The play was emblematic of the season thus far.
Defenseman Alex Goligoski charged up the boards inside the blueline, trying to keep the puck in the offensive zone midway through the third period of a 4-4 game. Shawn Thornton of the Boston Bruins got to the biscuit first, however, and chipped it past the oncoming Goligoski and into the neutral zone.
From there, the Bruins' fourth-liner joined rookie Brad Marchand on a two-on-one rush into the Pittsburgh end. With Penguins' defenseman Ben Lovejoy covering Marchand, Thornton rifled a shot over goaltender Brent Johnson's glove from close range, giving Boston its first lead in a 7-4 victory at CONSOL Energy Center Wednesday night.
Through the first two periods of the contest, the Penguins (7-8-1, 15 points) had played head coach Dan Bylsma's attacking philosophy to near perfection, outshooting Boston 34-20 en route to a 4-2 lead through 40 minutes. The embattled power play had just converted for the third straight game and the Penguins had kept the Bruins hemmed in their own zone for long stretches of even-strength play as well.
Boston fought back early in the third, scoring twice in 15 seconds on gorgeous shots fired by Nathan Horton and gargantuan defenseman Zdeno Chara. All was not lost for the Penguins, but after Goligoski's lost gamble, the Bruins stole the energy away from the home side and eventually completed a five-goal third period.
What has been the Penguins' biggest problem?
Under Bylsma, defensemen have the freedom to pursue pucks, lead rushes up ice and otherwise take calculated risks. But with this power comes the responsibility to read the play correctly, an area in which the Pens' blueliners have been maddeningly inconsistent through the first 16 games of the campaign.
After Thursday's practice, Bylsma spoke of the necessity of discretion from his defensemen, especially on what he called "50-50 plays." To be sure, allowing skilled rearguards like Kris Letang (15 points), Goligoski (10) and Paul Martin (eight) to spread their wings has paid off offensively; the Penguins' defensemen have recorded the post points in the NHL thus far.
But while Martin (via New Jersey) and fellow newcomer Zybnek Michalek (Phoenix) came to Pittsburgh this summer from more conservative teams, giving them a grace period in grasping the aggressive system, D-men like Goligoski and Letang have played more than 100 games for Bylsma and should be too familiar with the philosophy to consistently expose their teammates through ill-timed risks.
Stalwart blueliner Brooks Orpik, the longest-tenured Penguin, hinted as much after Wednesday's game, telling the Pittsburgh Tribune-Review, "We can't have our defensemen playing like forwards with a 4-2 lead in the third period."
What Orpik didn't say was that the mistakes are not limited to the offensive end. Poor defensive-zone coverage plagued the team in road losses to Dallas and Anaheim last week, and the problems continued Wednesday. A prime example was 42-year-old Mark Recchi outsmarting Michalek behind the net to set up Boston's sixth goal in the final minutes.
In a young season full of worries for Pittsburgh hockey fans -- from Marc-Andre Fleury to the power play to a 2-5 record at home -- a lack of cohesion on the blueline could ultimately be the most lethal to the Penguins' Stanley Cup aspirations.