The Post Sports Live crew discusses whether this season’s playoff appearance was the Capitals’ last best chance to win the Stanley Cup. (Post Sports Live)

Adam Oates gathered his Washington Capitals one final time Wednesday at the club’s Arlington headquarters, not yet 48 hours after the season collapsed. Oates has been here for a single season, and a truncated one at that, but he knows the organization’s recent theme: potential to contend for championships, only to exit the playoffs early. So he brought up another franchise: the Boston Bruins.

For three straight seasons, Boston entered the postseason identifying itself as a Stanley Cup contender. In 2010, the Bruins built a three-games-to-none lead over Philadelphia, then a three-goal lead in Game 7 — and somehow lost their Eastern Conference semifinal series.

“Yet they haven’t changed anything,” Oates said he told his players. “They’re still the same team going on the same page. That’s why I think you’ve got to stay with it, and everybody try and keep getting better, and one day it’ll just happen. You’ll grow as an organization, and it’ll happen.”

For the Bruins, it happened in 2011; they won the Cup. The Capitals, quite famously, are still searching. They are one of only five teams to make the playoffs the past six seasons. Of those, three — Detroit, Pittsburgh and Boston — have won a championship during that span. The other, San Jose, has played in the conference finals twice. The Capitals haven’t advanced even that far, and the annual search for answers that began moments after their 5-0 loss to the Rangers in Game 7 of their first-round series Monday night continued as they met Wednesday and then scattered around the globe.

“We need to take the next step,” top-line center Nicklas Backstrom said. “I don’t really have a good answer for you — how. We think that we know the answer in the locker room. We talk about it every day, how you should play.”

The answers are the hard part. Over the past six years, the Capitals have gone into the postseason as upstarts (2008), Presidents’ Trophy winners (2010), underdogs (2012) and on-a-roll contenders (2013). But during this period — when the core has included Backstrom, two-time Hart Trophy winner Alex Ovechkin, defenseman Mike Green and forward Brooks Laich (who was injured for these playoffs) — they have won three series and lost six. So the unwavering organizational message — essentially, stay the course — seems open to questioning.

“When the same group has been together year after year after year, maybe the group’s not quite good enough,” said Ray Ferraro, who played 18 years in the NHL and now serves as an analyst for Canadian network TSN.

“It’s not like they haven’t made change there. But you look at the Capitals and Ovechkin, Backstrom and Green are the first things you think of, and I think all of them can be top-level players at their position. . . . But you’ve got to have more people around them. I don’t know, is Marcus Johansson a first-line player? Probably not, but that’s where they have him because that’s what they have.”

Looking for an explanation

The Capitals, from the top down, contended Wednesday that what they have is championship-worthy. “We’re going to win a Cup here,” Green said. Players have repeatedly endorsed Oates, who got off to a 2-8-1 start during a lockout-shortened season but never wavered. General Manager George McPhee, too, said he was pleased with his hire — and, really, the entire roster. It is McPhee who has assembled the teams that have excelled in the regular season but fallen out of the playoffs, and he said he has occasionally tried to find a thread that might explain those results.

“Sometimes, you can look at it and say, ‘We just weren’t good enough in this area,’” he said, noting a 2011 team that was too thin defensively. “And there are other years you say, ‘You know what? We were a good team, we played well, we didn’t get the bounce. . . . This year, this was a good team.”

So how to explain the loss to the Rangers, who the Capitals led both two-games-to-none and three-games-to-two? McPhee went through something of an instant analysis: Capitals goalie Braden Holtby held his own again New York’s otherworldly Henrik Lundqvist until Game 7; the Capitals’ five-on-five play continued to be excellent as Oates’s system took hold; the Capitals killed penalties well.

“We didn’t get many power plays in the series,” McPhee said. “I don’t know why. We had to kill too many penalties. I don’t know why.

“I didn’t think that part of the game, from a league standpoint, was all that good. I didn’t like the refereeing, but if you complain about it during the series, you’re accused of trying to gain an edge, and if you complain about it after a series is over, then you’re whining and it’s sour grapes.”

McPhee is not alone in the organization in wondering about the lopsided officiating — which led to 16 power plays for Washington and 28 for New York. Ovechkin told reporters that the league “wanted Game 7,” and a team source said Wednesday that the officiating had gotten into the heads of some players after New York had five power plays and the Capitals none in Game 6, a 1-0 Rangers win.

But that doesn’t mean players aren’t trying to decipher how these playoff exits keep happening. Monday’s loss to the Rangers was the fifth Game 7 loss in the past six years, the third at home. Three times — 2009 against Pittsburgh, 2010 against Montreal and this year against the Rangers — they led the series either 2-0 or 3-1. Some players suggested the team must figure out a way to develop what forward Troy Brouwer called “a killer instinct.”

“The common thread for me is that we take every series to seven games,” forward Eric Fehr said. “We’ve had leads in just about every series we’ve played in, and we haven’t been able to close it out. I think that’s the one thing we need to learn is that Game 6 needs to be our new Game 7.”

‘Sense of pride’

When such failures define a team, there is a natural tendency to look at the leaders. Ovechkin is the captain, yet he was absent from the final team meeting because he had already left to play for Russia in the World Championship. Oates said Ovechkin texted him repeatedly until 2 a.m. Tuesday, the hours after the loss. “He was very upset,” Oates said. They met later Tuesday. The coach said he had no issues with leadership from Ovechkin or others. Players, too, defended the team’s dressing room culture.

“There’s a tremendous sense of pride in the guys that have been here, to when we finished dead last, finished 15th, and brought it to the Stanley Cup contender that we believe we are today,” Laich said. “We feel we have excellent leadership — excellent leadership. That is not a point on our team that we are worried about or concerned about or has anything to do with loss of hockey games.”

Yet in the spring, the losses still come. That pattern can make people wonder if tweaks are in order. Internally, there is little of that discussion.

“I’m a first-year coach, and when my boss asks me, I’m going to tell him you can’t push the panic button,” Oates said. “Now, that’s my opinion. It’s up to him and [owner] Ted [Leonsis] and all that to decide on that. . . .

“You know, Nick Backstrom had me for one year. He’s going to be better next year, I feel. These guys haven’t reached their limits. And I think they started to feel that too. ‘Oh, we’re improving. We’re not just surviving, we’re improving.’

“Last year the Caps, to me, survived. They brought in [former coach Dale Hunter], it was survival mode, ‘Oh, can we get there? Oh my God.’ Then a little bit of Cinderella story in the playoffs, right? I don’t feel that way. We expected to win. They didn’t expect to win last year.”

Yet they didn’t win this year, either. But from the first few hours of the offseason, it appears that this team — at least the bones and heart — will return in the fall to try another time.

“You don’t get players like this,” McPhee said. “Where do you get another Ovechkin? Nick Backstrom’s a heck of a player. Mike Green’s a heck of a player. [Defenseman John] Carlson’s on his way up. We’ve got a lot of good young players, and keep going to war with them.”

Mike Wise contributed to this report.