Bruce Boudreau’s below-average playoff record of 17-20 (.459) keeps being used as evidence for his firing as the Washington Capitals’ coach, which makes perfect sense when you learn Scotty Bowman started 28-30 (.483), Al Arbour began 12-15 (.444) and Glen Sather was a lousy 12-25 (.324) to begin in Edmonton.

Why their respective teams hung on to those bums made no sense, putting aside the combined 17 Stanley Cups they won.

The Capitals’ problem is not the coach. That’s not why they got swept in the second round against an, on paper, underwhelming Tampa Bay club.

The problem is the nucleus. Alex Ovechkin and his three co-stars are not ready yet. Some, such as Alexander Semin, may never be.

In hockey, the term “boys” is used affectionately, as in, “Ovie and the boys.” But Ovechkin, Semin, Mike Green and Nicklas Backstrom are not boys anymore. They have been to a few rodeos, and they keep getting bucked off.

The Capitals are becoming the Dallas Mavericks of the NHL. They have become that team with the heavenly regular season and the hellish postseason.

They have all the talent. They appear to make the right tweaks each offseason and trading deadline to get better. They have national media anointing them champions before either the regular season or the playoffs. And four years after the Capitals began to show real promise in the Great Eight era, they have yet to sniff an Eastern Conference finals — never mind hoisting the damn grail.

Why? Their best young players have yet to grow up and mature into great young players, ready to play their best at the time of year that matters most.

They are led by a Russian who, despite being among the most exciting players in the game’s history, hasn’t won anything of real team value.

No more Sidney Crosby comparisons, please. Crosby has played in two Stanley Cup finals and won one; Ovie has yet to advance past the second round of the playoffs.

Fire Boudreau? Really? Go ahead. Bring in a hardcore retread or the next young rising star among NHL taskmasters. It won’t matter.

This team doesn’t need a coach transplant; it needs a heart transplant for many of its young players.

Yes, you, Alexander Semin. How do you say “prima donna” in Russian? You refuse to talk after losses, even to your countrymen who wait patiently to be stood up. Until you learn to be accountable, you suffer from the same malaise your team did against the Lightning.

You too, Nicklas Backstrom. You can’t be on the ice for 27 minutes and not take a shot as you did in Game 3; that’s not unselfish, that’s unaware of your responsibility as a scorer on this team.

Mike Green, you get a pass this postseason because you played remarkably well against the Rangers after coming back from a concussion in February, including taking a slap shot to the head in Game 5 that was about as selfless an act to stop the puck as any this postseason.

But Green is a part of a larger narrative that began in 2008. This group is becoming more known for its playoff losses than all the good things it did to change the culture of the organization.

These Caps have lost three Game 7s on their home ice. Yes, they forced Game 7 in shows of grit and perseverance against the Flyers in 2008 and the Penguins in 2009. Indeed, they overcame a three-games-to-one deficit to beat the Rangers two years ago.

But just as they seemed to be ascending to the next level, they stumbled badly. Just as they learned the thing all championship teams need to learn, to build upon success — burying the Rangers in five games in the first round to earn a well-deserved rest — they capitulated in four games to the Lightning.

The team that appeared to learn how to handle prosperity two weeks ago suddenly couldn’t even deal with adversity any more.

And that’s where owner Ted Leonsis and General Manager George McPhee have to look at themselves.

This had to hurt worse for the owner and the general manager than the past three years. See, while the rivalry between the Lightning and Caps will never reach Pittsburgh-like decibel levels, in the owner’s mind, this series was seminal.

When he used to irresponsibly purchase other team’s stars, Leonsis watched Martin St. Louis and Vincent Lecavalier skate past the Caps in 2003, winning the first-round series in six games after Washington was up 2-0. That series made him start anew; it’s why he blew up the team, lost gobs of games and fans, why he was able to draft Ovechkin No. 1. Eight years later, a 35-year-old St. Louis rocketed home the clinching goal in Game 4, and Lecavalier was brilliant all series.

Eight years after the Jaromir Jagr experiment failed in Washington, Tampa Bay retooled around the same aging stars and swept the newest edition. That’s not progress. That’s back to square one.

The last four games happened to the Capitals, irrespective of the fact that they had ample opportunity to win three of them. They were victims of their own malaise at the most crucial junctures of the third period, almost spectators to their own demise as the Lightning looked impossibly fresher and fitter.

Now the four celebrated young stars have to take a hard look at whether they want to become part of this franchise’s hard-luck history or genuinely change it.

Curses in sports are ridiculous, applying only to zealous fans that need to come up with reasons for their heartbreak. But different eras can be individually predisposed to losing big games. If a core group of players happens to fight the puck and think too much and not trust its instincts and experience when a game is close — in other words, become mentally weak as a team — that has carryover. That can become contagious in pressurized moments.

And if that is part of the bad energy in that locker room, it needs to be eradicated by going cubicle to cubicle and holding the players accountable, even the captain. Not the coach.

The Caps’ flameout is an indictment on the Ovechkin era, not the Boudreau era.