Bob McKenzie has taken his annual coach's poll to determine who should win the NHL's most prestigious trophies, and the results are interesting. First of all, of the 20 coaches polled by McKenzie, all 20 agreed that Carey Price should win the Hart Trophy as the league's most valuable player, but secondly, Ottawa's Erik Karlsson finished first in Norris voting.

It's impossible to argue that Erik Karlsson hasn't been incredible, he's been a game changer for the Senators all year, even if he was unfairly criticized the first half of the year under incompetent coaching and with very poor defense partners. He leads all defensemen in points, and is an absolute joy to watch play. There's only one problem with Karlsson winning the Norris, he may not be the best defenseman in the NHL this season.

The three leading candidates for the award are Karlsson, Drew Doughty, and P.K. Subban, so let's compare them and see who comes out on top.

Impact on teammates

Possibly the most interesting way to measure the how well a skater is playing is to look at how their teammates perform with them on and off the ice. Because of possible sample size issues, the most effective way to measure performance this way is by using shot attempt differentials, also called Corsi. This allows for relatively large data sets to work with, and a fairly comprehensive comparison. Using each player's top 20 teammates by order of descending ice time, and the team's overall performance, we can get a pretty clear picture of each defenseman's impact.

P.K. Subban

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Of all Subban's most common teammates, only one, Tom Gilbert, has seen a negative impact with him, and both are right-handed defensemen, and with just 46:37 together, it's more likely this is random noise with a bit of confusion with Gilbert playing his off side than anything. Subban's average impact on his teammates is to raise their shot attempt differential by 5.92 points, which is Herculean. It gets even more impressive when you consider how bad the Montreal Canadiens are without Subban, as the actual impact Subban has on their 45.98% Corsi is to raise it by 12.88%.

Erik Karlsson

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Like Subban, almost every one of Karlsson's teammates are far better with him than without him, though his impact is actually less pronounced. Karlsson's average impact on his teammates is to raise their shot attempt differential by 4.64 percentage points, which is phenomenal in every way, just not quite at the level of Subban. Karlsson's Ottawa Senators' baseline is also higher than Subban's, meaning the actual impact of Karlsson is lower than Subban's 12.88% impact, but a still fantastic 9.62%.

Drew Doughty

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While Doughty is undoubtedly a fantastic player, there are more players that don't benefit from his presence than the other two, and his average impact on his teammates is a much smaller raise to their shot attempt differential at just 2.30 percentage points. That's still excellent, but not on par with Karlsson and Subban. The baseline for the Los Angeles Kings is also quite high, meaning that Doughty's actual impact on the team's Corsi is to raise it by just 4.25%. It's nothing to sneeze at considering the amount and quality of minutes Doughty plays, but it's simply not comparable to Subban or Karlsson. Some will argue that it's tougher to stand out on a truly excellent team, but elite players always stand out. Better teammates would just increase how much.

Impact on offense

It's difficult to isolate offense from defensemen, and it's also difficult for experts to see much consensus on what kind of offense is more important. Some say even strength production is more impressive, but the nature of hockey tends to see most big minute defensemen accumulate most of their points on the powerplay, not at even strength.

Offense is also highly dependant on the team you play for, so when looking at individual performance, that's something to keep in mind.

Individual performance

For even strength, I limited the sample to 1200 minutes played or more, since we're looking at the big time defenders, whereas on the powerplay defensemen were required to play 125 or more minutes. Doing this, we can put the league ranks of each player in brackets for each stat. What we can see is that while Subban's team produces the least offense both at even strength and on the powerplay, he's the biggest individual producer at even strength, and right on Karlsson's tail on the man advantage.

Karlsson's even strength goal scoring is astonishing, but he's also used very differently than Subban or Doughty at even strength, allowed to take more offensive risks and much more relied upon for shooting, which is both an individual talent for Karlsson, and a team decision. Karlsson has more points than Subban this season, but it isn't so much that he's producing more often, it's that more of his minutes are used in offensive situations. Per minute, their production is very close, while Doughty lags way behind.

Team impact

Individual performance is great, but if an individual's performance isn't making their team better, it doesn't mean much. Obviously all three of these defensemen make their teams better offensively, but by how much?

Once again we see Subban and Karlsson neck and neck for offensive impact, with Doughty trailing as a distant third. Karlsson has the advantage over Subban here, although the difference is minuscule, and without context, which we'll add later by looking at deployment.

Impact on defense

How a player impacts their teams' defense is even tougher to nail down than offense, because we don't have many statistics designed specifically to measure defense. With that said, we can reverse the measurements we used for measuring the impact on team offense, and have a pretty comprehensive measure of how well each player defends.

Here's where Subban begins to separate himself from Karlsson, and where Doughty begins to catch up. All three are legitimately excellent shot suppressors, but the bigger the sample, the better Subban looks in comparison. Another factor that we can look at defensively, is how these players perform with these same measures on the penalty kill, limiting the sample to players with 150 minutes or more to take out bit players.

Unfortunately, Karlsson hasn't even played 50 minutes with his team shorthanded, which sucks for him because he's actually pretty brilliant there. For Norris voters though, his time on the penalty kill looks like zilch. In the direct comparison between Subban and Doughty, it's not even close. Subban is one of the best penalty killing defensemen in the entire NHL, and has been for four years, while the Kings actually give up more shorthanded with Doughty on the ice than when he's off it. Not exactly the statistics of a defensive stalwart.

Deployment

Here's the part where we see what truly separates Subban from his peers, specifically at even strength where most of the game is played.

While this isn't a perfect illustration of deployment, you can see clearly in the graphic that Subban faces, on average, significantly tougher opponents, and gets far less favourable zone starts. The fact is though, that's just part of the story.

Subban also has an average quality of teammate strength of just 46.2% Corsi, while Karlsson is a fair bit higher at 48.1%, and Doughty has the 4th best quality of teammates in the league at 54.6%. Essentially all this combines to give Subban the biggest uphill climb in terms of possession, offensive production, and defensive shot suppression of all three, yet he is the best at all three at even strength.

Steven Burtch of Sportsnet has created a catch-all statistic of sorts that attempts to weigh these factors and combine them with a player's possession performance to generate a generalized impact score for individual players. He calls it dCorsi (explanation here), and once again, Subban comes out on top.

Subban has a total dCorsi impact of 117.49 this season, 4.75 per 60 minutes; while Karlsson is at 54.03 this season, 2.04 per 60 minutes; and Doughty brings up the rear once more at 31.42 this season, 1.15 per 60 minutes.

So who deserves the Norris?

When it comes to these awards, there's so much subjectivity involved. A lot of it comes down to a hockey writer who saw a player have one dominant game, and that sticks out in their memory. While I don't believe that a defenseman has to play a significant amount of time shorthanded to win the Norris, they would have to be heads and shoulders above everyone else at even strength and on the powerplay in to justify it, like Subban was in 2013.

As it stands, Karlsson just hasn't separated himself from Subban at even strength enough to deserve the Norris without playing shorthanded. In fact, it seems plainly obvious that Subban has been better than Karlsson at even strength.

Putting player versus player comparisons aside, Karlsson has been easily good enough to deserve the Norris on his own, and no one should be upset if he wins. The fact is, he's a phenomenal player. Doughty though, looks like an imposter to my eye, and the impartial statistics.

It's interesting how little press Subban has received this season, while buying into the system of a coach that forces him to play against his instincts, he has become the best defenseman in the NHL while playing a completely different style than the one that won him a Norris two years ago. Carey Price's record-breaking season has overshadowed pure brilliance by Subban, something discerning fans shouldn't ignore.

Notes