An off year from Erik Karlsson has opened the Norris Trophy field to a whole group of defencemen this year.

Some players are getting more buzz than others at the moment, with a recent PHWA survey leading to Victor Hedman being the front-runner, with Drew Doughty and John Klingberg behind him. However, I think the field is way bigger than just three players, and I’ve identified four more who are deserving of recognition.

We’re going to get into an extreme level of detail using a lot of data here, so what I’m going to do is present a graph, explain what’s in it and what we’re looking for, then after all the data is explained, we’ll go through each player’s case for the Norris. Then I’ll rank my list.

We’ll be breaking down the seven candidates in three different ways: we’ll examine the difficulty of their minutes for context, then look at their on-ice performance and puck management relative to their peers, followed lastly by a peer into their raw involvement in play offensively and defensively.

With all that said, let’s break down the context of our top-seven contenders in no particular order: Klingberg, Doughty, Karlsson, P.K. Subban, Alex Pietrangelo, Brent Burns, and Hedman.

We have three categories to contextualize performance here: how much teams rely on these players, the stability of their defence pairings, and the difficulty of the minutes they play.

When looking at team reliance, what’s measured is the percentage of their team’s total ice time in that situation in the games the defenceman has played that they’ve been on the ice for.

Partner stability is fairly self-explanatory, but the reason for focusing on it is that it’s usually simpler to play your game when you can predict what your partner is doing, though if your partner is bad, that’s a different story.

In difficulty of minutes, zone starts give an indication of whether a player is playing uphill most shifts or not. The spread in quality of competition is tiny, due in part to on-the-fly shifts and how different bench-management decisions are in road or home games, but they’re still worth looking at. Quality of teammates is one of the biggest impacts on player performance, so that’s something to focus on.

In order to win a Norris Trophy, you can’t just be a good player on a good team; you need to stand out from those teammates as well. Measuring on-ice performance we’re using three metrics from Corsica.Hockey: Corsi, goals for, and expected-goals-for percentage relative to teammates.

Looking at puck management, we have to break down players in the structure they play in, by comparing them to other defencemen on the same team. We’re doing that two ways here: turnover rates, and pass-success rates. Turnover rates in this graph are inverted so that positive numbers mean a better turnover rate by that percentage than team average.

Finally, we can get into rate stats. Most data on the graph is presented in per-20-minute increments, but point production is on a per-60-minute basis in order to actually register on the graph with events that occur far more frequently.

Production is good, but in under a full season factors beyond a player’s control can contribute to that production, so we have to look at the underlying offence these defencemen are creating, using the number of scoring chances they generate for their teammates at even strength, and how well they move the puck in the offensive zone.

Defensively, how engaged players are in winning puck battles and recovering loose pucks is a big difference-maker, changing possession to move the play out of danger. Also important are stick and body checks to loosen those pucks in the first place, as well as pass blocks in the defensive zone to stop scoring chances before they happen.

With all that out of the way, let’s break down these defencemen.

John Klingberg

Klingberg is getting all sorts of praise for leading all defencemen in points (seven more than any other blueliner), but he’s also in the midst of a breakout season defensively. He doesn’t play much short-handed, but neither do Karlsson or Burns, so I don’t see it as much of an impediment.

Klingberg clearly the play-driver on his pairing with Esa Lindell, but Lindell has been solid without Klingberg as well.

Despite his offensive reputation, Klingberg has started more shifts in the defensive zone, though he does benefit from playing loads of time with the Stars’ top line, and he faces about an average quality of competition.

Klingberg has the best impact on teammate goals of any top defenceman this season, with similarly excellent expected goals, and solid possession impacts.

He has been brilliant with the puck this season, in contrast to years past in which he made frequent mistakes as a risky puck mover. He’s better than team average in pass-success rates and turnover rates in every zone.

It’s no surprise then that offensively, Klingberg’s biggest strength is his passing. He’s absolutely running away with the league lead in assists and primary assists among defencemen, both at even strength and on the power play.

Defensively, Klingberg isn’t our strongest candidate, but his impact on scoring chances and shots against is incredible thanks to his transition ability once the puck is won.

If you think Klingberg is getting buzz for the Norris just because of his point production, you’re sorely mistaken; he’s been a fantastic player all over the rink this season.

Drew Doughty

The Norris winner in 2015-16, Doughty’s season has been split fairly evenly between Jake Muzzin and Derek Forbort, and while he and Muzzin have a complementary chemistry, Doughty definitely carries Forbort to a serious degree.

The amount the Kings depend on Doughty is obvious. He plays over 41 per cent of their even-strength minutes, and just a hair under 50 per cent of their short-handed minutes.

Doughty starts most of his shifts in the defensive zone, deals with weaker than average teammates, and plays against an average level of competition.

The biggest on-ice impact Doughty has is on expected goals, where he leads this group, but his impact on actual goals and shot attempts have been nearly as strong.

Puck management is where Doughty truly excels compared to the rest of the league, boasting some of the lowest turnover rates of anyone, and the highest pass-success rates relative to his teammates of any player in the NHL in the defensive and neutral zones. There isn’t a single player in the league who is more dependable with passes in the neutral and defensive zones, he’s just on a whole other level.

Offensively Doughty isn’t a big standout in this group. He has produced 35 points this season, but his primary points at even strength aren’t that impressive, and he doesn’t produce a ton of scoring chances for his teammates compared to the other players here. Where he does excel, is puck movement around the offensive zone.

In the neutral zone Doughty is a very good defender, but without the puck he isn’t as aggressive as his reputation, winning pucks from opponents less often than his peer group, and blocking fewer passes in the defensive zone as well.

Doughty’s greatest strength is his transition play, there’s no defenceman better at it, and that ability automatically makes him a contender.

P.K. Subban

There probably hasn’t been enough focus on what Subban has accomplished this season. The biggest knock on him is that he isn’t as heavily relied upon as his peers in terms of ice time, playing the lowest percentage of his team’s ice time at even strength and on the power play of this group.

Subban also has a very stable partner situation, but the downside for him is that his partner is a huge drag on him. Subban has a 57.4 per cent Corsi without Alexei Emelin this season, but together they’re at just 49.2. Emelin without Subban this season is a startlingly awful 33 per cent Corsi, showing just how much he’s had to skate uphill this season.

With that struggling partner, Subban also starts almost 60 per cent of his shifts in the defensive zone, the toughest differential of the group, and he also faces the highest quality of competition, with the second-lowest quality of teammates. Those factors, despite his lower ice time, have Subban playing tougher minutes than any of his peers.

Considering how tough those minutes are, it’s a little surprising that Subban is able to maintain stellar on-ice performance impacts by all three measures relative to his teammates, especially with Roman Josi having an excellent season himself on another defence pairing.

Subban isn’t quite at the Doughty and Klingberg level in puck management this season, but he’s close, as those three are the only ones with positive relative rates in pass success and turnovers in every zone.

Subban’s production has been excellent, leading all defencemen in goals with 12, and he’s fourth in points – actually only one point behind Klingberg in primary points with 27 – but his actual involvement in offence at even strength is the lowest of the group. That could be because of the extra defensive assignments, but a bit of good fortune has helped Subban generate points at a rate higher than expected so far.

Defensively, Subban leads the NHL in won-puck battles in the defensive zone, and he has the sixth-highest puck-battle win rate in the league. He blocks a good number of passes in his defensive zone, but he could stand to be a bit more aggressive with his checks to remove possession from opponents.

While reputation would see Subban only in the Norris conversation for offensive play, it’s actually his puck-management skills and defensive ability that’s pushing play for the Predators this season; the offence has just been a bonus.

Alex Pietrangelo

Pietrangelo has been relied upon heavily in St. Louis this season, not only in terms of ice time, but he’s spent time with a bunch of random partners in a continuing effort to stabilize defence pairings in different game situations.

He plays the second-toughest competition of this group, but he also has the benefit of by far the highest quality of teammates, and despite that, Pietrangelo has a negative Corsi and expected-goals-for percentage relative to his teammates. His actual relative goals are extremely strong, but that’s due to a high PDO more than an extra level of control over scoring chances.

Pietrangelo is the strongest pass blocker in the group, and he generates tons of scoring chances for his teammates despite poor turnover and pass-success rates in the offensive zone, but his poor on-ice performance despite a high quality of teammates rules him out of the race for me at this point.

Erik Karlsson

The opposite of Pietrangelo’s season results has been Karlsson, who has been plagued by a ridiculous PDO of just 95, leading to a huge drop in point production and a goal differential that’s in the tank.

Despite that, no team relies on a defenceman as heavily at even strength as the Senators do with Karlsson. He plays a whopping 42 per cent of their minutes at 5-on-5, and his defence partner is essentially a random name generator, so seemingly every game he has to figure out how to play off a new one.

Karlsson gets a big offensive zone push on faceoffs, starting just 42 per cent of the time in the defensive zone, and his quality of competition is below average, but part of that is probably due to playing in the hilariously bad Atlantic Division. When it comes to quality of teammates, Karlsson is dealing with a whole new level of bad, and yet he has the strongest possession impact of any defenceman in the group, and his impact on expected goals is similarly excellent.

Lots of people have observed that Karlsson doesn’t look quite right this season after his foot injury last year, and while some of that is confirmation bias due to that horrendous PDO, Karlsson’s puck management has taken a severe dive this season in the neutral zone. Usually he can be relied upon to make far fewer mistakes than his teammates, but this year he’s been a bit of a mess both in turnovers and failed passes. Considering that owning the neutral zone is what Guy Boucher’s system is built around, this has created problems for Ottawa.

Offensively Karlsson is still the same player, but he’s had serious lack of finish at even strength, and his teammates aren’t finishing off his passes on the power play. Despite that, he’s only eight points off the league lead in primary points for defencemen, so not bad.

Defensively, Karlsson is far less involved in puck battles and blocked passing than he was last year, though he’s still checking at a really high rate.

Like Pietrangelo, at this stage I don’t think Karlsson is a super strong contender, but last season in early February I wrote about him not having a great season, and then he caught fire and by the end of the year, was robbed of the Norris in my opinion. With a player of the calibre of Karlsson, everything can change in 30 games.

Brent Burns

The reigning Norris winner started off this season completely unable to buy a goal, but has since caught fire, and since December is actually the NHL’s highest-scoring defenceman.

Burns gets over 70 per cent of his team’s power-play time, but he isn’t as relied upon at even strength (he gets about average top-pairing ice time), and doesn’t play much short-handed.

He has split his season pretty evenly paired with Joakim Ryan and Brenden Dillon, neither of whom are ideal top-pairing partners, but he’s had possession success with both of them.

He could use a better partner, but Burns plays butter-soft minutes for a No. 1 defenceman, getting a huge zone push to start 65 per cent of his faceoffs in the offensive zone, with high quality teammates, and below-league-average quality of competition.

Despite that, Burns actually has a negative expected-goals impact relative to his teammates, to go along with a brutal goal differential that is partially driven by poor percentages like Karlsson. But while Karlsson has a PDO of 95, Burns is 98.94, not so far off even that it could explain his teammates being over 24 per cent worse in goal differential when he’s on the ice.

While Burns is brilliant offensively, leading the league in scoring chances generated among defencemen with his machine-gun strategy from the point, puck management is not his forte; and he’s the messiest passer of this group.

Burns is an extremely aggressive checker, and blocks opposition passes in the defensive zone at an excellent rate, while winning battles at one of the highest rates in the league, but his poor impact on goals and puck management have him behind the top group at this stage.

Victor Hedman

The winner of the PHWA vote and a favourite right now, Hedman plays big minutes in every situation, and like Karlsson and Pietrangelo, is shuffled around with different partners to stabilize a defensive group in Tampa Bay that leaves a little to be desired.

Hedman gets a bit of a zone push with 56 per cent offensive zone starts, and he plays with a high quality of teammates against average opposition, likely impacted by playing in the Atlantic, though overall I wouldn’t say he plays very tough minutes for a top defender.

In on-ice performance, Hedman doesn’t stack up as highly as you would think, though he has a positive impact on all three metrics relative to his teammates.

What is a little surprising is that Hedman is actually below team average in pass-success rates in every zone, and worse than team average for turnovers in the defensive and neutral zones. Part of the reason for that could be the Lightning force him to do too much; only three defencemen in the league handle the puck more often than Hedman does, but even then, you would expect him to be above team average when that team also employs Dan Girardi and Braydon Coburn.

Offensively, only Burns creates more scoring chances for his teammates than Hedman does, and his passing is a big key to Tampa Bay’s dynamic offence at even strength and on the power play.

Without the puck Hedman truly excels, using his big frame and surprising quickness to aggressively step up on opponents with checks, block passes, and win puck battles. His presence in the neutral zone leads to a lot of denied zone entries, followed by neutral-zone puck recoveries.

Hedman is getting a little overrated due to the hype surrounding Tampa Bay right now, but he’s right in the thick of it.

Ranking the contenders

I’d lean ever so slightly towards Klingberg if I had a Norris vote. I’m not bothered much by his lack of time spent short-handed because his defensive impact at even strength has been phenomenal, and offensively he’s just a menace.

In second place I’d have a slight nod to Subban just over Doughty in third. Subban has eaten rougher minutes than any other defenceman this season when you factor in partner and competition affects, and he’s scoring more than Doughty as well.

In fourth I’d have Hedman, with Karlsson a slightly distant fifth, while Burns and Pietrangelo don’t quite make the ballot.