But only when that emotion doesn't take over, and especially against their age-old rivals.
On Monday night, with the Montreal Canadiens visiting TD Garden, the Bruins knew what type of game would play out. But for them, it ended in a 2-1 shootout loss that snapped the League's longest winning streak of the season at 12 games.
Early in the first period, just over a minute in, Milan Lucic took a hit from Alexei Emelin. Zdeno Chara reacted and received a roughing penalty as a result. The Bruins killed it off, but it would be a precursor to their first 40 minutes of play.
At 6:39 into the opening frame, Emelin gave the Habs a 1-0 lead on the man-advantage when his drive from the slot deflected off Chris Kelly's stick and past Tuukka Rask.
Kevan Miller had been called for a cross-check on Dale Weise. The knowingly strong Miller then stood up for himself, when Travis Moen challenged him to a fight.
But it wasn't necessarily those types of penalties that plagued the Bruins, who ended the night with 17 penalty minutes, having to kill off four penalties alone in the second period.
It was the momentum Montreal stole from the Bruins when the penalties were in retaliation, or from frustration. It was when Boston's usually controlled emotion and composure got away from them.
"We were just a little bit off the mark there," said Bruins Head Coach Claude Julien. "Typical, I guess, start from a team that comes back from a road trip and plays its first game at home. Took us a while to get going. But you know, early penalties kind of just took the momentum away from us and gave them some momentum."
"Eventually we got ourselves back in the game and unfortunately, got settled in a shootout."
The Bruins did battle and finally get past Peter Budaj to even the score at 1-1 with 5:26 left in regulation. Patrice Bergeron lined up in the slot and tipped in Dougie Hamilton's drive from inside the blueline for the equalizer.
It came as result of a power play, one of four given to the Bruins in the third period. Once they harnessed their emotions, it brought them success.
"We just [had to] stay with our game plan," said Captain Zdeno Chara. "We were spending more energy on playing hockey and focusing on scoring a goal than being more physical and emotional."
While the Bruins killed off the rest of the penalties, after Montreal capitalized, it took away from the sustained four-line attack that has made them so successful throughout the past two months, and recently, during the streak.
Coming off a week-long road trip, through three time zones, they needed to get their legs going early. Having to kill off penalties didn't help the cause.
Early in the second period, Brad Marchand and PK Subban were battling for positioning after a faceoff. Marchand caught him with a high stick.
"At times, absolutely," said Julien, when asked if 'undisciplined' is a way he would describe the game. "The Marchand penalty was frustration because he got tripped on the faceoff before — it wasn’t called. Those are things that are going to happen in a game and you can’t retaliate by taking a bad penalty."
"[Johnny] Boychuk’s penalty was a bad one too, so you know, there’s discipline, but they didn’t score on those, so that’s not why we lost. But I think we have to be better disciplined against them."
Later in the second period, while killing off a slashing penalty called on Jarome Iginla, Chris Kelly backchecked Subban heading into the Bruins' zone. Boychuk saw his chance for a hip check and got a piece of Subban, who then got under the defenseman's skin, gave him a shove while he was down, and caused the Bruin to retaliate.
Boychuk isn't necessarily the easiest to goad into a reaction.
"They do do that, but you've got to keep your cool and be disciplined," he said.
Throughout their consistent stretch (they are 20-2-4 in their past 26 games), the Bruins have preached improving from game to game. Limiting defensive breakdowns had been high up on the list.
This game was a good reminder of the importance of discipline moving forward.
"Yeah, especially in the playoffs. You can't be taking penalties in the playoffs like I did, that's for sure," said Boychuk. "You've just got to keep your cool and don't worry about anything but the game."
"Against them, a lot of times the emotions take over too much for us and we kind of slip from our game plan a little bit," said Rask, who made 21 saves on 22 shots through regulation and overtime.
"It’s an emotional game, and when stuff happens you have to react, and sometimes you overreact."
They key to not getting drawn into penalties?
"Simple — you don’t let it happen," said Julien.
"Other than tonight, most of the time against every other team we’re pretty good at keeping our composure and just focus on what we need to do to win," said Milan Lucic. "Down the stretch, we can’t let things like that bother us. We just need to focus on our game and what we need to do to have success."
"We’re going to play that physical type of style and sometimes [the way] things are, you’re going to have reactions, emotional reactions going both ways, and you’ve got to expect it from here on in."
As the night continued, the Bruins refocused themselves on the game itself. When they did that, it gave them four power play opportunities in the third period, along with plenty of sustained pressure five-on-five.
"I thought that as the game went on, we were battling and focusing on just playing the game," said Chara. "We were emotionally and physically attached. It’s always, obviously, a big game, every time we play Montreal. But I thought that as the game went on, we were obviously putting focus on playing the game instead of everything else."
"We played hard, we kept with it, and we kept ourselves in the game," said Julien.
"So you can’t win 12 in a row and lose one in a shootout and say, ‘I’m really disappointed in my team.’ I don’t think so. I think our team is okay, and we've got another great challenge coming up for us - which is what we want - and that’s Chicago on Thursday."
Though the streak came to an end, the Bruins enjoyed it as a byproduct of their solid play. It didn't define where there game was at; it showcased it. The effort was still strong against Montreal, the compete level was still there.
"That's not really a goal, to go on a long streak like that," said Marchand. "It's to play our best hockey and play the way we need to every night, and it just shows that when you do that, we're going to give ourselves an opportunity to win every night. And if we continue that, we're going to win a lot more games and that's what we need going into playoffs."
"We managed to get that point, and I guess, you know, if we have a weakness, it’s pretty obvious — it’s in the shootouts," acknowledged Julien.
"So, I don’t care about that, because that doesn’t happen in playoffs."