[h=1]Handicapping the Norris race[/h][h=3]Following Giordano's injury, it's wide open; here are the top candidates[/h]
By Rob Vollman | ESPN Insider
Hockey analytics pioneer Rob Vollman is ESPN Insider's armchair GM this season, exploring how modern statistics can inform front-office decisions.
A torn bicep has knocked Mark Giordano out of Calgary's lineup, and also broke this year's Norris Trophy race wide open. Drew Doughty, Shea Weber and Kris Letang headline a long list of defensemen who could make a serious case for themselves if they catch fire down the stretch. Is there a clear front-runner?
That's up to the members of the Professional Hockey Writers Association (PHWA) to decide. Every year, the PHWA voters award the Norris to the defenseman with "the greatest all-round ability," theoretically ignoring how valuable he is to the team or how much overall opportunity he may have had to contribute.
Unfortunately, nobody can watch every minute of all 82 games for all 30 teams to make a completely fair assessment of every defenseman, especially local beat reporters who are lucky to catch some teams more than a few times per season. Even when evaluating the local team's players, sometimes that journalist's perspective can be influenced by other factors, such as a defenseman's personal reputation or his play in previous seasons. In short, there are several reasons why a voter may want to double-check his or her subjective opinion with a look at the cold, hard numbers.
Evaluating defensemen using hockey analytics isn't easy, but we have come a long way over the years. Furthermore, the same statistics that serve as a sober second thought for PHWA voters are also useful to NHL front offices contemplating trades or free agency, and therefore useful to fans to help understand their moves. Norris Trophy races will come and go, but the process for evaluating defensemen is both fascinating and timeless.
Here's a look at which players are currently in the mix heading into the final stretch of the season:
Leading scorers
Scoring is very important to PHWA voters. The leading blue-line scorer has won the Norris in two of the past three seasons, with Duncan Keith's second-place finish last season close behind. Whichever of the leading candidates secures a few extra points down the stretch will have a huge advantage.
Ottawa's Erik Karlsson was the runaway winner of the scoring race in two of the past three seasons, but it's a much tighter pack in 2014-15. Letang just passed him atop the leaderboard with 51 points, San Jose's Brent Burns and Montreal's P.K. Subban are just one point behind, followed by Nashville's Roman Josi with 47 and Washington's John Carlson with 46. Beyond those six, there are eight more uninjured defensemen who have at least 40 points. The scoring race is almost anyone's to win.
It seems unfair that scoring is that important to the voters, especially since opportunity can have as much to do with a player's scoring totals as his own abilities -- this is especially true for defensemen. For example, the power play has a lot to do with both Karlsson's and Letang's scoring this season. At even strength, several defensemen are actually ahead of those two, including Subban and Carlson. They're each three points up on Burns and Josi, with Colorado's Tyson Barrie trailing those latter two by a single point. With the same power-play opportunities, any of these five players could be outscoring Karlsson and Letang.
And what about the effect of ice time on scoring? The loss of Willie Mitchell to free agency and Slava Voynov for an off-ice incident has thrust a lot of extra minutes on Doughty. The Kings' top defenseman has already logged more than 1,350 minutes at even strength, while Barrie and Letang have barely cleared 1,000. With just two more points, Doughty will have his highest-scoring season since he was a 20-year-old Norris finalist in 2009-10.
The ice-time advantage is even more prominent with the man advantage, where Karlsson has already worked more than 280 minutes. That's almost an hour more than minute-munchers like Ryan Suter and Doughty, and Carlson is barely above 100 minutes.
What would each defenseman's scoring look like if they all had the same ice time? The following chart adjusts every player's scoring totals to his approximate average of 1,200 minutes at even strength in blue, and 200 with the man advantage in red. I've included all of the league's leading scorers, along with four other prominent Norris contenders: Keith, Doughty, Suter and Calgary's T.J. Brodie:
Rob Vollman
Once adjusted for ice time, Carlson appears to be the runaway scoring leader, but he gets to play with prolific scorers like Alexander Ovechkin and Nicklas Backstrom. And Letang, who ranks second, gets to work an equally deadly power play with Sidney Crosby and Evgeni Malkin. So it's not just how many minutes a defenseman gets that can influence his scoring -- whom he's playing those minutes with is a big factor.
That's why I've prepared the following chart, which uses data from Behind the Net to illustrate the scoring advantage some of these players enjoy. For example, playing with Ovechkin and Backstrom means that Washington scores on more than 10 percent of its shots at even strength, and 14 percent on the power play, whenever Carlson is on the ice. That gives him and comparable players like Burns, Letang, Brodie and Subban a significant advantage over everybody else.
Rob Vollman
Again, once we adjust for playing time, Carlson may be the runaway leader in scoring, but that's partly because of his incredible teammates. Of the seven players in a tight pack behind him, only the scoring successes of Karlsson, Weber and Josi aren't being boosted by high shooting percentages. Is there a strong Norris case for one of these three defensemen? Not necessarily, if we're keeping the "greatest all-round ability" qualifier in place.
Player usage
The following player usage chart helps explain why the Norris case isn't stronger for Karlsson, despite his potentially becoming the NHL's leading scorer among defensemen for the third time in four seasons. This chart places each player's performance in the right context with regard to the average quality of his competition (on the vertical axis), the zones in which he plays (on the horizontal axis) and how well the team does possession-wise (with the sized, shaded circles). Karlsson may get a lot of playing time, but it's not against the top lines, and he has a slight offensive-zone tilt.
Rob Vollman
The Norris Trophy is awarded to the defenseman with the best abilities in all facets of the game, and Karlsson's usage numbers suggest that he's more of an offensive specialist. In fact, Karlsson and Barrie are the only two defensemen on this chart who don't work a regular penalty-killing shift; on the other end of the spectrum, Carlson ranks 10th among NHL defenders with more than three minutes of short-handed ice time per game.
As for Nashville's Weber and Josi, the white circles indicate that they join Carlson as the only defensemen under consideration who actually put their teams at a shot-based disadvantage. That is, the Predators actually have a larger share of the team's attempted shots when those two are on the bench, which generally means that they have the puck more frequently, too. Their fans could argue that this is because Weber and Josi play the tough minutes against top opponents in the defensive zone, but even alternate forms of this statistic that adjust for playing conditions -- such as Steve Burtch's dCorsi -- suggest that they are not good possession-driving players no matter where or against whom they play.
In the end, we're left with one-way offensive players like Karlsson and Barrie; players who are failing to drive possession, like Josi, Weber and Carlson; and a handful of players without obvious weaknesses but who are otherwise not leading the pack in any particular regard. Is there anyone else we've overlooked who might stand out?
Dark horses
Combing the league for any remaining all-around defensemen who play in both zones, take on top opponents, kill penalties, drive possession and score at both even strength and the man advantage without getting boosted by their teammates yields just three more players: Carolina's Justin Faulk, Montreal's Andrei Markov and Boston's Dougie Hamilton.
There are several defensemen who are superior in one regard or another, but given that the Norris is awarded to the defender with the best all-around abilities, it's important that all three of these defensemen fit nicely on all three charts. While it is unfortunately doubtful that any of these three will actually receive some Norris consideration, they still serve as excellent examples of how hockey analytics can be used not only as a sober second thought on the mainstream's contenders, but also to find players who may be deserving of a closer look.
Looking ahead
Giordano embodied all the attributes of a Norris Trophy winner. He was leading the scoring race, took on top competition in both zones, excelled in all manpower situations and helped drive the team's possession. There really isn't a single candidate left who compares favorably in all four areas.
That's why the Norris race is wide open. Even if Karlsson wins the scoring race, he may still be viewed by voters as a more one-dimensional offensive weapon. Likewise, Weber is a more complete two-way player, but his team struggles, possession-wise, when he's on the ice. Carlson is an interesting dark horse, but both he and Letang may be seen more as passengers on teams led by star forwards. That leaves more traditional options like Doughty, Keith and Subban, none of whom has really found a way to separate himself from the pack.
The race is so tight that even a short hot streak is all it might take for any one of a dozen players to jump in front in the Norris race. There are a lot of defensemen to watch down the stretch, and now we've got the tools to evaluate them.
By Rob Vollman | ESPN Insider
Hockey analytics pioneer Rob Vollman is ESPN Insider's armchair GM this season, exploring how modern statistics can inform front-office decisions.
A torn bicep has knocked Mark Giordano out of Calgary's lineup, and also broke this year's Norris Trophy race wide open. Drew Doughty, Shea Weber and Kris Letang headline a long list of defensemen who could make a serious case for themselves if they catch fire down the stretch. Is there a clear front-runner?
That's up to the members of the Professional Hockey Writers Association (PHWA) to decide. Every year, the PHWA voters award the Norris to the defenseman with "the greatest all-round ability," theoretically ignoring how valuable he is to the team or how much overall opportunity he may have had to contribute.
Unfortunately, nobody can watch every minute of all 82 games for all 30 teams to make a completely fair assessment of every defenseman, especially local beat reporters who are lucky to catch some teams more than a few times per season. Even when evaluating the local team's players, sometimes that journalist's perspective can be influenced by other factors, such as a defenseman's personal reputation or his play in previous seasons. In short, there are several reasons why a voter may want to double-check his or her subjective opinion with a look at the cold, hard numbers.
Evaluating defensemen using hockey analytics isn't easy, but we have come a long way over the years. Furthermore, the same statistics that serve as a sober second thought for PHWA voters are also useful to NHL front offices contemplating trades or free agency, and therefore useful to fans to help understand their moves. Norris Trophy races will come and go, but the process for evaluating defensemen is both fascinating and timeless.
Here's a look at which players are currently in the mix heading into the final stretch of the season:
Leading scorers
Scoring is very important to PHWA voters. The leading blue-line scorer has won the Norris in two of the past three seasons, with Duncan Keith's second-place finish last season close behind. Whichever of the leading candidates secures a few extra points down the stretch will have a huge advantage.
Ottawa's Erik Karlsson was the runaway winner of the scoring race in two of the past three seasons, but it's a much tighter pack in 2014-15. Letang just passed him atop the leaderboard with 51 points, San Jose's Brent Burns and Montreal's P.K. Subban are just one point behind, followed by Nashville's Roman Josi with 47 and Washington's John Carlson with 46. Beyond those six, there are eight more uninjured defensemen who have at least 40 points. The scoring race is almost anyone's to win.
It seems unfair that scoring is that important to the voters, especially since opportunity can have as much to do with a player's scoring totals as his own abilities -- this is especially true for defensemen. For example, the power play has a lot to do with both Karlsson's and Letang's scoring this season. At even strength, several defensemen are actually ahead of those two, including Subban and Carlson. They're each three points up on Burns and Josi, with Colorado's Tyson Barrie trailing those latter two by a single point. With the same power-play opportunities, any of these five players could be outscoring Karlsson and Letang.
And what about the effect of ice time on scoring? The loss of Willie Mitchell to free agency and Slava Voynov for an off-ice incident has thrust a lot of extra minutes on Doughty. The Kings' top defenseman has already logged more than 1,350 minutes at even strength, while Barrie and Letang have barely cleared 1,000. With just two more points, Doughty will have his highest-scoring season since he was a 20-year-old Norris finalist in 2009-10.
The ice-time advantage is even more prominent with the man advantage, where Karlsson has already worked more than 280 minutes. That's almost an hour more than minute-munchers like Ryan Suter and Doughty, and Carlson is barely above 100 minutes.
What would each defenseman's scoring look like if they all had the same ice time? The following chart adjusts every player's scoring totals to his approximate average of 1,200 minutes at even strength in blue, and 200 with the man advantage in red. I've included all of the league's leading scorers, along with four other prominent Norris contenders: Keith, Doughty, Suter and Calgary's T.J. Brodie:
Rob Vollman
Once adjusted for ice time, Carlson appears to be the runaway scoring leader, but he gets to play with prolific scorers like Alexander Ovechkin and Nicklas Backstrom. And Letang, who ranks second, gets to work an equally deadly power play with Sidney Crosby and Evgeni Malkin. So it's not just how many minutes a defenseman gets that can influence his scoring -- whom he's playing those minutes with is a big factor.
That's why I've prepared the following chart, which uses data from Behind the Net to illustrate the scoring advantage some of these players enjoy. For example, playing with Ovechkin and Backstrom means that Washington scores on more than 10 percent of its shots at even strength, and 14 percent on the power play, whenever Carlson is on the ice. That gives him and comparable players like Burns, Letang, Brodie and Subban a significant advantage over everybody else.
Rob Vollman
Again, once we adjust for playing time, Carlson may be the runaway leader in scoring, but that's partly because of his incredible teammates. Of the seven players in a tight pack behind him, only the scoring successes of Karlsson, Weber and Josi aren't being boosted by high shooting percentages. Is there a strong Norris case for one of these three defensemen? Not necessarily, if we're keeping the "greatest all-round ability" qualifier in place.
Player usage
The following player usage chart helps explain why the Norris case isn't stronger for Karlsson, despite his potentially becoming the NHL's leading scorer among defensemen for the third time in four seasons. This chart places each player's performance in the right context with regard to the average quality of his competition (on the vertical axis), the zones in which he plays (on the horizontal axis) and how well the team does possession-wise (with the sized, shaded circles). Karlsson may get a lot of playing time, but it's not against the top lines, and he has a slight offensive-zone tilt.
Rob Vollman
The Norris Trophy is awarded to the defenseman with the best abilities in all facets of the game, and Karlsson's usage numbers suggest that he's more of an offensive specialist. In fact, Karlsson and Barrie are the only two defensemen on this chart who don't work a regular penalty-killing shift; on the other end of the spectrum, Carlson ranks 10th among NHL defenders with more than three minutes of short-handed ice time per game.
As for Nashville's Weber and Josi, the white circles indicate that they join Carlson as the only defensemen under consideration who actually put their teams at a shot-based disadvantage. That is, the Predators actually have a larger share of the team's attempted shots when those two are on the bench, which generally means that they have the puck more frequently, too. Their fans could argue that this is because Weber and Josi play the tough minutes against top opponents in the defensive zone, but even alternate forms of this statistic that adjust for playing conditions -- such as Steve Burtch's dCorsi -- suggest that they are not good possession-driving players no matter where or against whom they play.
In the end, we're left with one-way offensive players like Karlsson and Barrie; players who are failing to drive possession, like Josi, Weber and Carlson; and a handful of players without obvious weaknesses but who are otherwise not leading the pack in any particular regard. Is there anyone else we've overlooked who might stand out?
Dark horses
Combing the league for any remaining all-around defensemen who play in both zones, take on top opponents, kill penalties, drive possession and score at both even strength and the man advantage without getting boosted by their teammates yields just three more players: Carolina's Justin Faulk, Montreal's Andrei Markov and Boston's Dougie Hamilton.
There are several defensemen who are superior in one regard or another, but given that the Norris is awarded to the defender with the best all-around abilities, it's important that all three of these defensemen fit nicely on all three charts. While it is unfortunately doubtful that any of these three will actually receive some Norris consideration, they still serve as excellent examples of how hockey analytics can be used not only as a sober second thought on the mainstream's contenders, but also to find players who may be deserving of a closer look.
Looking ahead
Giordano embodied all the attributes of a Norris Trophy winner. He was leading the scoring race, took on top competition in both zones, excelled in all manpower situations and helped drive the team's possession. There really isn't a single candidate left who compares favorably in all four areas.
That's why the Norris race is wide open. Even if Karlsson wins the scoring race, he may still be viewed by voters as a more one-dimensional offensive weapon. Likewise, Weber is a more complete two-way player, but his team struggles, possession-wise, when he's on the ice. Carlson is an interesting dark horse, but both he and Letang may be seen more as passengers on teams led by star forwards. That leaves more traditional options like Doughty, Keith and Subban, none of whom has really found a way to separate himself from the pack.
The race is so tight that even a short hot streak is all it might take for any one of a dozen players to jump in front in the Norris race. There are a lot of defensemen to watch down the stretch, and now we've got the tools to evaluate them.
