These are not the Caps that were swept out of the playoffs last season, or the Caps that struggled to qualify this season, or even the Caps that eliminated Boston in the first round of the playoffs. The interesting — even amazing — aspect about the Caps team that won Game 6 Wednesday night, 2-1, over the Rangers is that they are still evolving.

If they advance to the Eastern Conference finals against New Jersey, who knows what we might see? Will Braden Holtby actually stand on his head? Might they win a game by as many as two goals, or fewer than one? Sure, it sounds impossible, but if anyone can achieve it, it’s these Caps.

They’re changing and learning and growing and doing it faster than anything we’ve seen since the “ABC Afterschool Special” went off the air. They’ve changed coaches, changed systems, changed entire approaches to the game. They’ve gone from a finesse offensive team to a grinding defensive team. They’ve turned a third-string goalie into a first-string goalie (unless he’s a chocoholic, Holtby’s not going back to Hershey, Pa.).

And they might not be done yet. They might still have a few surprises in store. Before the playoffs began, much of Washington had various expectations of the Capitals, but few could have foreseen these two competitive first-round series.

“We put ourselves in that position,” Matt Hendricks said. “We weren’t satisfied [with the regular season] but we made the playoffs. As we win and lose, our coaches do a great job of showing us film and pointing things out. Our confidence is building.”

That wasn’t something you used to hear from the Capitals in April or in May, if they were still talking in May. Adversity was not the secret ingredient that changed their recipe for success from mild to spicy. To paraphrase John Churton Collins, “In prosperity, our friends know us; in adversity, we know the Caps.” (I think Collins played with Toe Blake back in the day.)

Wednesday night’s victory was just the latest example. Alex Ovechkin didn’t have a shot on goal Monday night in Game 5 at Madison Square Garden — one attempt was blocked, one missed — but less than two minutes into Game 6, he scored a perfectly staged power-play goal over Henrik Lundqvist’s left shoulder.

It was just the right response to those who thought this series ended with 7.6 seconds left in regulation Monday night, when Brad Richards’s power-play goal found a way to — surprise! — tie the score and — double surprise! — force overtime before the Rangers won on a second power-play goal.

In past years, that would indeed have been the end of the series, and the season. This year, the Caps laugh in the face of adversity, and howl in the face of overtime. They’ve had to — six of their 13 postseason games have gone long. But they are 4-0 in games following overtime losses.

“We’re resilient,” Karl Alzner said. “We have that thick skin now.”

They’ve needed it, because these games have been decided by the thinnest of margins. All seven games in the Boston series were decided by one goal, an NHL first. This series also has been ridiculously close — only Game 1, a 3-1 “blowout” by the Rangers — was decided by more than one goal. By comparison, the Devils won the other Eastern Conference semifinal in five games by an 18-11 margin.

The Caps nearly won Wednesday by an incredible 2-0, but Marian Gaborik bounced a shot off John Carlson’s back and past Holtby with less than a minute remaining, ruining the rookie’s chance at his first shutout of the playoffs. Holtby doesn’t behave like a rookie, on or off the ice. After Monday night’s tying and winning goals, another goalie might have been shaky. Instead, he was icier than ever, stopping 30 shots before the one that got away.

“This was a great team effort,” Hendricks said. “But the number-one performance was Holtby in net.”

Here comes Game 7. Who knows how it will end? By a margin of one goal, almost certainly. Overtime seems likely. Beyond that, expect the unexpected. The Capitals are on the brink of who knows what, and that seems to bother them not one bit.

“These are the games you live to play,” Hendricks said. “When you achieve it, it’s a great feeling.”

For Tracee Hamilton’s previous columns, go to washingtonpost.­­