Friday, January 18, 2019
Introduction to WAR, part 3 of n
The series concludes, and now I will provide constructive criticism. (Parts 1 and 2 are here.)
As I noted, I got a sneak peek, and I sent the twins my comments. The first thing to jump out as being problematic is this:
If it didn't jump out at you at first reading, then it would once you look at player results. The way I break out WAR is about 60% forwards, 30% defenseman, 10% goalies. You can argue goalies should be anywhere from 8% to 12%. If you look at how much goalies get paid, they get close to 10% of the payroll. There's many ways you can try to look at it, but everytime I do, I end up around 10%. So, anything that is not 10% is highly suspect, and almost certainly wrong. I went after Hockey Reference on this very issue a decade ago because they were way overboard on the Goalie Win Shares.
The above chart suggests goalies are a bit above 130 WAR for a bit under 600 WAR, or over 22%, double what I say. This by itself is enough to doom the system. But fear not, because the guys are very engaging and this is their opening salvo. I'm sure once the community becomes more involved, the ~10% will become standard.
The other one is the split between F and D. I use 2:1 split, and you can maybe argue for 3:2 split, but really it'll be somewhere between the two. Their split is about 2.2 to 1. Not egregious and if not for the goalie split, not really worth bringing up. But if we're going to fix the goalie thing, then we should talk about the F/D split.
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The other thing is the goals per win conversion. I've shown empirically and theoretically what it should be. Their goals per win is simply too low. It's all fine and well to create a theoretical model. But if the model doesn't match reality, it's not really a model. In the end, you have to represent reality to some degree, and this shorthand gets us there:
goals/win = goals/60min + 2.75
The NHL, with overtime, and 3-on-3, and shootouts, and "playing for the tie in regulation" provides us with all kinds of things to think about. This is why the theoretical is always going to be limited if the model doesn't account for everything. Their model is close to around +2.50 instead of the +2.75 I am using.
This again should be an easy one for the hockey community to figure out.
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The rest of what I will say is really not a disagreement, so much as an explanation. I'll put that in the comments as the mood strikes me.
It's terrific stuff overall, and that I've said as little as I have given they have written so much is really testament to how seriously and thorough they were. This provides a terrific benchmark and reference point for discussion.
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