One of the great benefits of the Hockey Summary Project has been filling in the gaps in the save percentage record going all the way back to 1952-53. That greatly expands the potential analytical work that can be done on hockey goalies throughout history before the NHL began officially tracking shots and saves in 1983-84.
I got the idea to run the numbers on Montreal backup goalies in the 1970s after following along with the terrific work being done by Black Dog Hates Skunks on the 1972 Summit Series. The scoring chance numbers being compiled there make a pretty good case that Canada was the superior team, but that perhaps the biggest reason the series ended up being close was lackluster goaltending by Ken Dryden.
It shouldn't be too surprising that it would be easier than normal to play goalie on a team that had Larry Robinson, Serge Savard and Guy Lapointe on defence in an unbalanced league further ravaged by player losses to the WHA. The question is how much? Here are the numbers:
Montreal: .901 on 2178 SA
Elsewhere: .889 on 9412 SA
Montreal: .904 on 1432 SA
Elsewhere: .881 on 11317 SA
Montreal: .912 on 5391 SA
Elsewhere: .890 on 16221 SA
Montreal: .888 on 866 SA
Elsewhere: .880 on 8015 SA
Montreal: .906 on 1424 SA
Elsewhere: .886 on 5563 SA
Montreal: .894 on 5860 SA
Elsewhere: .861 on 1829 SA
Average save percentage for Dryden backups in Montreal: .902
Average save percentage for Dryden backups elsewhere: .885
I don't think anybody should be surprised by the confirmation that being the Habs' netminder in the 1970s was a pretty sweet gig.
That second number is actually even lower if you weight the other goalies' save percentages based on how much they played in Montreal, although Larocque's numbers have a big effect there since he makes up such a large part of the sample and has a comparatively low amount of playing time outside Montreal.
It's possible that the difference between some of these goalies is somewhat exaggerated as they would have been more likely to face expansion teams as a backup in Montreal and more likely to face the league's best teams (including the Canadiens themselves) as a starter in Pittsburgh or Kansas City or wherever else they played. It's not always an apples-to-apples comparison either because some of these guys were on their way up or their way down when they went through Montreal. Still it's a six goalie sample that supports what we already know: that the Canadiens had such a strong defence. On top of that, the Habs also did not take many penalties, which would be a further benefit for the team's goalies.
If we adjust Dryden's numbers based on the above difference, his career .921 becomes .907. That remains a very good number, given that the league average over that period was .893, but that certainly puts Dryden in the conversation with Tony Esposito (.912 over the same stretch) and Bernie Parent (.914 in the same seasons on a much more heavily penalized team) for the title of the best goalie of the 1970s.