I did fully intend to pursue research VERY similar to what Alan Ryder did; he simply beat me to it. And did a very nice job, too.
As for how strong a correlation coefficient is, there is no "right answer". Professional statisticians generally consider a coefficient of plus or minus 0.7 to be very strong, possibly indicating a causational relationship. As always, remember that correlation does not necessarily imply causation. Another way to look at it is the R-squared stat. I believe (and I'd have to look it up) that R-squared is simply the coefficient of correlation, squared. R-squared represents the approximate percentage of variation explained by the variable in question. So a correlation coefficient of .70 would mean and R-squared of .49, meaning that 49% of the variation of one number is explained by the other. The lower you go, the less it is. A coefficient of .20 would mean only 4% of the variation is explained. Again, I don't have my textbook handy, but I think that's right.
As for my earlier work on Perseverance, perhaps I was a bit brasher in those days, and that was indeed a long time ago, in terms of my "career" as a hockey analyst. I was just starting out as a dedicated hockey analyst, whereas now it's just something I do. Would I have written the same words today? Not likely. But the past is the past.
As for "Joe Fan", one of the worst things you can do is "dumb down" what you're doing. Teachers should not reduce their lessons to the lowest denominator, they should bring their students up to an appropriate level of understanding. Not that I'm saying K&R dumbed down their work, they certainly didn't. Most of what is written in the two Compendiums is quite brilliant, including the statistical stuff. Some of it is just incomplete. They assumed that Perseverance was an improvement on save percentage without testing it. They made a slight mathematical boo-boo in their adjusted plus-minus calculations. They also should have compiled more than one season's worth of crucial scoring numbers to test its validity as an individual stat. That's about it.
Just had another look myself. The words "patently ridiculous", which you took out of context, were used because it is something K&R themselves wrote. It was a little bit of irony.
And seriously, when was the last time you said "I provisionally conclude that this is not valid"? My website is certainly not an academic journal, and even articles in academic journals don't always use language like that. Obviously, it was provisional, since I have now stated there may be some validity, based on new evidence.
I just re-cracked open my K&R Compendium (the latest one) and was reading about Perserverence. It seems obvious to me that there would be a relationship between number of shots and save percentage, and given the above post it seems that there is one.
What I'd like to know is why K&R came up with .6 ( I Think ) as the number to factor into #shots taken. It seems arbitrary to me. I'd like to see them use a number that comes out of research.
