More than you ever wanted to know about backup goalies.
We find ourselves in a weird part of the season. The trade deadline has come and gone, and the big acquisitions have gone from novel and exciting to just part of the scenery, like a fancy new toy a few weeks after Christmas. With 11 games to go, it feels like there should be a sense of urgency, except there’s not, really. We basically know where the Rangers will finish in the standings and that they’ll play the Devils in the first round. Instead of a mad dash to the finish, the Rangers can kick it into cruise control until the games matter again. Thanks, Divisional Playoff Format.
While we’re mired in this slow period, why not spice things up with a semi-deep dive into nobody’s favorite topic: backup goalies! Please, try to contain your excitement.
A little while back in the BSB Slack, dearest Mike Murphy tossed out some ideas for articles, including “was Jaroslav Halák a mistake?” Even though this was before his recent shutout, I was somewhat surprised. I’ve felt Jaro has been a perfectly cromulent backup tendie. But perhaps I was missing something. So I dug into the numbers a bit, and–spoiler warning–nah, Halák is totally fine.
Basic Stats and Context
Looking at his boxscore stats, my gut reaction is: “Okay! That looks adequate!” If anything, the .905 SV% maybe feels a little low, even if scoring is up this year. That GAA looks really solid though! Still, I wondered, how good does a goalie need to be to be a good backup goalie?
For the sake of comparison, I looked at each team’s top two goalies in terms of TOI in all situations for a total of 64 goalies. In most cases, this is a starter and a backup or a 1A-1B situation. Obviously some teams have had to use more than two goalies, but I don’t think it’s all that helpful to compare Halák to, like, the fourth goalie on the Sens’ depth chart (sorry Sens). Also, goalie talent isn’t evenly distributed; a few teams, like the Canes, have three solid netminders, while others, like the Sharks have none. Still, I wanted to compare Halák against the goalies who have actually gotten the most ice-time for each team.
To start, I took the average SV% and GAA of those 64 goalies:
Halák looks pretty good here! His SV% is about average with a significantly lower GAA. However, no one is expecting a backup to play like Ilya Sorokin. So let’s compare Halák to his more direct peers. Here are those averages again, but this time separating out the most-played goalies on each team (G1) and the second-most-played goalies on each team (G2).
As expected, the G2s are worse as a group; they would probably get more ice time otherwise! Halák looks quite a bit better than the average G2, and his SV% is similar to the average G1. Not bad.
Goals Saved Above Expected
Although goalie remains the most Mysterious position, we do have more informative stats than the basics. As we know, not all saves are created equal, and team defense can have a heck of a lot to do with GAA. So let’s shift our focus to GSAx, or Goals Saved Above Expected.
Here’s a quick review on Goals Saved Above Expected:.
Goals Saved Above Expected is simply the Expected Goals (xG) a goalie has faced minus the number of goals that goalie has allowed. A positive difference means a goalie has saved more than they “should” have saved, a negative difference means they have given up more goals than the “should” have. Though public models of xG differ slightly, they consider factors like shot location and type to assign a likelihood of a given shot becoming a goal. xG isn’t perfect but that doesn’t mean it’s not useful. If I’m cutting a log and I don’t have a chainsaw, I’d rather use a hatchet than a kitchen knife. Ya dig?
Per Natural Stat Trick, Halák has faced 57.68 xG, meaning that based on measurable shot quality, we’d expect him to have conceded about 57-58 goals. In reality, he has only given up 54. So to calculate his Goals Saved Above Expected, we subtract: 57.68-54= 3.68. Great! Once more, let’s compare how this stacks up to other samples of goalies:
Here we can see more separation than when we looked at SV%. Halák is miles ahead of the average G2 and right on par with the average G1. The latter might sound surprising, but some teams continue to ride a poor G1 due to past performance, contract, or because they’re not really trying to win (hello, Elvis Merzlikins). Halák obviously has an easier workload than G1s, and I wouldn’t necessarily expect him to post such numbers as a starter. But again, no one is asking him to do that.
Conclusion:
In accordance with Betteridge’s Law, no, Halák was not a mistake. Despite a couple rough patches, he has been solid overall, especially when compared to the average second-string goalie. If there’s one thing this exercise taught me, it’s that good goaltending is even scarcer than I realized. There are only 10 teams whose top two goalies both have a positive GSAx, and thanks to Halák, the Rangers are among them. It’s rare that a backup goalie will make or break your season, but I’m all for raising the team’s floor, and Halák has done that this year. At 37 years fun, Halák’s time as a positive contributor may be drawing to a close, as goalies tend to age like milk in the sun. But for now, Halák is what he is, and he is just fine.
Stats are courtesy of Natural Stat Trick and current as of 3/20/23.