Sports Reference Blog
Save Percentage+ and Goals Saved Above Average
Posted by Mike on October 9, 2013
Today on Hockey Reference we're rolling out two new stats for goalie pages: Adjusted Save Percentage (SV%+) and Goals Saved Above Average (GSAA). First, you can check Broad Street Hockey for a great explanation of adjusted save percentage and goals saved, but for a simple look, consider the 2012-13 NHL season. League-wide, there were 41,827 shots overall and 3,684 goals scored, for a goals against average of 8.81%. Vezina Trophy winner Sergei Bobrovsky had a goals against average of 6.87% -- 29% better than league average, giving him a SV%+ of 129. Taking that 29% better performance into account combined with the number of shots he faced, we say he saved 21.48 goals more than an average goalie would have, given equal playing time.
These stats are especially helpful for comparing goalies across eras: Patrick Roy led the league in save percentage in the 1991-92 season with a .914 SV%; in the 2012-2013 season that would have placed him as the 26th best goalie between Ben Scrivens and Jonas Hiller. However, we can look at his SV%+ of 130 for that year and see that he was actually 30% better than the league average at stopping goals -- better than Bobrovsky, even.
Note that SV%+ has a minimum requirement of 4 shots faced per team game, so that we don't have goalies who stopped 7 of 7 shots faced in their single period played skewing the results. These stats are now up for goalies as far back as the 1983-84 season (the first year we have shots against data for the NHL), and for the entirety of the WHA (1972-1979), and will be updated throughout the year.
In the future, will you be able to separate Sv% between 5-on-5 and power play?
Good stuff. I think this is more important than even something like Goalie Point Shares. It's a lot simpler and is a good first step into understanding Save% from an angle that people can identify with. GOALS. How many saved goals does that .932 save% represent? Sometimes it's no more than a .923 save% saved.
However, I feel like Save%+ is redundant and GSAA is the more telling stat of the two anyway. I would rather see a GSAA using GAA and then an average of the two Goals Saved stats.
But I hope this catches on with more NHL enthusiasts now that it's on a site like this that more people visit compared to somebody's blog.
Also, I have to add that if you were to make a GSAA for both Save% and GAA, you could then ditch Adjusted GAA as well since it's just GSAA(GAA) without the final step.
If you can't tell, I think Goals Saved is one of the best goalie metrics.
[…] Posted by Neil on October 10, 2013 « Save Percentage+ and Goals Saved Above Average […]
[…] the introduction of SV%+ to goalie stats a little over a week ago, there was some discussion as to whether or not it was the […]