The Capitals have killed 13 consecutive penalties and are much improved since the beginning of the season. (Toni L. Sandys/THE WASHINGTON POST)

The Washington Capitals scored five goals in routing the Montreal Canadiens on Saturday night, but the offensive outburst might not have mattered if it wasn’t for a show of strength from the penalty-kill unit.

Up by two goals early at Bell Centre, the Capitals were confronted by multiple Montreal power plays that could have altered the course of the game. But Washington’s penalty kill neutralized the Canadiens’ man advantage, which entered the game tied for fourth best in the league.

While Washington’s penalty kill has been one of its biggest liabilities for much of the season, and still ranks among the worst in the NHL, the unit has shown marked improvement in recent weeks. Its perfect 5-for-5 outing against the Canadiens was simply the latest example.

Washington has thwarted 13 consecutive power plays and over the past 21 games the penalty kill is operating at an 81.4 percent success rate (48 for 59). The unit is still ranked third worst in the NHL (77.8 percent), but that’s largely a reflection of the rough initial adjustment to the coaching staff’s overhauled approach to killing penalties at the start of the season.

“We just wanted to rebuild the whole thing right from the get-go,” said Assistant Coach Tim Hunter, who directs the penalty kill. “There’s just been a whole revelation of how to kill penalties for our guys. They went from being completely aggressive to being somewhat passive and now we’re edging toward being a little more aggressive in certain areas.”

As the Capitals likely head into the playoffs, the Post Sports Live crew debates whether the Capitals are one of the top three teams in the Eastern Conference. (Post Sports Live)

Coach Adam Oates, Hunter and the rest of the coaching staff put an end to the mantra of all-out aggression and shot-blocking at any cost that prevailed during Dale Hunter’s tenure as coach last season.

They want penalty killers standing up, focused on correct positioning in order to anticipate and guard against the next play — not diving in front of shots. Capitals penalty killers are still encouraged to block shots, but without dropping to the ice because the moment a player leaves his feet it’s more difficult, if not impossible, to recover and defend against the next play.

Adjusting to the more passive approach was difficult, largely because it was a departure from everything the penalty killers had been taught.

“When they tell you not to block a shot it’s kind of like, ‘Well, then, what do I do?’” Karl Alzner said. “Normally you go out there and you think, ‘My job is to go out there, block a shot and get it down.’ Now it’s more trying to think a little bit, think what the PP’s going to do and be ready for it — we’re trying to be a smarter hockey team.”

The penalty killers weren’t the only ones who needed to adapt to the new style. Goaltender Braden Holtby was used to having clean sight lines over teammates as they blocked shots; he could more easily see the trajectory of the puck and potential deflections. Now he has to contend with many more screens.

“It was tough. At the start of the year I was wondering why I was never seeing pucks. There was constantly something in the way,” Holtby said. “We changed a bit of my game to get lower on things. It exposes the top half of the net a bit more but it gives me a better chance to see around and it’s worked a lot more.”

The transition was ugly at first. Penalty killers trying to reprogram themselves had to fight their shot-blocking instincts and were often caught out of position.

“There was a lot of teaching going on,” Hunter explained. “When you go out and you’re on your feet, now what do you do with your stick?. . . As a forward, do something with your stick that’s useful. Put it in the right place. Deter them or try to stall them in what they want to do.”

Washington’s abundance of penalties early in the season didn’t help the situation either, and exposed the unit before it could establish familiarity with its new shorthanded rules. Of the 34 power-play goals the Capitals have allowed this season, 15 came during the dreadful 2-8-1 start, when the penalty kill went 36 for 51 (70.6 percent).

Improvement truly started in mid-March when the coaching staff, concerned the players were growing a little too reactive, decided to add in some selective aggressiveness. Like everything else, though, it’s about being smart and pressuring at key moments. It’s up to the penalty killers to know when to try to force an opposing power play into rushed decisions or when they should hang back, focus on their positioning and eliminate as many threats as possible.

“It comes down to the timing of it,” Matt Hendricks said. “Everyone is starting to work well together, and I think before when we would have those trigger moments — when a guy bobbles the puck or could slow a team down in the neutral zone — only one guy would go. We’re getting more comfortable with the coaches’ system and knowing when we all need to go or stay has made the difference in the last month or so.”