Most people following the Montreal Canadiens haven't quite realized it, but the powerplay has been terrible for nearly a calendar year. Since December of last season, including the playoffs, the Canadiens have played 87 games. In those games, they've had 286 powerplay opportunities at 5-vs-4, and scored just 34 times.
What that means is that the Canadiens have, for essentially a full year and over a full season's worth of games, been working with a powerplay that capitalizes just 11.89% of the time. Since the 07-08 season, only the 13-14 Florida Panthers have converted at a worse clip over such a large sample, one team of 180 possible teams over that span. That's really, really, really bad.
This year's powerplay is the worst edition yet, although a large part of that is a run of bad luck on top of bad tactics. The Canadiens are scoring on just 3.92% of their shots while up a man, compared to 7.88% at even strength, which is still below league average.
With that said though, the powerplay isn't just getting bad bounces, they are legitimately horrible there. Over the last 87 games, they're 29th in the NHL in shots generated per 60 minutes, 26th in unblocked shot attempts, and 22nd in shot attempts. They've also allowed the fifth most goals against over that period with nine, approximately one every ten games.
It's not personnel
Players like P.K. Subban, Andrei Markov, Max Pacioretty, and Tomas Plekanec have shown they're capable of being among the top powerplay producers in the NHL over the last several years, and when you're adding in Alex Galchenyuk, Brendan Gallagher, and P.A. Parenteau, you're in a good situation in terms of who you can put out there.
Tactically though, the powerplay is awful. It used to be that the entire powerplay ran through P.K. Subban's shot, which worked for awhile, until opponents started over-checking him. A smart powerplay would then shift focus to working the puck down low against the three remaining opponents, or to play with the puck away from Subban more often to get him free, but instead the Canadiens have chosen to have Subban on the right side a majority of the time, keeping him out of one-timer position.
It's as if the Habs' staff saw that other teams wanted to take Subban's shot away, and took it away for them. Really, what they should have realized is that teams overplaying Subban's shot leaves more room for a sniper like Max Pacioretty.
Sergei Gonchar's addition seems to have shuffled the strategy a bit, with the Canadiens going with two left-handed defensemen on the first wave, and two right-handed defensemen on the second wave, but this doesn't fix their zone entry problem. It doesn't fix their lack of movement to get into scoring areas and shake checkers, and it doesn't address their propensity for giving up shorthanded markers, especially with two old Russians on the back end who can't really skate anymore.
The Boston exception
Arpon Basu of LNH.com and I have been speaking about this a bit over the last few months, and he went back and ran some numbers of his own, specifically about the Bruins being the weird exception to the rule of the Habs having a horrid powerplay. Counting 5-on-3 chances, the Canadiens have put up a 26.7% powerplay conversion rate against the Bruins since December 3rd, while going 11.1% against the rest of the league. Part of that is likely the peril of small samples, but even in the playoffs the ice cold powerplay was a difference maker against Boston.
For whatever reason, the Canadiens powerplay is completely ineffective against 28 teams, and absolutely killer against one. That isn't really a method for success when you have to beat four different teams to win a Stanley Cup though.