NHL: Behind The Numbers – The Canucks’ Penalty Kill

A NUMBERS GAME: Can the Canucks’ Penalty Kill woes be blamed on Schneider and Luongo?

BY THOMAS DRANCE

Over the past several seasons the Canucks’ have relied on their polished, effective special teams units. Its been a key feature of this club’s DNA, and a critical reason they’ve managed to win back-to-back President’s Trophies. Just in terms of their conversion rates, they’ve been a top-ten power-play club for three seasons and a top-ten penalty killing club for the past two.

If you’ve been paying attention you already know that, through 19 games this season, Vancouver’s special teams effectiveness has atrophied in a major way. The Canucks are fifteenth in power-play percentage and nineteenth in penalty-killing percentage so far this season. Oddly enough, I’m significantly more worried about the power-play than the penalty-kill and figured I’d dive into the underlying data to explain why. This is a two part post, beginning with a look at the penalty kill.

Through 19 games, the Canucks are allowing opponents 51.9 shots per sixty minutes of power-play time. Only five other clubs are allowing shots against at a higher rate when short-handed, and most of those clubs are terrible at killing penalties. The major exception is the Ottawa Senators, who are third in the league in penalty-killing despite surrendering an astronomical 53 shots against per sixty minutes when short-handed. But they’re in the top-tier of penalty-killing clubs in the league mostly thanks to Craig Anderson’s ludicrous goaltending. It’s hard to imagine that their success is sustainable considering how permissive their penalty-killing units have been otherwise…

But let’s get back on track. Goaltenders are often called “the team’s most important penalty-killer” and that’s certainly true to a point. A dynamite goaltending performance can cover for a lot of sins, and that’s doubly true on the penalty-kill. But short-handed save percentage is not a repeatable skill, so a high save percentage on the penalty kill is mostly luck. As a general rule if your penalty-killers are giving up shots against and scoring chances against by the bucketfull, you’re going to get burned.

Maybe that’s what’s happening to the Canucks this season, though I’m not necessarily convinced. After all the Canucks penalty-kill has never been good at limiting shots against, even in seasons when the team had success in this area. For example, the club is allowing shots against at a lower rate this season than they did last year when they boasted an 86% kill-rate on penalties, and they’re only allowing roughly a shot more per sixty minutes than they did in 2010-11.

So the team’s struggles on the penalty-kill probably stem from something else, and it’s probably their goaltending. In both 2010-11 and 2011-12, Canucks goaltenders had a save percentage of .905 and .906 respectively while their team was down 4-on-5. This season that number is much less impressive, as Luongo and Schneider have combined to post an .850 save percentage with the Canucks down a man. That’s the big change here, and it’s the major reason why the Canucks are killing off fewer than eighty percent of the penalties they take through nineteen games.

Allow me to take a second to illustrate just how big an impact a .050% drop in short-handed save percentage will have on a penalty-kill’s conversion rate. If a team takes fifty shots on the power-play against the Canucks, but Vancouver’s goalies stop .905 of those shots: the Canucks’ variety of opponents would score five goals. If a team takes fifty shots on the power-play against the Canucks, but Vancouver’s goalies stop .850 of those shots against, that’s eight goals against.

So over a twenty game sample, that’s a five or six goal difference. In other words if Vancouver’s goalies had stopped .050% more of the shots they’ve faced short-handed: the penalty-kill would be chugging along at an 86.5% rate this season.

For the most part, Cory Schneider, has been fine short-handed this season. He’s posting a .873% save-percentage through ten starts this season, which is about league average and should be sustainable going forward. Roberto Luongo, however, is stopping only .826% of power-play shots faced.

These samples are only about fifty shots large, so they’re not predictive in any way and this isn’t to say that “Roberto Luongo is responsible for Vancouver’s porous penalty-killing,” which would be patently ridiculous. My point is that Vancouver’s goaltenders have both struggled short-handed this season and that it’s making the penalty-kill look somewhat worse than it is. Vancouver’s goalies are probably in for some positive regression going forward and that’ll help the team boost their penalty-kill conversion rate well north of 80% going forward.

That is, unless the club has been way too reliant on their netminders in short-handed situations over the past several years and it’s just now catching up to them. That’s definitely a possibility too, and a grim one at that.