On December 15th, the day after the Penguins defeated the Boston Bruins, it was announced that Kris Letang had sustained a lower body injury. He was moved to injured reserve two days later. The Penguins defensive woes were exacerbated by an injury to Trevor Daley on December 16th. Their seven game winning streak was over, and the sad realization that the Penguins are a very different team without Kris Letang and his 26 minutes of ice time and Daley and his 20 minutes of ice team has firmly set in.
Since Letang’s injury, the Penguins have lost to the Kings (1-0), the Leafs (2-1), and the Blue Jackets (7-1). They have managed to defeat the Rangers handily (7-2) and the New Jersey Devils (4-1). Despite these divisional wins, this is a losing record and includes an embarrassing loss to the Blue Jackets. In each of the Penguins losses during this stretch, the Pens have not scored more than one goal. Simply put, the Penguins are not constructed to win a 1-0 game.
The Penguins lead the league in goal scoring with 3.4 goals scored per game. The team is designed to allow elite talents like Crosby and Malkin fill the net. Their defense only ever has to be slightly better than adequate. When the Penguins score three goals, it is very likely that the Penguins will win the game. However, when the Penguins have only managed to score 1 goal a game they have lost every time. This is true against top tier teams like the Blue Jackets, and against middle of the pack teams like the Kings, and lesser teams like the Leafs.
A big concern for the Pens with these injuries is the power play. The Penguins power play is currently 5th best in the league at 22.2%. The power play has actually been better since the injuries, at over 27%. This is a curious example of using one statistic to prove an erroneous point. The Penguins power play should certainly be worse off after losing those two great puck-playing defensemen.
Relying on only one stat, whether it is an archaic one like plus/minus or a modern or “advanced” stat like Corsi or Fenwick is never a good idea. One statistic, no matter how advanced, can never paint the total picture of what is happening on the ice. That is certainly the case here. Statistics are predictive. The chances making a better prediction improve when you include multiple statistics that are all in functioning to reinforce each other.
The Pens power play should not have improved with the injured sustained to Letang and Daley. Although it is possible for the remaining defensemen to play out of their collective minds and actually improve the power play, that simply is not that case. In this case, the power play statistic is bloated by the Rangers game. The Rangers game is an outlier. During the Rangers game, the Pens power play was scoring at 60%, which is roughly three times higher than where it is during the rest of the season. Removing the Rangers game brings the Penguins power play during this stretch of games without Letang down to 15.38%.
This is a drastic decline in productivity on the power play and it would not be surprising to see the Penguins score only one goal a game, even with their elite forwards. This is what to expect when a team loses two of their top four defensemen. Crosby may win the Hart Trophy, but without puck moving defensemen like Letang and Daley, the Penguins are in trouble.