The Boston Bruins ended 2017 as the hottest team in the National Hockey League. Their hot streak continues after their first game of 2018.

Even with Brandon Carlo’s hiccup that led to Jordan Eberle’s first-period equalizer, the Bruins received plenty of contributions in their 5-1 victory over the Islanders Tuesday night.

Here is what we learned as the Black and Gold extend their point streak to nine straight games.

Bruins’ depth wears down Islanders

A healthy lineup over the last two months is going a long way for Bruce Cassidy and the rest of the coaching staff.

From the top trio of Brad Marchand, Patrice Bergeron and David Pastrnak to the fourth line of Tim Schaller, Noel Acciari and Sean Kuraly — to the three defensive pairs and the goaltending tandem of Tuukka Rask and Anton Khudobin — the depth is benefiting the B’s.

Their well-rounded roster was on full display at the Barclays Center. Three of the four forward trios contributed in the scoring department, including two goals from the aforementioned first (Marchand and Bergeron) and fourth lines (Schaller and Acciari).

Third line winger Danton Heinen — again with Riley Nash and David Backes — got the Bruins on the board on a set faceoff play to set the offensive tone with his 10th of the year at 8:17 of the first.

The Bruins had a significant zone time advantage in Brooklyn. On the other end, Rask (25 saves) and the B’s D kept John Tavares and the high-tempo Isles out of the prime scoring areas.

“We had four lines contributing, six D and Tuuks [Rask] was great tonight too,” Marchand told reporters after tallying his 200th career assist on Bergeron’s go-ahead goal in the second period. “When we play like that as a group, we have all lines rolling, so [we’re] tough to play against.”

Pastrnak finding different ways to contribute

He doesn’t have a goal in 10 games, but Pastrnak is still performing at a high level.

Pastrnak added his seventh assist in that 10-game stretch on a beautiful feed to Marchand during a 2-on-1 that gave the Bruins a 3-1 lead near the midway point of the third period. The 2014 first rounder also notched a game-high five shots on goal — with Marchand and Islanders forward Josh Bailey — and was a plus-two in 12:40 of ice time.

“Listen, he’s a goal-scorer and they want to score,” Cassidy said about Pastrnak’s effort to NESN’s Jack Edwards and Andy Brickley.

“[He] certainly had some chances there. You know Bergy [Bergeron] found him a couple of times and it didn’t go his way – and a goalie made a great save on one – and then he makes a heck of a play to Marshy [Marchand]. Other guys might have forced their way in there and tried to score, but he made the right play and gave us an insurance goal and he did the things we asked. He’s getting better and better at that 200-foot game and it’s something we’re going to need so good for him.”

Slowly, but surely, the offensively gifted Pastrnak is finding a rhythm in the neutral and defensive zone.

Time for Adam McQuaid to return?

McQuaid is eager to return after healing from a tibia injury sustained in October. Given the Bruins’ roll of late, Cassidy has little reason to make changes to his lineup.

The Bruins have an even layout with their left and right-shot defensemen. Inserting McQuaid means sitting Carlo or Matt Grzlecyk.

Carlo has had his share of ups and downs in his sophomore season but has shown abilities to bounce back after rough patches as seen following his first-period turnover. Grzlecyk, meanwhile, is finding his footing in his second go-around since being recalled from Providence and gives the Bruins an extra offensive-minded blue-liner (along with Krug and Charlie McAvoy).

Another rough outing could put Carlo on Level 9 for a game or two. McQuaid provides a stable, stay-at-home option, but there’s no doubt Cassidy will stay with his current group as long as the Bruins continue to roll.