The signs all over the Capitals’ training complex on Thursday said: “Canine Training Day.” For the Caps, a.k.a. the choking dogs of hockey, you can’t make this stuff up.

In this case, it was the Department of Homeland Security that had brought its K-9 corps to Kettler Capitals Iceplex in Arlington for instruction. But, before next year’s NHL playoffs begin, somebody better teach the Caps how to bite.

Will it be cheerful ringmaster Ted Leonsis, author of “The Business of Happiness,” who adores his players, believes in his execs and hates to fire people he respects. If he was just a bit too proud of what he’d built, who’d tell him? And would he listen?

Will it be General Manager George McPhee, who foresees no coaching change and insists, “I don’t think anything is missing. . . . I don’t see major changes. It’s a good team. . . . We are all here to win a Cup. But it’ll make it that much better when we do win it after having to fight for it all these years.”

Will it be adorable Coach Bruce “Gabby” Boudreau? On Thursday, he said, “You never want to get swept. But any of these games could have gone either way. With the salary cap, we have parity. . . . It’s going to come down to breaks, and I don’t think we got as many as we should have.”

At times like this, when a No. 1 seed gets swept by a No. 5 seed, you line up the firing squad or you line up the excuses. For the second straight year, the Caps went with the excuses. McPhee and Boudreau ran through a long list of Caps injuries, especially to four of their best puck-carrying defensemen. All teams have injuries. The Lightning was probably just as hamstrung. But the Caps hate to be cruel. What others might call whining, they see as mitigating circumstances.

McPhee respects his players’ pain. His face darkens as he describes Mike Knuble playing with a shattered thumb that required four pins and pain-killing shots just so he could take the ice. He knows which man can’t open his own car door after a game, which may never play again and which could hardly get off the ice unaided after one game.

Attuned to such sacrifice and 100-hour coaching weeks, McPhee transmits that appreciation to Leonsis, a man defined by loyalties. If you bleed for them, they find it mighty hard to slit your throat. And that’s wrong?

In a sense, the Caps are trapped by their own culture of decency, self-regard and optimism. They want to give everybody a second, and sometimes a fourth chance, even the coach. They don’t want to act in haste and repent at leisure, even if it means soft players aren’t traded and get to repeat their spring failures. They don’t want to blow up what they’ve built because they believe in sound foundations. But the Caps also flatter themselves that what they have created is a notch better than it actually is. And the Caps hate, hate, hate to admit any evaluation is wrong, until it’s so obvious they can’t deny it.

Good intentions, good results, then playoff mortification, year after year, followed by the same mantra: There’s nothing wrong. We were just unlucky or injured. Next year: our turn. Keep the sellouts coming.

Judging by every exit-day comment, here we go again. You want to congratulate the Caps for character, interrogate them for their blind spots and kick them for their results. What team reacts to such devastating defeats with equanimity, common sense and a huge sigh of acceptance at life’s unfairness? How estimable. But it drives you nuts.

Last year, in my post-mortem column, I suggested the Caps were built for the regular season but might keep doing poorly in the postseason because they didn’t play a gritty, ugly-goal, net-crashing, shot-blocking NHL playoff style. The Caps didn’t agree. Nothing was wrong, just a few tweaks. Then, nine months later, with plenty of real hockey experts aboard, they basically made exactly that style switch. By waiting, by trying to be fair to everybody and analyze everything, they probably paid a big price.

On Thursday, my car’s GPS said it could get me to Kettler in Arlington 10 minutes faster than my old route. So, I changed my lifetime-long driving patterns. I saw places I’d never been in 50 years. My ingrained habits were conflicted by my new and better system. When The Voice said, “You have arrived at your destination,” I said, “The hell I have.” Yet I was there at the practice rink, but from a different direction. I got there faster, but my disoriented driving almost got me squashed by a couple of 18-wheelers.

Think of me following the GPS as the Caps.

They changed their “system” in January. They obeyed The Voice: More defense, less attack, more dumping and chasing, more bodies on the doorstep, less goals with a bow tied around them. It worked in the regular season. Then came the playoffs with everything at quicker speeds, with more disorientation, more 18-wheelers and more temptation to fall back on ingrained lifelong hockey habits.

The result: the Caps were a talented team with a half-formed identity and key players who don’t fit the new paradigm. With higher stakes and a faster pace, the Caps came apart. They looked lost. Boudreau seemed stunned and unable to adapt. Mid-series Caps quotes sounded like they came from an already beaten team. After Game 3, the brave Knuble said he was “flabbergasted.”

“A lot of people are in disbelief,” Karl Alzner said. “We didn’t have an answer for a lot they threw at us.”

The Caps brass doesn’t yet acknowledge how decisively Tampa Bay beat them. Eventually they may. But they still probably won’t fire Boudreau. McPhee truly reveres him — strictly as a coach, personality aside. And Leonsis knows that McPhee built the roster that fills his arena every game with fans who wear actual Caps jerseys, the expensive kind, not those free giveaways. Ted, the delegator, won’t undermine GMGM.

So don’t expect much change. The Caps’ decency and patience have produced crowd-pleasing, winning teams. Damned if they aren’t going to try to win a Stanley Cup the same way. No matter how long it takes. Even if it kills ’em. And us.