Figuring out goalies has long been in the domain of the crystal ball. Trying to work out which one will make it to the NHL and which will end up with psychological problems wondering where it has all gone wrong. As I am a goalie I thought I would summon up what is left of my brain after drinking the Jordan Eberle Kool-Aid and solve this problem.
Montreal Canadiens Washed Up Goalie Commercial (via HockeyFans101)
What We Already Know
Save percentage which every goalie is judged on is partially a team statistic. I am not a great goalie, part of the reason I am not in the NHL. I would say I am not even a good goalie, a bigger part of the reason I am not in the NHL. Nonetheless I enjoy the thrill of being nearly concussed as blistering slapshot rings off of my helmet. However, I have noticed that my save percentage yo-yo's a bit with how well we do as a team, when we win the league it is often pretty good, and when we nearly get demoted it is pretty bad.
I think to a degree this is why goalies are so hard to figure out. The team in front of them has a lot to do with their boxcars. There is also an inordinate amount of loyalty to goalies, if you want to move up a division as a rec hockey goalie you need some guy in the division ahead of you to die or move to Toronto. The same is largely true in the NHL, look no further than the fact the Khabibulin still has employment. Or simply the way that coaches deploy their goalies.
The other part is psychology, I had a pre-game all you can eat buffet about 4 hours before my game, thought it would be alright. It wasn't, I felt fat. I didn't play well. On another occasion I wasn't happy with my skate cut, I just didn't feel comfortable with how they moved, I didn't play well. I had a game where I let in 4 goals in the first period to team that was miles better than us, I got angry at myself, I played the best 2 period(43 Saves) of my life, and we lost 4 to 1. The point is psychology had a huge bearing on how I played probably why I am not in the AHL. At higher levels goalies keep it together allot better, although they do snap from time to time.
Preamble to the Solution
When it comes to advanced statistics for goalies there isn't much out there that provide any clues, particularly at the lower levels.
It is proven statistically that the further out a shot comes from the easier it is to save. I can stop shots from the blueline all day every day if there is a clear line of sight. Ask any goalie and they will tell you a shot from the point even from a guy like fastest shot winner Al Iafrate isn't a big deal. It gets a bit dicier when you add traffic.
You take that same shot or even a slower velocity shot and move it into the slot and it is infinitely harder to stop.
You add movement and it is even harder to stop.
Then you have shot location, every goalie has weaknesses, and some are more obvious than others. I have a hell of a time with a right handed shooter doing a simple 3 step deke sliding the puck behind my left leg, probably why I have played professionally anywhere, and never went further than rec hockey.
I am coming to peace with my deficiencies. However, with all these things in mind I think I may have...
A Possible Solution
Save percentage should be divided into a 3 part formula.
Part 1 - Shot Distance compared to expected save percentage from that distance. For instance defencemen have a shooting percentage of just over 4 percent and presuming that most of those shots come from the blueline that would mean an expected save percentage of .95 odd. This would mean that a goalie who's team constantly allows shots from in tight isn't getting punished in save percentage versus a goalie who's team is only allowing outside shots.
Part 2 - Shot Location In The Net. The NHL has some interesting statistics on this, NHL goalies are staggeringly good one of the holes (I can't remember but I think it was low glove side), something like 3% of goals scored here. This would be factored in as above related to an expected percentage.
Part 3 - Movement/Traffic. Again relate these back to an expect percentage.
Then you would take these numbers to make a REL Sv Pct.
From these numbers on a game by game basis you would see how often a goalie exceeds the expected REL Sv Pct. Thereby enabling you to develop a Consistency Percentage.
I think by comparing these two stats with the progression of NHL goalies you would be able to come up with a very accurate goalie prediction tool.
The issue is that these statistics are simply not gathered at most levels, and where they are gathered they are not very accurate. For instance the NHL does record shot distance on every shot, but in the few games where it has been intensively analysed it was found to be very inaccurate.
So perhaps this is a dream. But if I was an NHL GM I would be pursuing more accurate statistics for these numbers.
I would like to know how bad Bunz really was.