Bruins' improved defensive play among reasons for climb in standings

The Coaches Room is a weekly column by one of four former NHL coaches and assistants who will turn their critical gaze to the game and explain it through the lens of a teacher. Jim Corsi, David Marcoux, Paul MacLean and Joe Mullen will take turns providing insight.
In this edition, Mullen, a former assistant with the Pittsburgh Penguins and Philadelphia Flyers and 2000 player inductee into the Hockey Hall of Fame, talks about teams that have been playing better recently.

With the season past its midway point, I thought it would be a good time to look at some of the teams that have picked up their play recently.
The Eastern Conference team that has improved the most to me is the Boston Bruins. They have not lost in regulation since a 5-3 defeat against the Washington Capitals on Dec. 14, going 10-0-4 during that stretch. Since going 6-7-4 in their first 17 games, they are 19-3-4.
One of the keys for the Bruins is they're keeping their goals against down. Goaltenders Tuukka Rask and Anton Khudobin have been playing very well, and the Bruins allow 2.49 goals per game, second-fewest in the NHL, behind the Los Angeles Kings (2.43).
Since Nov. 16, they've allowed a League-low 53 goals in 26 games. During the same stretch they've scored 92 goals, third-most in the NHL.
Their big line of Brad Marchand, Patrice Bergeron and David Pastrnak has been outstanding. Marchand leads the Bruins with 43 points (19 goals, 24 assists), Pastrnak is second with 40 points (18 goals, 22 assists) and Bergeron is third with 35 (16 goals, 19 assists).

They've also gotten a good contribution from some of their younger players. Rookie forward Danton Heinen has 31 points (10 goals, 21 assists), and rookie forward Jake DeBrusk has 24 points (10 goals, 14 assists). Rookie defenseman Charlie McAvoy has 24 points (five goals, 19 assists) and is averaging 22:47 of ice time per game, second on the Bruins to captain Zdeno Chara (23:21).
Getting forwards David Backes (colon surgery) and David Krejci (upper-body injury) back in the lineup has helped them out lately too. But it just seems like everybody's been chipping in.
Here are some of the other teams that have been playing better recently:

Pittsburgh Penguins

It looks like Pittsburgh is getting its game back together after struggling to find consistency for much of the first half. It had won four in a row entering a three-game California road trip that began against the Anaheim Ducks on Wednesday and continues against the Los Angeles Kings at Staples Center on Thursday (10 p.m. ET; NBCSN, SN360, ATTSN-PT, NHL.TV).
The Penguins won the Stanley Cup the past two seasons. That's a lot of hockey for their core players. And as the defending champs, they're everybody's main target. Teams want to beat the best.
But the Penguins always seem to find a way during the season to battle back and get back in the running. That's what they're doing now, but it took some time.
They made a lot of changes up front. They lost veteran forwards Chris Kunitz (Tampa Bay Lightning), Nick Bonino (Nashville Predators) and Matt Cullen (Minnesota Wild) during free agency. But rookie forwards Dominik Simon (one goal, four assists in 12 games) and Daniel Sprong (two goals, one assist in eight games) have made a difference since being called up from Wilkes-Barre/Scranton of the American Hockey League in December.
It's a great opportunity for these young players to play with great players such as Sidney Crosby and Evgeni Malkin.

New York Islanders

The Islanders had won three in a row before a 4-1 loss to the New Jersey Devils on Tuesday.
I like what they're doing entering their game against the Bruins on Thursday (7 p.m. ET; SN360, MSG+ 2, NESN, NHL.TV). They're getting that second layer of scoring from rookie center Mathew Barzal's line with Anthony Beauvillier and Jordan Eberle. Barzal had a five-point game (two goals, three assists) against the New York Rangers on Saturday and a three-point game (one goal, two assists) against the Montreal Canadiens on Monday. Beauvillier has played well since being recalled from Bridgeport of the AHL, with five points (four goals, one assist) in four games, and Eberle has seven assists in the past four games.
That line's production has been important with forwards Josh Bailey (lower body) and Andrew Ladd (upper body) sidelined with injuries.
The main concern with them is their goals-against; they've allowed the most goals in the League with 167. So that's the area they must concentrate on.

Calgary Flames

The Flames have made a nice push with seven wins in a row entering their five-day schedule break, which ends Saturday. Their big line of Johnny Gaudreau (two goals, 11 assists during the winning streak), Sean Monahan (four goals, six assists) and Micheal Ferland (four goals, five assists) is going well, and it seems their defensemen are jumping up and helping the offense a lot. Defensemen Dougie Hamilton (four goals, two assists) and Mark Giordano (two goals, four assists) each have six points during the winning streak.
Goaltender Mike Smith has been a big part of the Flames' turnaround, going 6-0-0 with a 1.99 goals-against average and .941 save percentage during the winning streak. He handles the puck so well. When he's moving the puck it takes a lot of pressure off the defense and gives them a chance to transition to offense quicker.
One thing they'd like to do is play better at home, where they are 12-11-0. They play six of their next seven at Scotiabank Saddledome.

Colorado Avalanche

The Avalanche also have won seven in a row entering their game against the San Jose Sharks on Thursday (9 p.m. ET; ALT, NBCSCA, NHL.TV) and are 8-1-1 in their past 10. Goaltender Jonathan Bernier has carried the load while Semyon Varlamov has been recovering from a groin injury, going 6-0-0 with a 1.27 GAA, .962 save percentage and one shutout in his past six games.
Center Nathan MacKinnon is having a great season. He has 14 points (five goals, nine assists) during the winning streak, and with 54 points (20 goals, 34 assists) in 43 games, he's already surpassed last season's total of 53 points in 82 games.
There's maybe a little bit more pressure on MacKinnon, 22, this season, but I think he likes that. He accepts that role.
Another reason for the Avalanche's turnaround is their special teams play. Their penalty kill is third in the NHL at 84.5 percent, after being 29th in the NHL last season at 76.6 percent, and their power play, which was last in the League last season at 12.6 percent, is ninth at 21 percent this season.
To go from 22-56-4 and last in the League last season with 48 points to contending for a wild card into the Stanley Cup Playoffs in the Western Conference is big jump in a short amount of time.