While Goalies Are Nearly Random
In the NHL, team defense doesn’t correlate to goaltending as much as you would think. Defense obviously does make some difference, but it is my experience that most people are surprised or skeptical about the idea of defense and goalies not matching up exactly.
For whatever reason, the teams with the best defense are not automatically the teams with the best goaltending.
Here is a quick example of what I mean:
For the last 3 seasons (209 games) the team’s with the lowest Expected Goals Against per game are Boston, Minnesota, Colorado, Dallas and Tampa.
Here is how those teams rank by save percentage over the same period: 5, 14, 2 , 3 ,7.
One reason why defense may not be the difference maker we would suspect is that pretty much anyone capable of being an NHL goalie is going to be amazing at stopping low danger shots. There isn’t going to be any difference between Michael Hutchinson and Andre Vasilevskiy at stopping easy shots because there is a limit to how good you can be at the skill where you will stop 100% of the shots you don’t make a mistake on. (All stats naturalstattrick.com).
Therefore, any goalie with a low save percentage against easy shots is just in a luck based slump. Team defense isn’t going to help any goalie having an off year on shots that are labeled “easy” by the official scorer. (For an example of what I mean, the “worst” goalie in the NHL to play minimum 20 games this year at saving Low Danger shots had a .969 save percentage, while the best who played at least 20 games had a .979%). (These stats specifically from moneypuck.com).
Where team defense does matter, is in limiting high-danger shots. If your team’s goalie isn’t ice-cold, he should save nearly all the easy shots, and if your team limits the dangerous ones, he will do better.
Except that the range of how many dangerous shots teams allow per game is tiny. The best defensive team in the NHL only allows four less dangerous shots against per minutes of 5v5 ice time (which is actually more than one game) than the worst defensive team.
That doesn’t sound like a lot, but at the pro level tiny margins can matter (especially in a cap league).
So if a team wanted the best goalie possible, they should look at high-danger save percentage, and try to acquire the goalies who are best at saving those shots.