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With Apologies to The Weakerthans…I hate “Shot Quality”

The notion of "Shot Quality" is hardly a new one. Alan Ryder probably published his first analysis of it ten years ago and he published his recall of it – because it's hopelessly overwhelmed by arena bias – over four years ago. So what have we learned in ten years?

Alan’s initial observation – the likelihood of a shot going in vs a shooter’s distance from the net – is a good one. As are adjustments for shot type and rebounds. But it turned out there wasn’t much else there. Why? The indispensable JLikens explained why – he put an upper bound on what we could hope to learn from “shot quality” and showed that save percentage was dominated by luck. The similarly indispensable Vic Ferrari coined the stat “PDO” – simply the sum of shooting percentage and save percentage – and showed that it was almost entirely luck. Vic also showed that individual shooting percentage also regressed very heavily toward a player’s career averages. An exhaustive search of players whose shooting percentage vastly exceeded their expected shooting percentage given where they shot from turned up one winner: Ilya Kovalchuk…Who proceeded to shoot horribly for the worst-shooting team in recent memory last season.

We started from a truth ("shot quality" does indeed vary on individual shots) and essentially never used that idea to gain any broader insights about individual players or teams. Which team will have the highest even-strength shooting percentage this year? Nobody knows…Or at least nobody is willing to bet on it. What about goaltender talent? Have we come up with a better predictive model for goalie performance because we're able to remove the impact of the defense from overall results?

Now I’m not rejecting finishing and defensive/goaltending talent – they all exist. But I’d like to move past shot quality as such a frequent focus of analysis because I don’t think it’s going to return much for all of the effort. (Virtually no one entered the shot quality prize competition on this site, so maybe people aren’t as interested in it as I think.) If the Edmonton Oilers called you up and offered you their general manager job, what would be your first piece of advice? Would you tell them to chase after players who’ve had high on-ice shooting percentages over the last few years or who’ve exceeded their expected shooting percentages given their shot locations?

I think you know the answer. Even though we're nowhere near the level of confidence that baseball analysts have come to, hockey analysis has turned up value in a number of places. There are dozens of things an NHL team should chase before they start looking for finishing talent.

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