Heading into this season there were two main concerns for the Bruins -- secondary scoring and inexperienced defense.
The former concern has lessened in the wake of the team's offensive outburst during their two-game sweep over the Philadelphia Flyers.
The latter has been a moot concern since the puck dropped on opening night.
The skepticism was valid for a young Bruins defense that not only lost a future Hall of Famer in Zdeno Chara but also a top offensive defenseman in Torey Krug.
Though it stings when thinking about certain attributes the Bruins lost when saying goodbye to Chara and Krug, the two former Bruins defensemen didn't play without their flaws.
Chara’s inability to keep up with the pace of play made it difficult for him to defend one on one, as well as effectively transition the puck.
Krug’s effort and compete level was second to none but despite his skating and passing ability, opposing forwards with longer strides were oftentimes able to take advantage on the forecheck.
Chara’s lack of foot speed and Krug’s lack of size were both addressed via their successors on the Bruins’ blueline.
Charlie McAvoy is clearly leading the way, playing 24:53 per night, but Jakub Zboril (19:45), Matt Grzelcyk (19:43), Jeremy Lauzon (19:19) and Brandon Carlo (18:44) are all averaging nearly 20 minutes of ice time per game so far this season as well.
Bruce Cassidy is clearly encouraged by what he is seeing from his young defense and is rewarding them with trustworthy minutes.
So, what exactly are they doing so well? Let’s start in the offensive zone.
Footspeed and mobility is enabling the Bruins defense to pinch down along the boards, interrupt breakout attempts and keep plays alive.
Furthermore, their quick skating allows them to straddle the blue line and find better shooting lanes to the net.
When opponents are quick to skate out and block shots the Bruins defense has been moving laterally across the blue line to adjust their angle to the net.
Moving to the neutral zone... once opponents inevitably enter the neutral zone with possession, the Bruins are maintaining efficient gap control.
Gap control is the distance a defenseman keeps between himself and an approaching opponent in possession of the puck. Ideally, a little more than a stick's length away is the appropriate gap control.
With gap control from the defense and back-checking pressure from the forwards, the Bruins effectively shrink the neutral zone on opponents helping to prohibit entry into their own defensive zone.
Finally, the defensive zone.
Due to the Bruins' strong neutral zone structure, teams will often counter with a dump and chase strategy.
Fortunately, this rendition of Bruins defenders all possess the skating ability, edgework and agility to fend off forehcheckers and retrieve pucks.
What’s even more encouraging, they all showcase composure with the puck and execute smart, effective breakout passes.
Mobility leads to puck possession, which in turn leads to offense.
The speed and skill from this young group of Bruins defenders is quickly turning a concern into a strength.