On the morning of Dec. 13, Bruce Boudreau arrived at the Washington Capitals’ Arlington training facility as he would any morning during the season, just after 7. In the restless hours immediately preceding, Boudreau’s club had endured the most ignominious defeat of his three-year tenure as coach: a 7-0 humiliation by the New York Rangers, the team’s sixth loss in a row. In the hours ahead, nothing short of a sea change awaited the organization. “We had to do something,” Boudreau said.

When Boudreau took over the Capitals in November 2007, he helped transform a gifted but moribund roster into one of the most entertaining teams in the NHL, a goal-scoring machine that overwhelmed opponents with talent, skill and a wide-open, risk-taking style. But that Monday morning, when Boudreau sat down with his boss, General Manager George McPhee, both men knew another transformation was necessary. Capitals coaches and officials huddled. As the players trickled in for a practice session the next day. tension filled the building.

“I didn’t know if George was going to come down and scream at us,” veteran forward Mike Knuble said. “There was something that was going to happen that day. You kind of come in, waiting to see.”

No one lost his job that morning. Instead, Boudreau and McPhee decided to replace the team’s trademark — offense — with defense. The risks were significant. The Capitals entered the season with one goal: win the Stanley Cup. Could a team, in the middle of the season, fundamentally alter both its physical style and its mental approach and emerge in better position?

“It was a dramatic change,” McPhee said late last month. “And changing systems in the middle of the season is dangerous, because if it doesn’t work, you have players who are confused. Your system of play has to become ingrained. It has to become second nature. You can’t go on the ice thinking about a system because then the game’s going to be going by you.”

As the Capitals open the playoffs Wednesday night against the same Rangers who instigated the change, they say their new system is ingrained, and their goal of winning the Stanley Cup appears much more achievable than it did that distressing Monday morning last December. The team that posted the best record and scored the most goals in the NHL a year ago averaged more than a goal per game fewer during this regular season. Its most talented stars, led by two-time league MVP Alex Ovechkin, endured what appear statistically to be among the worst seasons of their careers.

The flip side, though, shows that what Boudreau and McPhee set out to accomplish in the middle of December worked: Just three teams allowed fewer goals than the Capitals. And no team in the Eastern Conference, from that point on, posted a better record. Washington, playing a different style, is again the top seed in the East.

“They still have that talent,” said Eric Staal of the Carolina Hurricanes, who played the Capitals six times this season. “Now, they’re just playing a smarter game. I think they’re definitely a tougher team to play against now than they have been in the past. As a whole, as a team, they play a tougher brand of hockey.”

Getting defensive

To develop that, though, involved some angst. The Capitals ended the 2009-10 season — by many measures, the best in franchise history — by blowing a three-games-to-one lead in the first round of the playoffs against Montreal. Afterward, McPhee said it was his job not to over-react. “We have a good team,” he said then, and he would not blow it up because of three straight losses, however excruciating they felt then.

In exit interviews with players after the season, as well as during self-evaluations by the coaching staff and front office, a theme developed. All three areas team officials determined they needed to address — goaltending, penalty-killing and general defensive play — had to do with preventing goals, not scoring them.

Yet Boudreau, a scorer as a player and an offensive-minded coach, didn’t overhaul the approach entering this season. Rather, he and the coaching staff tweaked it. The sell of a defensive style — to a team that had just posted the league’s best regular-season record — would have been difficult on the first day of training camp.

“If we were winning, and say, ‘Hey, listen, you’re leading the league in scoring, and doing this and doing this, but we’re going to change it into a totally defensive mode,’ they would have had a hard time believing it and buying into it,” Boudreau said. “When you don’t do it fully, then you don’t have success, and when you don’t have success, you’re sitting there wanting to do other things.”

So the first practice after the Rangers’ game became critical. This was the opportunity: Success was no longer a given. The players — with that anxiety that anything could happen — were attentive. They had no choice.

“When you go through a skid like that, you know something’s got to change,” forward Boyd Gordon said. “It could be personnel. It could be systems. But it’s got to be something.”

Though the ripples of the change were felt throughout the organization — McPhee said he regularly communicates with owner Ted Leonsis, because “we don’t want there to be any surprises” — the front office did not interfere with implementation of the new system, both Boudreau and McPhee said. When they met the morning of Dec. 13, they were like-minded.

“It’s really remarkable how Bruce and I think the same a lot,” McPhee said. “That’s why our relationship works.”

During the losing streak, the two had bounced ideas off each other. Yet they had not, McPhee said, seriously discussed a fundamental change before. But once they agreed that’s what had to happen, McPhee left his coach with one message: “How you do it is up to you.”

The coaching staff began by breaking down video of other teams, splicing clips to show players how they wanted things done. In Boudreau’s tenure leading the Capitals, they had built an unmistakable identity. If that identity was going to change, it had to be done carefully, meticulously.

On Dec. 14, the coaching staff met with the players in the small theater room at Kettler Capitals Iceplex, the team’s training facility in Ballston. According to several players, Boudreau’s approach was simple: “Okay, we’re going to try and do a couple of things different here.” Then they ran the film.

“The coaching staff did a great job of saying, ‘If you don’t know, ask,’” forward Brooks Laich said. “‘Take the time to learn this. This is going to be how we’re going to play.’”

The ensuing practice was different than any the Caps had held all season. Old habits had to be broken, new ones created.

“There were a lot of guys standing around at the beginning of practice,” Knuble said. “Usually the pace is up. But there was teaching, a little bit of standing around, a little bit of talking about stuff, a little bit more X’s and O’s than Bruce had ever done before.”

Adjustable goals

The Capitals did not have a full training camp to fine-tune those X’s and O’s. They had a day for the coaches to plan and strategize, then one practice, then a home game against the Anaheim Ducks. That night, Boudreau addressed his team in the dressing room, making the final sell of the new style.

“We might have to win the game 2-1, and we can’t get frustrated because it might be 1-1 all the way through,” Boudreau said in his pregame speech, which ran as part of HBO’s “24/7” series. “It might be 0-0. Who knows?”

Indeed, through two periods, the score was tied at 1. “Don’t get too antsy,” Boudreau reminded his team before the third. And though the Ducks scored in overtime for a 2-1 victory, Boudreau questioned neither his players’ effort nor their commitment to the new system. Instead, after their seventh straight loss, he encouraged them.

“If you play like that,” he said, “you’re going to win an awful lot of games in a row.”

That did not, though, happen right away. The Capitals lost their next game, 3-2 in Boston, and trailed 2-0 after one period in Ottawa before finally coming back for a 3-2 victory, ending what had become an eight-game skid. The style was changing, slowly, but it dominated players’ thoughts. At dinners on the road, small groups discussed the changes.

“It’s not just in the locker room,” Knuble said. “Some guys adjusted easier than others, put it that way. Guys feel like chatting. We had to talk about it.”

Convincing skilled players to prevent goals first became a process. Ovechkin had never scored fewer than 46 goals in a season; this season, he finished with 32. Winger Alexander Semin’s production fell from 40 goals in 2009-10 to 28 this season. Center Nicklas Backstrom averaged 86 points the previous three seasons; he posted 65 this year.

As Boudreau said Tuesday, “Every player in the world likes to score goals.”

“If it’s good for team, I will do it,” Ovechkin said Tuesday.

It has been, indisputably, good for the team. The words Boudreau spoke after that loss to the Ducks, the first in the new system — “You’re going to win an awful lot of games in a row” — came true. A nine-game winning streak spanned from late February to mid-March. The evidence that the change was the right course mounted.

“So many people are used to them scoring six, seven, eight goals a game, but giving up five, six, seven goals a game,” said Jason Arnott, acquired from New Jersey at the trading deadline in March. “Now, it’s 2-1, 3-2. People are wondering: Why aren’t the Capitals scoring? Well, the Capitals are winning. They’re winning.”

So the question, prior to Wednesday night’s playoff opener, becomes an easy one: Given the change, are the Capitals better-equipped entering these playoffs than they were a year ago?

“I think our mind-set is more prepared to go in than last year,” Boudreau said Tuesday. “I think everything had come so easy. We weren’t pushed, I don’t think, as a unit too hard. And this year, we’ve been pushed really hard.”