Hi friends! I made some pictures because I wanted to visualize some things.
We're at a point in the season now where the team has played more games in a zone defense system than it did man to man. Things have certainly appeared to improve, so I put together a rolling graph to see whether our eyes' perspective on possession is accurate. This is rolling 5v5 Corsi Differential for the season to date.
The black line is the Toronto game, which was when the team switched schemes. Those aren't real trendlines, I drew them on in MS Paint from first point of the set to last point, but they certainly help to show the difference in possession numbers. So was our eye test accurate? This time, yes, it was. The change to the defense is doing a better job of limiting shot attempts.
I also wanted to present individual players in a way to basically ask, why do we focus on the guys that we do? These numbers are raw; I've not adjusted them for usage or score effects.
First up let's see where the big minus-more-than-250 has come from, individually. This is Corsi differential visualized as raw CA vs. CF, among players who've played enough minutes that I excluded Stollery and Vincour. It's in order from best differential to worst.
Gabriel Landeskog has the only positive differential on the team. That's good for him, but bad for everyone else who cares about this team.
The reason I wanted to visualize it this way is to show who is having the biggest real impact both offensively and defensively. Jan Hejda and Erik Johnson, for example, have been on ice for the most shot attempts both for and against. That's probably because of their ice time, but it makes their differential matter the most. Someone with a spread like Nick Holden's is probably getting too much ice time, by contrast. Also, we all cry about Cody McLeod a lot recently, which is fine when he's putting his team on the penalty kill, but he still has exactly the same possession impact as a guy who's missed half the season with injuries (Brad Stuart).
The raw size of those bars are more impacted by ice time than anything else, though, so how does it look when we control this for ice time? Here's your Corsi/60 differentials. so far.
Brad Stuart's differential is tanked quite a lot because I'm pretty sure his injury happened at the same time as the system swap.The team wasn't working when it was running a man system, and Stuart's bars here show the difference pretty starkly.
So this chart is a little harder to look at, at least for me, because the differences aren't quite as obvious. One thing that does pop out is that there's not as huge an amount of differences between players in terms of attempts against. From the least (Ryan O'Reilly) to the most (Stuart), the difference is 15 shot attempts per 60. When we look at attempts for, from the most (Landeskog) to the least (Marc-Andre Cliche), the difference is more like 25 shot attempts per 60. But even Cliche, third-worst differential, is on the ice for fewer shot attempts against per 60 than Nathan MacKinnon, whose differential is the second-best!
What this says to me is everyone is anchored by the same shitty team defense, while guys' talent is more coming out in terms of creating attempts the other way. I think that's weird but I don't know if it actually is or not. In the future I'm going to use data adjusted for score, and possibly usage, effects to see if it still stands out. (That will lift guys like Iginla and Duchene, while driving guys like O'Reilly downward.)