Statistics over a year will do a good job of stamping out random luck.
Yes and no. I mean, we see guys with very random shooting / save percentages every year and it's not a small amount, but it is a small amount relative to the total league players lol. Obviously more guys would be in line with their averages, so it's not the norm or anything, but someone having a very random outlier percentage season isn't atypical or anything.
We had bad goalies. Getting that out of the way before I get accused of not believing it. But you can't think what happens in front of a goalie doesn't affect a goalie outside just the pure number of shots.
Historically, Graves has had a better on ice save percentage than Slavin. Do we think that's because Slavin is a worse even strength defender than Graves? One thing I do agree with Jim about is that there are a lot of variables which make these these stats tricky. Level of competition, teammates. This 100% matters.
But there's nothing in Grave's profile that really indicates he should have had a .933 save percentage at even strength last year. He had 52 expected goals against and only gave up 38. He was basically 50/50 in high danger chances for and against.
According to natural stat trick, there were 221 high danger chances with him on the ice at 1139 ES minutes (16.27 ES minutes per game). Nemec was at 201 in 1062 (17.7 ES minutes per game). So graves gave up .194 high danger chances per minute while Nemec gave up .189 high danger chances per minute. One guy had a .933 save percentage, the other had .891.
Now, it's important to note that these stats aren't the end all be all. There are some flaws in things like how the nature of a high danger chance is calculated. Not all high danger chances are equal either. But they are at least a guiding star. Everything else is "eye test". They are the best we have. And there's nothing there that tells us that one should realistically have a .933 and the other an .891.
I absolutely think what happens in front of a goalie matters. That's how Adin Hill wins a stanley cup.