Quote:
Originally Posted by Taco MacArthur
Good question. If we assume that shots on net follow a binomial distribution (admittedly a stretch), then as the number of shots faced increases, the distribution can be approximated by a normal distribution.
At that point, and with a zscore, it's just a matter of measuring the area to the right (in the case of a positive zscore) or to the left (in the case of a negative zscore).
For instance, consider a goaltender with a zscore of 1.48 (since that's an image that I was able to swipe online ):
There is 6.94% of the curve to the left of the goaltender's performance, so we would expect a goaltender to do as poorly as he did (or worse) 6.94% of the time. So it would happen about every 14.4 seasons (since 1/6.94% = 14.4).
Does that make sense? Once we assume a binomial distribution (which isn't perfect, but it's not horrible), then it's just probability theory.

Makes perfect sense. Thank you so much for taking the time to answer me!