The New York Islanders were flying.
Even though the Penguins never trailed in the series, the Islanders outplayed their division counterparts through most of their first-round tilt. In most of those games, the Islanders -- those Islanders? -- were a good facsimile for the 2012 Flyers.
Unstoppable in transition. Quick on the forecheck. Too fast and too skilled and too unpredictable to track through the middle of the ice.
Eventually, the Pens would dispatch the Islanders. Pittsburgh's largess of talent eventually overpowered the thin-rostered Isles, and Tomas Vokoun stepped up where Brent Johnson wasn't trusted to in relieving a shattered Marc-Andre Fleury for Games 5 and 6.
If the Islanders were so close to stealing that series from the Pens (and they were), how did the Penguins survive? What was the difference between 2013 and 2012?
Was it really the penalty kill?
That penalty kill?
A cursory look at the big bold stats says yes. The Penguins killed off 18 of the Islanders' 20 chances on the man-advantage. The year before, they killed just 11 of the Flyers' 23 power play chances. That percentage increase, from a historically awful 47 percent against the Flyers to a nice, round, 90 percent against the Isles, was a key difference. Philadelphia was able to pot 12 of their 30 goals on uneven ice.
The Islanders might have endured a better fate had the Pens given them the two big handfuls of power play goals the Flyers enjoyed. Pittsburgh outscored the Islanders 25-17, but with the benefit of two big blowout wins, that advantage looks better on paper than it often looked on the ice.
Perhaps the key difference between this spring and last was the churlishness of the Pens' defenders in the slot.
Gone from last year's unit were Jordan Staal and Zbynek Michalek, two PK regulars who, while sound defensively, were nothing if not ghosts in front of Marc-Andre Fleury's cage. The Flyers were able to skate and pass through the slot unabated, and tortured Fleury with so many uncontested scoring chances.
A direct focus on changing that passivity helped to make the unit tougher to play against, but personnel changes were made as well. Brandon Sutter was key that turned the Staal-to-Carolina deal, and he has assumed Staal's old defensive responsibilities well despite a rough start to his first postseason. With Michalek back in the friendly confines of Phoenix, trade acquisition Douglas "Great Wall of Sweden" Murray has turned the area in front of Vokoun's cage into a much less friendly place. Mark Eaton, left for vultures by the Islanders after last season, has been a shot-blocking revelation.
Oh, and Vokoun hasn't been bad in his role as the new last line of defense.
The new guys haven't been the only ones to contribute, though. Matt Cooke and Pascal Dupuis have been absolutely stellar in the penalty-killing roles, Paul Martin and Brooks Orpik have rediscovered their effectiveness in PK situations and Craig Adams has been quietly reliable in his favored role.
Before the shortened 2013 campaign, Pittsburgh's penalty kill had traditionally been good under Dan Bylsma in the regular season. The Penguins were south of 80 percent on the PK this season, but quickly turned their fortunes when the postseason began.
Aggressiveness and personnel have been most responsible for the change. Pittsburgh has only allowed one more power play goal (4) than it has scored shorthanded (3) in these playoffs. It's an impressive turnaround for one of their most glaring shortcomings just one postseason ago.
The Penguins now await (and await, and await...) the Boston Bruins in the Eastern Conference Finals. The Penguins shook off whatever medicine the Islanders fed them in the first round to rediscover their total regular season dominance against the Senators. And, like the Islanders, the Senators fared poorly against the Penguins' penalty kill -- scoring just twice in 19 chances, or an 89 percent kill for the East's first seed.
Boston has some big names on their top power play, and have scored 7 man-advantage goals (21.9 percent) this postseason, second only to Pittsburgh among the remaining four teams.
If Pittsburgh can limit Boston's chances like it has already done to Ottawa and New York, the Bruins may find it impossible to overcome the Penguins' so-far unstoppable offense.