Hockey Outsider
Registered User
- Jan 16, 2005
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BM67 said:One big problem with most of these formulas is they reward goalies for stopping more shots. Facing fewer shots also brings with it it's own difficulties. Would you rather face a shot after making a flurry of saves a minute ago, or after not seeing a shot for 3-6 minutes?
It's true that there's no way to account for the psychological effects of making a lot of saves vs making fewer saves. However, the data shows over the history of the NHL, and especially this era, the number of shots a goalie faces has no effect on a goalie's ability to make saves.
BM67 said:That's a minor thing next to this "shot quality" thing. He says himself the data is wonky, then when you add in all the factors that aren't taken into account, it's value is very much in doubt. PP shots are of a "higher" quality, but what about shots just after a penalty expires? What kind of shot is it when a shot bounces off two legs and goes to a wide open player beside the net on the other side from the goalie? Is a player more likely to score if the goalie hasn't made a save in several minutes?
I agree that shot-quality neutral save percentage (SQN Sv%) doesn't (and can't) tell you everything. (The examples of potential problems you mentioned were legitimate, though probably immaterial over the course of a season). But as long as it's an improvement over save percentage, it's more valuable and should be used. Since SQN SV% can tell us things like which teams usually give up shots from far away, which give up more rebounds, which give up more wraparounds, etc., it tells us more than normal save percentage does.
Not sure if you're aware, but I didn't invent shot quality neutral save percentage, Alan Ryder did. So you may want to ask those questions to him.
BM67 said:Also why if you're going shot by shot, don't you break it down goalie by goalie rather than just lumping them by team?
If Mr. Ryder is calculating the data based on the source I think he's using, there are no records of the goalies involved. Going back and manually determining which goalie was in net for each shot (a total of roughly 68,000 shots) would be a phenomenally time-consuming effort. Though I fully agree with you in principle: the data quality would be improved if it was broken down on a goalie-by-goalie basis.