InGoal Magazine Staff | Dec 20, 2018 | 0
It’s Time to Scrap Goals Against Average
It’s time to do away with goals against average, at least when it comes to evaluating goaltenders.
Goals against average used to be the go-to stat that everyone pointed to when trying to judge a goaltender’s performance.
It’s a hard number. It’s easy to calculate. It tells you everything you need to know about how a goalie is playing, right?
Goals against average was one of the first hockey statistics to be calculated. It even predates save percentage, which wasn’t officially tracked by the NHL until the 1983-1984 season.
For decades it has been the stat that every beer leaguer points to, showing how great they played. Alongside wins, it has been the reason that many goalies have walked away with the Vezina Trophy.
Heck, goals against average even has a trophy of its own – the William M. Jennings Trophy.
Goals against average is important, there is no discrediting that. The basis of the game relies on keeping the puck out of the net, and scoring on the other one.
What’s wrong is how it is applied to individual goaltenders.
Goals against average is altered by a variety of factors, and it cannot realistically tell us anything about an individual goaltender. It is simply a team stat. Nothing more, nothing less.
Goaltenders have no control over how many shots they face. They have little control over how many penalties their teams take. They have little control over where the shots they face are coming from, or how plays develop.
All of these points, at varying degrees, have an impact on a goaltender’s goals against average. Collectively, the team influences those things – so why do we still look at goals against average as a stat that a goaltender can control?
Goals against average does not reflect performance
Roberto Luongo’s 2005-2006 season was one of the best performances of the last decade, but you wouldn’t know it by looking at his goals against average. Not coincidentally, he finished 7th in Vezina Trophy voting that year.
His save percentage was slightly above average at .914, and his goals against average was 2.97. That’s dismal by modern expectations.
Luongo gave up the most goals in the entire league that season – 213. A league-average goalie in his place would have allowed 32.64 more. A league average goalie would have had a 3.42 goals against average.
Based on the number of shots he faced (an obscene 2,488, or 34.7 per game), and the fact that he played 75 games that season, it’s actually miraculous that Luongo was able to put up the numbers that he did.
A common argument that is used for goals against average is that great goaltenders will always have a great goals against average, so it has to tell us something.
That is very, very false.
Yes, most great goaltenders will have a great goals against average, but a lot of sub par goaltenders will have a great goals against average as well. A lot of good goaltenders will have a terrible goals against average.
A great example of this can be shown by comparing Michal Neuvirth and Ben Scrivens from the 2014-2015 season.
Both goalies play for teams that have unstructured defences, but Neuvirth saved the Sabres 4.46 goals against based on his save percentage compared to the league average. Scrivens has allowed 18 more goals than a league average goalie.
Neuvirth’s goals against average sat at 2.99 with the Sabres, and Scrivens is 2.91. Neither of those numbers are great, but the goalie that has actually performed above average has a higher goals against average than the goalie that is well below the league average.
The cases aren’t always that dramatic, but it happens a lot, and many goalies are unfairly chastised based on their poor goals against average when it really isn’t their fault.
Is save percentage better?
Save percentage is a slightly better statistic, but is still hardly perfect. It at least takes into account how many shots a goaltender faces, but that is still not something that a goaltender can control. Also, as pointed out in a previous article, a high shot total doesn’t really have a negative effect on a goalie’s save percentage anyway.
Goals against average is basically save percentage, but without the filter of knowing what kind of workload a goaltender has been getting.
As far as goaltender evaluating is concerned, goals against average is basically a crummier, low-brow version of save percentage. All it does is muddle people’s perceptions of goaltender performance.
Simply looking at his goals against average tells nothing except for the end result. It gives no information of how the goaltender got to that number.
The factors omitted by goals against average contain the information that we should be judging goaltenders with, instead of glorifying the end result.
Reliable, informative goaltending statistics
So what happens now? If goals against average can’t be used to evaluate goalies, and regular save percentage isn’t perfect, what can we use?
It has long been said that goaltending does not exist in a vacuum. It’s the hardest position to play, and it’s also one of the hardest positions to statistically quantify.
Every statistic will rely somewhat on team play. As mentioned before, goalies have little control over how plays develop, the shots that they face, and the shooting percentages of the players taking the shots.
What we can evaluate is how goaltenders perform under certain conditions.
Shots from different areas on the ice yield different save percentages from goalies. For example, a shot from the boards by the blue line has less of a chance of going in than a shot from directly in the slot.
War-on-Ice has a wonderful tool that breaks down where shots are coming from on the ice, and adjusts the save percentage based on how we know goalies are expected to perform on shots from that area.
It’s called “Adjusted Save Percentage” and a lot of work has gone into making sure that the shots are plotted correctly (NHL.com can be a bit sketchy at times), and they even break it down so you can tell how a goaltender performs on low-danger, medium-danger, or high-danger shots.
Goals Saved Above Average is a statistic that has been discussed on InGoal before, and Stephen Burtch of Sportsnet.ca has taken it even further, introducing War-on-Ice’s adjusted save percentage to the formula rather than regular save percentage like Hockey-Reference does.
Goals Saved Above Average is nice because it’s very blunt, and tells you exactly how much better, or worse a goalie has been when compared to the league average.
In the 2013-2014 season, the average save percentage dropped 4.4% while on the penalty kill. Taking special teams out of the equation and looking at even-strength save percentage can be important, because some goalies are unfairly punished by playing for an undisciplined team.
Left Wing Lock breaks down all three different types of save percentages nicely. Although looking at a goalie’s penalty-kill and power play save percentage can be interesting, keep in mind that the sample sizes are very small, and can wildly fluctuate from year to year with a goaltender.
To recap, Goals Saved Above Average, Adjusted Save Percentage, and Even Strength Save Percentage may seem new and confusing, but the reality is that they do a much better job of highlighting a goaltender’s performance than traditional statistics do.
It still isn’t perfect, and it may never be. That’s why there will always be a place for the eye test when it comes to goalies. Hopefully with the NHL starting to track players in the next few seasons, more accurate stats start to appear – but this is all we have for now.
There is no holy grail of goaltending statistics. All of these stats tell a part of the story of how a goaltender is performing, and, when forming an opinion, it’s important to look at all of them.
All of them except for goals against average. It’s a team stat, and it’s time to scrap it from the goalie conversation.