to force a Game 7 on Sunday. How? Play better.

“I know I’ve got to a better job for us to win. I’ve got to do the little things,” said Embiid, who averaged 24.8 points in the first round against the Nets. Against Marc Gasol and the Raptors, he’s averaged 17.0, and has been held to 16 points or fewer in four of the five games. He dropped 33 in a Game 3 win.

“When I don’t score the ball, I’ve got to show up. Setting screens. I’ve got to do a better job rebounding the ball. I’ve got to do more,” Embiid said. “I’ve got to go back to Game 3.”

Joel Embiid, right, of the Sixers is fouled by Marc Gasol of the Raptors during the 1st half of their NBA Eastern Conference semifinal game at the Scotiabank Arena in Toronto on May 7, 2019.
CHARLES FOX / Staff Photographer
Joel Embiid, right, of the Sixers is fouled by Marc Gasol of the Raptors during the 1st half of their NBA Eastern Conference semifinal game at the Scotiabank Arena in Toronto on May 7, 2019.

He wasn’t spiking fevers in Game 3. Brown lauded Embiid’s willingness to play sick, and said that criticisms of Embiid’s play have been “grossly unfair.”

But everything runs through Embiid, if you’ll pardon that pun on his lack of intestinal fortitude. And herein lies the cohesion issue. Embiid at missed the Game 4 film session and shootaround Sunday, missed practice in Camden on Monday, and missed the pregame film session and shootaround Tuesday. Nothing ran smoothly either game.

“I think I’m a pretty smart dude, to figure out what type of adjustments” the Sixers will make, he said. “Obviously, you need repetitions.”

“I wish he was at practice. I wish he was in film sessions,” Brown said, a bit exasperated. “But he’s sick.”

Enfeebled, Embiid was unable to guard nimble forward Pascal Siakam, a matchup that was the key adjustment in the three previous games. Tobias Harris drew the assignment. Siakam led the Raptors with 15 points in the first half and finished with 25.

He was one of four Raptors in double figures at halftime. That included backup center Serge Ibaka, who abused Embiid twice and had 10 points and finished plus-27 in 22 minutes.

Kawhi Leonard had 21, and he’d averaged 38 in the first four games, but the Raptors didn’t need his volume. Besides, quality trumped quantity. A last-minute dunk to end the second quarter sucked the will from the Sixers’ souls. Then he pounded one past Embiid’s head near the end of the third.

Despite their warts, the Sixers seemed to have divined a means by which to overcome their deficiencies, before losing Games 4 and 5. Gun-shy point guard Ben Simmons, who won’t take a shot beyond arm’s reach of the basket, shot five times Tuesday, and he turned the ball over five times in 25 minutes.

They looked overmatched and, worse, uninterested. Which brings us to Brown.

How much of this lies at his feet?

Can he be expected to coach around Embiid’s delicate constitution? Can he be asked to win with a point guard who’s afraid of depths? Can he be expected to make instant adjustments with a rotation constructed at the trade deadline and, because Embiid’s issues, has played just 20 games together?

Can any coach?

Or maybe the team’s pedigree just isn’t as advertised.

Embiid wants to be an MVP, but MVPs play well when they’re sick and they dominate when they’re not. Simmons was an All-Star this season and Rookie of the Year last, but basketball is about scoring. He can’t. All that talk about Harris being an All-Star-caliber player when the Sixers traded for him near the deadline in February now seems overblown.

Jimmy “Playing for the Max” Butler, who will be a free-agent gem this summer, showed up. He scored 22 points. At times, he was the only Sixer at the party.

In the locker room, with a country music song playing softly at his locker, Butler comforted a teammate: “It’s not the end of the world.”

He probably wondered how this happened, too.

And whether he wants to stay.