My Problem With Goals Against Average

On February 20th, 2022, Jean-Francois Berube made his first NHL start since April 6th, 2018. 1,416 days since his last start. In that game, his Chicago Blackhawks would lose 1-4 to the St. Louis Blues.

Berube with the Columbus Blue Jackets. Source: chamegu.com

This season, Berube has gone 3-1-0 with a 3.25 GAA and a .924 SV%.

Here’s the thing, those last two stats don’t really correlate each other. You see, the Goals Against Average is really bad, but the Save Percentage is really good. Although he has only played 4 games this season, his .924 Save Percentage puts him in 6th in the entire NHL. And this Goals Against Average would put him in 54th.

Let’s take a look at what is foreseen as a “good” Save Percentage. Google says that it is .915 and above. As of right now that qualifies 21 goaltenders. A “good” GAA is said to be 2.70 and above. This qualifies 26 goaltenders, 8 of which, didn’t even qualify for the “good” Save Percentage. In fact, 3 goalies that are in the “good” SV%, aren’t in the “good” GAA.

The highest goalie in the “good” GAA but not the SV% is Antti Raanta with a 2.44 GAA and a .909 SV%. His SV% actually puts him near the bottom half of the league.

Let’s take a hypothetical scenario. Let’s say Goalie A had 420 shots against him in 10 games (42 shots a game). And he saved 390 of them (39 of them a game). Which means he let up 3 goals a game. Saying he played every single minute of every single game, his GAA would be 3.00. But his SV% would be .929. This is where we encounter a problem. See, his GAA says he did bad in those games, but his SV% says he did good.

Save Percentage does exactly what Goals Against Average does, but it also does what GAA doesn’t do. Goals Against Average is a measurement of how many goals that a goalie gives up in the minutes he plays in a game. Save Percentage takes that and adds shots, so it basically already has that Goals Against Average in it by not adding a save. For Save Percentage, all you have to do is divide the number of saves by the number of shots against.

Anders Nilsson played 7 seasons in the NHL and played for multiple teams. He finished with a career Goals Against Average of 3.06, but his Save Percentage was .902, which actually isn’t too bad. This means that he will save about 90% of the shots you give him. So if 30 shots are against him, he will save 27 of them.

As of right now, the Montreal Canadiens have the worst defense in the league with 198 goals against in 53 games, they also give up one of the most shots in a game. Sam Montembeault has a GAA of 3.53 but an SV% of .902. There’s the issue. Teams who give up more shots, tend to give up more goals. His Save Percentage isn’t bad, but it’s his GAA that makes him look bad.

Overall, GAA isn’t a bad team stat. It helps see how many goals a team gives up a game, but it’s starting to get bad as a goalie stat.

Stats from:hockey-reference.com