The Bruins were very clear about their plans. Before the trade deadline, they wanted to improve their defense by adding depth. And while their new pieces have yet to be utilized — Andrej Meszaros and Corey Potter sat out Thursday’s game — the defense certainly improved against the offensively dangerous Capitals.
Boston had been loose since the Olympic break, not playing its traditionally structured, stifling style. It had shown in the results.
That wasn’t the case Thursday.
“Today it was the best in a long time,’’ said goaltender Tuukka Rask, who earned his league-leading sixth shutout with a 3-0 decision at the Garden. “You always want to play good defensively, right? We’ve kind of slipped from that a little bit, but I think guys were sharp mentally today — that’s all it is, it’s just mental errors and not doing the things you’re supposed to do. So today we fixed that and everybody feels good about it.”
Washington managed just 16 shots on net, with just eight coming in the first two periods as the Bruins built a 2-0 lead. Meanwhile, Boston was peppering Braden Holtby with pucks, 43 in all.
“It was a very strong effort for 20 minutes at a time,” Zdeno Chara said. “We knew they would put a lot of pressure on us and they would probably open up the game more. We just tried to stay patient and play a really strong, structured game. We held them to  shots.”
Said coach Claude Julien, “You take away their time and space the way we did tonight, it makes us a much better team, and I thought we did a great job of getting on them quickly and not giving them opportunities to make too many plays.”
Part of that was the fact the Bruins were not called for a single penalty, the first time that has happened since Feb. 24, 2012. They had allowed two power-play goals on Saturday to Alex Ovechkin — who was nearly invisible Thursday — and the league’s second-best power play.
But not only did the Bruins see their best defensive effort — and therefore best all-around game — since the Olympic break, they also saw the continued evolution of Loui Eriksson. The forward was back in the lineup after missing Tuesday’s game with an infection in his heel, and scored his first goal since Jan. 27.
The Olympics were good for Eriksson, who is starting to look like the player the Bruins thought they were getting when they traded for him this summer, before he ran into a seemingly endless stream of bad luck in Boston.
“I think he’s getting better and better,” Chara said. “It’s been, for sure, not an easy year for him with injuries. When you’re kind of coming and going out of the lineup it’s tough to get that feeling and your game back. I think the Olympics probably helped him to gain his confidence and play-making capabilities.
“Now he’s getting better and better, so for sure it’s something that we like to see.”
Eriksson put the Bruins ahead, 2-0, at 8:20 of the second period. He took the feed from Carl Soderberg on the wraparound, and put it over Holtby for his seventh of the season. It was yet another example of the Bruins’ third line’s growing confidence and results.
“We had to give him that opportunity to find his game after going through those two serious concussions and that really set him back,” Julien said. “But I think we’re starting to see the smart player that we all talked about at the beginning of the year, both ways. He makes smart plays and he defends well.”
They had gotten their first at 3:05, with Gregory Campbell redirecting a shot from Patrice Bergeron past Holtby on a delayed penalty for his fourth goal in the last four games. The Bruins added an empty-netter by Brad Marchand at 18:26 of the third.
But on Thursday, the offense was there to support the defense, a change from recent games. Even with the same defensive group as before the break, even against a team that had victimized them for four goals less than a week ago, the Bruins demonstrated they’ve come far in a short time.
“We played for the full 60, we played through our system, our whole back pressure was great,” Bergeron said. “We didn’t give them too many odd man rushes. And we played well, we played tight, and just respected our system. When we do that, good things happen.”