I did some posts a few days ago looking at famous defencemen and CorsiRel. I touched on three Washington Capitals defencemen: Karl Alzner, John Carlson and Mike Green. I’m going to reproduce the graphs here and my comments about them.
I know he was at Team Canada’s camp in Calgary last August; I don’t really see it.
Yeah, I don’t really get the Carlson popularity either. His Corsi falls in lockstep with Washington’s.
I’m going to have to look at some open play numbers for Green, Carlson and Alzner. Washington’s fall back to earth over the past few years has affected all of them, but Green still stands well above the Caps when he’s not on the ice, which isn’t true of the other two.
DCsportsfan85 had this to say:
Green is definitely the best puck moving defenseman for the caps and drives the play. He also is given more offensive zone starts and plays against significantly weaker competition than Alzner/Carlson.
Zone adj. possession metrics would paint a better picture, but that still doesn’t account for the quality of competition.
OK. I figured that I’d take a look at this. I identified 23 star forwards that I figured coaches would want to match their best defencemen against: E. Staal, Malkin, Bergeron, Kessel, Crosby, Nash, D. Sedin, Hall, Giroux, Pacioretty, Toews, J. Thornton, Kopitar, Toews, St. Louis, Zetterberg, Datsyuk, Tavares, Parise, Backes, Seguin, Ladd, Getzlaf and Doan. Murderer’s row.
For those of you who don’t follow the Capitals closely, Alzner/Carlson generally play as a pairing. Green then plays with someone else, most commonly Dmitry Orlov last year. So the Capitals played 824.2 5v5 minutes against those forwards last year. The defensive matchups break down like so.
So DCsportsfan85 has a point. The Caps definitely shelter Mike Green from the corrosive effects of the other team’s star forwards. They can’t do it completely but Carlson/Alzner are taking on a big chunk of the burden. So what would happen if we looked at the results put up by these seven pairings when there’s a star forward on the ice? Surely Carlson/Alzner will be better, right?
Well, it’s close enough that the difference is basically nothing but it turns out that the answer is “Not really” – it doesn’t seem to make much of a difference whether or not Green is out or Alzner/Carlson – the Capitals do about the same. I mentioned above that I wanted to look at some open play Corsi% stuff for these guys, so I decided to do that for star forwards.
Now that’s a little more interesting. All of a sudden, a large gap opens up between Green and Alzner/Carlson, with the Capitals doing much better when Green is on the ice than they do with the Alzner/Carlson pairing. It looks to me like the overall Corsi% looks much closer because of the Caps habit of putting Alzner/Carlson on the ice for offensive zone faceoffs against star forwards. Those are basically structural Corsi fests, so they look better than they actually are.
I’ve put together a breakdown of how the Caps used these guys for faceoffs against star forwards along with the faceoff percentages when they were on the ice against star forwards. It is, I think, telling:
The gist of it is this: Carlson/Alzner were on the ice for many, many more won OZ draws than Green and more OZ draws relative to their other draws. The Caps also had a horrible faceoff percentage with Green on the ice against a star forward for some reason. This explains why the overall Corsi% is closer than the open play Corsi%, I think – the numbers are misleading but to Green’s detriment.
This is a bit of interesting trend that’s emerged in two cases where I’ve taken a closer look at a defenceman who was being sheltered but put up better numbers than the people providing him shelter. In both cases, the guy being sheltered did better even if you just looked at star forwards and open play (Anton Stralman v. Ryan McDonagh was the other guy I looked at, although I didn’t write this part up).
Six points of Corsi, which is the edge that Green has over the Carlson/Alzner pairing in open play against stars (it’s also very similar to the overall edge, for what it’s worth) is a pretty significant margin. It’s difficult for me to imagine circumstances in which a guy could be bad enough when he is defending to overcome that difference.
Think of it in terms of 100 shots and assume that none of these guys affect on-ice S% (a fairly safe assumption). We’ll call the on-ice S% 8%. The Caps get outshot v. star forwards 52.3-47.7 with Green on the ice and 58.1 to 41.9 with Carlson/Alzner on the ice. At 8% shooting, that’s 3.816 goals on 47.7 shots when Green’s on the ice and 3.352 on 41.9 shots when Carlson/Alzner are out. Assume a league average save percentage behind Carlson/Alzner: .920. On 58.1 shots allowed, that’s 4.648 goals against, a difference -1.296 per 100 shots with star forwards on the ice.
Even if you think that defencemen have an impact on opposition shooting percentage, in order to post a worse goal difference against star forwards, the save percentage with Green on the ice would need to be .902 or worse. There simply aren’t defencemen who do that over any extended period of time. I am exceedingly skeptical that, whatever deficiencies he might have, Green’s true talent on-ice save percentage is anywhere near that low.
If you add it up, Green looks like he had the better season against the opposition’s best, although I haven’t taken into account linemates. It doesn’t really seem like it’s even that close though – I doubt the forwards that they’re paired with would make a significant difference. For what it’s worth, the three year on-ice save percentages for Mike Green (.920), Karl Alzner (.925) and John Carlson (.919) don’t really suggest a gap anywhere near big enough to negate Green’s big possession edge.
I have to think that we’re heading towards a bit of a re-thinking of how we understand defencemen. This isn’t really stats guys v. traditionalists – guys within the game are saying the same thing. Here’s Darryl Sutter:
“The game’s changed. They think there’s defending in today’s game. Nah, it’s how much you have the puck. Teams that play around in their own zone (say) they’re defending but they’re generally getting scored on or taking face-offs and they need a goalie to stand on his head if that’s the way they play.”
I think he’s right. But if he is right, one of the logical implications is that we need to reconsider the entire idea of a defensive defenceman at 5v5. If a defensive liability like Mike Green outperforms Washington’s shutdown pair against star forwards, doesn’t that kind of suggest that maybe we’re wrong when we think that you need stay-at-home defencemen, guys with grit and defensive skill? If what guys like Green and Stralman do works, shouldn’t teams want to get guys like that?Email Tyler Dellow at firstname.lastname@example.org