I don't want to hijack the thread, especially since this has been discussed before but I should just give a few comments.
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Originally Posted by seventieslord
You are overdoing it. Also breaking it down into tiny onegame samples is probably less statistically efficient than just looking at the whole season. If you don't feel like it, I will do it later, and I will even take out PPs to even the playing field because there is a known correllation between facing more pp shots and having a lower sv%.

Efficiency is not a problem here. I did not break it down to onegame samples. What I did was to aggregate the save percentage for each number of shots in a game. For instance, a goalie faced 20 shots 36 times with an average save percentage of 87.78.
You are right that it would be important to take special team effects into account. However, as you say, we would expect the bias to go in a downward direction. That is, a goalie that is often on the penalty kill will face more shots in total that are also of higher quality.
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Those are extremely poor sample sizes. Save your smileys for if the resjlts agree with you when alanlyzed properly.

What do you mean poor sample sizes?
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Was the original claim of a SOG  SV% relationship about the game level or the season level? Because it's definitely true on the game level. Matnor's numbers prove that without a doubt.
On the other hand, the relationship is much weaker on a season level, and might be nonexistent after correcting for arena recording bias.

Yes, my claim was only on a gamebygame basis. It is theoretically possible that the relationship disappears when aggregating. For instance, take Brodeur as an example. It could be the case that on a gamebygame basis he has better save percentage when he faces more shots. On the other hand, he has historically played on a defensiveminded team which may have lowered both the shot quality and the number of shots he faced. So, when comparing him to another goalie he would have both better save percentage and having faced fewer shots. In that way, the aggregate effect could be different.
I tested this using aggregate data (save percentage by season and goalie) from 83/84 to 07/08 for goalies who played at least 40 games and regressed the save percentage on the average number of shots per game faced by each goalie and season. And the result is statistically significant on any conventional significance level. On average, each extra shot per game results in a higher save percentage by almost 0.1 percentage point. That is around half the effect found on the individual level (where an extra shot per game leads to a higher save percentage with around 0.2 percentage point).
To visualize the result I split the goalies into five groups for each season sorted by the number of shots they faced on average. I then aggregated the save percentage for each group and this is the result:
Group  SA/GP  Save% 
1  25.3  89.85% 
2  27.28  89.96% 
3  28.60  90.07% 
4  30.17  90.05% 
5  32.45  90.27% 
As can be seen, the difference in save percentage between the fifth of the goalies with the least shots against and the fifth of the goalies with the most shots against are around 0.4 percentage points. So, I'm not argue that it's a big difference but the effect is there.
You are right that arenarecording bias could confound the result. To test that one would have to aggregate gamebygame data after removing the arena effect. Unfortunately, it would require some data work that I'm not sure I have the time for. I might check that later (or you might want to do it
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The correllation between shots against per minute and total sv% is 0.286. Weak.

I guess it was my fault for using the term correlation. A correlation coefficient (or Rsquared for that matter) is only useful if my claim would have been that the number of shots a goalie faces is the dominant determinant of save percentage. Of course that is not my point, a goalie's skill is much more important. That being said, it may still be worth taking into account. Specifically, two important questions need to be adressed. First, is the effect statistically significant (and it is, though we may worry about confounding factors)? Second, is the effect is of significant size? That is, is it important to take into account that a goalie who faces one additional shot have a lower save percentage with 0.1 percentage point? If the answer is yes to both these questions than the fact that the correlation coefficient is small is pointless.
All in all, sorry for derailing the thread. I think this is interesting and is something that is worth studying more. My conclusion is that there is a clear positive correlation on a gamebygame basis and that it looks as if this is also true on a goalieandseason level though there are a number of unresolved issues that needs to be addressed. I guess my main point is that I sometimes here arguments such that "not only did he have an outstanding save percentage, he had it while facing the most shots in the league" and I think that is a problematic statement.