As I have written about many times on this blog, NHL save percentages are quite dependent on the strength of the team in front of the goaltender. If this is the case in a league with a high degree of parity, we should logically expect the team effect to be even more significant when teams are not on a level playing field.
Looking for a more unbalanced competitive scenario than the NHL provides, I chose to investigate international hockey results. There are goaltending statistics available for most of the major international tournaments since 2000 on the IIHF website. I looked at senior men's competitions (world championships, Olympics and World Cups), the U20 junior men's world championship, and women's competitions (world championships and Olympics).
After calculating the total shots against per game and save percentages for each country in each category, I ran the correlation coefficients for shots against vs. save percentage:
This shows a very high correlation between shots against and save percentage, a typical result for an unbalanced competitive environment. All three tournaments suffer from a lack of competitive balance. There are a few teams that are contenders to win, a few teams that will make a game of it against the best teams, and then there is the rest of the world which gets completely dominated by the best teams. The best teams give up few chances to score against, while the worst teams give up lots of high quality scoring chances.
The drop-off in talent is not equal, however. There are a lot more teams that have the capability of winning a men's world championship than a women's world championship. If we look at the top 8 teams only, and again compare the correlation coefficients between save percentage and shots against, we see a distinctly different result on the men's side:
For the best men's teams, there is no relationship between save percentage and shots against. This is similar to the NHL, where there are a number of different teams on a fairly level playing field. Among the top womens and junior teams, the teams that do the best job of preventing shots are also much more likely to allow easier shots against. The better teams also probably have better goaltending, but the effect is much too strong for that to account for the entire difference. It is much more likely that a country like Switzerland would be able to be competitive with Canada in goaltending than that they would have competitive in overall team strength, since they would only need to develop one elite athlete as a goaltender compared to developing an entire team of top players.
Now let's move on to look at what kind of expected save percentage results we can expect for various countries in international play. On the men's side, the top teams are very close to each other in save percentage. There isn't a single team that has a huge advantage in terms of goaltending, and somewhat surprisingly Canada did not lead in any of save percentage, GAA, or fewest shots against per game:
1. Finland, .923, 1.85, 24.0
2. Canada, .921, 2.09, 26.3
3. USA, .919, 2.23, 27.4
4. Czech Rep., .914, 2.10, 24.5
4. Russia, .914, 2.20, 25.7
6. Switzerland, .910, 2.69, 29.9
7. Sweden, .909, 2.19, 23.9
8. Slovakia, 906, 2.28, 24.3
This supports Finland's emergence as a goalie hotbed. On the other hand, Sweden is a country that has sometimes struggled with goaltending despite a strong defence (although they are in better shape now with Lundqvist). Slovakia's strong team defence results suggest that they employed a shot prevention strategy, which was a smart move given the unremarkable goaltenders they have had.
About 40% of the Canadian sample is made up of Brodeur and Luongo, the two most-used Canadian goalies in recent international tournaments. The two of them also had very similar stats in the sample (Luongo: 2.03, .926, Brodeur: 2.01, .925). Brodeur faced slightly fewer shots per game than Luongo (26.8 to 27.5), but Brodeur's shots per game were still slightly above average for Canadian goalies, which doesn't support the view that he has a huge impact on shots against (although the international ice could possibly have something to do with that as well).
In the junior tournaments, we start to see more of a separation between the best teams and the rest of the pack:
1. Canada, .936, 1.63, 25.5
2. Russia, .920, 2.08, 26.2
3. Czech Rep., .910, 2.35, 26.1
3. Finland, .910, 2.51, 27.8
5. Sweden, .903, 2.43, 25.1
5. USA, .903, 2.59, 26.7
7. Slovakia, .895, 3.06, 29.3
8. Switzerland, .886, 3.30, 29.0
Canada almost always has the best defensive team in the world juniors, so playing goalie for Canada is a big advantage. Dustin Tokarski was pretty mediocre this year in net for Canada, but still ended up with a .906 save percentage.
In the women's tournament, there is a huge gap between the top teams and the rest:
1. Canada, .947, 0.87, 16.3
2. USA, .920, 1.26, 15.7
3. Switzerland, .904, 3.50, 36.2
4. Finland, .894, 2.73, 25.8
5. Sweden, .882, 3.27, 27.7
5. Russia, .882, 3.45, 29.6
7. Germany, .881, 4.14, 34.9
7. China, .881, 4.54, 38.2
I don't know much about women's hockey, but there are a few European goalies who had some pretty impressive results considering the strength of their teams: Sweden's Kim Martin (.897 on 562 SA), Finland's Noora Raty (.911 on 293 SA), and especially Switzerland's Florence Schelling (.920 on 488 SA). On the other hand if you play for Canada or the United States, you pretty much just have to stand there and watch your team score.
It is probably fair to say that Canadian junior and women goalies are better than average, but most of the gap between Canada and everyone else in those tournaments is likely a result of shot quality against. If Canada had received merely average goaltending, then to achieve the observed save percentages the shot quality against would have needed to be 40% easier than average for the Canadian junior teams and 52% easier than average for the Canadian women's teams. I doubt it was that high, but the true figure still certainly falls well outside of the typical 10% boundaries seen in NHL competition.
Overall, the data support the theory that shots against and save percentage are positively correlated in hockey when the competition is unbalanced. In that type of environment it is much easier to play goalie for the best teams, and that should be taken into account when evaluating, for example, Canadian goalies at the world junior hockey championships. When the competition is tight, then the shots/save percentage relationship largely disappears.
It is likely that this relationship holds throughout the history of the NHL as well. In the few seasons we have of save percentage data from post-expansion era in the 1970s, for example, shots against and save percentage were positively correlated. I would expect similar results for the early years of the NHL, and during much of the Original Six era. That makes it even more important to take team strength into consideration when evaluating goalies from these periods.