He was excellent in international play.
In an international career spanning 207 games from 1968 to 1984, Tretiak put up a GAA of 2.21, capturing 3 Olympic golds (and one silver), 10 IIHF Championships, 13 European Cups, one Canada Cup, and 12 Izvestija Cups. He most famously held together a Soviet team that was haemorrhaging shots-against in the 1972 Summit Series with Canada, and though today's NHL would find his save percentage for the series (88.4%) none too impressive, it was actually very close to NHL league average in a period when NHL goalies weren't facing Team Canada every night. Canadians will also recall his performance in the 1976 Super Series, where he held the tie for a Soviet team that was outshot nearly 3-to-1 by the Montreal Canadiens on New Year's Eve. He was stellar for the bulk of the Series actually, posting a 92.9% save percentage. In the LOES post on "lifetime trophies", Tom Awad commented that he had Tretiak's performance in the '72 & '74 Summit Series and the '76 & '81 Canada Cups at .7 GVT per game, and used Hasek's NHL career as a comparative (.52 GVT per game; .66 GVT in his peak years from 1994 to 2002).
He was very successful in the Soviet League.
CSKA and Tretiak won 13 Soviet League titles during his career, and he won the league's MVP award five times, in 1974, 1975, 1976, 1981, and 1983. If I'm to trust the data on this site (I'll get to that in a bit), Tretiak posted a 2.40 GAA in nearly 500 games, a solid number in any league at that period in time.
Yeah, there's that, too. Canadians respected him because he proved capable even in the hail of bullets that were some of those series in the early to mid-1970s; Americans respected him because he and the rest of the Soviet teams were better than the Americans. You'd probably find similar sentiment in Europe, though the Czechs/Slovaks had a long rivalry with the Soviets and were able to beat them on occasion.
He played for great teams.
I don't want to present the Soviets or CSKA as a monolithic superstar team, because the fact of the matter is that they had highs and lows like anyone else. But it is hard to say the Soviet Union was anything but spectacular in international competition during Tretiak's career (in 422 games, they went 348-45-29, for an 82.5% winning percentage), and the same for CSKA in the Soviet League (in 595 games, they went 481-69-45, for an 80.8% winning percentage). Tretiak might have won 5 MVP awards, but CSKA players carried 13 of the 15 MVPs won over Tretiak's career, including Boris Mikhailov (2), Valeri Kharlamov (2), Sergei Makarov, Vyacheslav Fetisov, Anatoli Firsov, and Nikolai Drozdetsky. From 1969 to 1984, CSKA led the Soviet League in goals-for every single year except twice (they were 2nd by 9 goals in 1973-74 and 1 goal in 1975-76); they averaged 243 goals-for in those years, while the second-place teams averaged 203. It seems that a major benefit of being on CSKA is that you didn't have to play CSKA!
Finally, when pitted against NHL teams over the same span CSKA held it's own, going 10-4-1.
The numbers don't add up.
The Tretiak year-by-year statistics I referenced earlier are very problematic. Like I said, they give us the portrayal of a goaltender that allowed 2.40 goals per game, on a team in which he wasn't just the primary goaltender but, in his hey-day, the only goaltender. So, what explains the gulf between CSKA's cumulative goals allowed and Tretiak's? For instance, in 1974-75, am I supposed to believe that a CSKA team that played to the tune of 2.97 goals-allowed per-game turned around and gave up 18 goals in the one game Tretiak didn't play? Or, in 1976-77, a 2.80 GAA team giving up 15 goals in one game? Or maybe they allowed 33 empty-net goals in the 4 combined losses in those years. There were similar discrepancies in 1971-72 and 1972-73, at which point I determined that we'd be better served at looking at team goals-against rather than settling for the idea that CSKA just put a board up if Tretiak wasn't able to play. By the 1980s, the data actually started to make sense, so from 1980-81 onward I gave them the benefit of the doubt. Lo-and-behold, we see Tretiak's GAA jump to 2.75, with a 3.07 GAA in the 1970s.
His Russian contemporaries were possibly just as good.
Ever hear of Viktor Konovalenko? The premier Soviet goaltender of the 1960s, Konovalenko essentially was the guy who passed the torch to Tretiak after 1971. His GAA in international competition from 1969 through 1971? 2.22. There was even a goalie who played alongside Tretiak in the 1970s, Aleksandr Sidelnikov, who was quite talented as well. He played for one of the few teams to break the death-grip CSKA held on the Soviet League in the 1970s, Krylya Sovetov. During the 1973-74 season, he was the primary goaltender on a team that allowed 87 goals in 32 games, with the next closest team (Dynamo Moscow) allowing 114. Playing most of his 38 international games against Finland and Poland (Finland was 5th/6th best in the world in the 1970s; Poland 7th/8th), he put up a 2.26 GAA. A third contemporary, Vladimir Shepovalov, posted a 1.78 GAA over 14 international games, but most of his competition was weaker. What we see is that, in general, this was a transcendent Soviet team that performed quite well regardless of who was between the pipes. To highlight the losses in 1972 and 1980 ignores the larger body of work.
Within the Soviet League itself are more interesting data. For as dominant as CSKA was over Tretiak's career, they did not always have the fewest goals allowed:
Year --- Goals-Against Rank (Soviet League) --- # Goals Allowed --- # GA League Leader (or 2nd place)
1969-70 --- 2nd --- 121 --- 119
1970-71 --- 1st --- 95 --- 116
1971-72 --- 1st --- 94 --- 95
1972-73 --- 2nd --- 102 --- 82
1973-74 --- 3rd --- 121 --- 87
1974-75 --- 2nd --- 122 --- 120
1975-76 --- 2nd --- 116 --- 105
1976-77 --- 4th --- 113 --- 103
1977-78 --- 2nd --- 109 --- 104
1978-79 --- 2nd --- 131 --- 124
1979-80 --- 1st --- 118 --- 127
1980-81 --- 1st --- 113 --- 134
1981-82 --- 1st --- 91 --- 135
1982-83 --- 1st --- 73 --- 93
1983-84 --- 1st --- 80 --- 109
In his final season, Tretiak only played half of CSKA's games. His backup, Aleksandr Tyzhnych, put up identical numbers.
As you can see, CSKA truly became dominant again with the maturation of Sergei Makarov, Igor Larionov, Vladimir Krutov, Vyacheslav Fetisov, Nikolai Drozdetsky, and Alexei Kasatonov, among others. In the 1970s, CSKA was constantly challenged by Dynamo Moscow for fewest goals allowed, as well as Khimik Voskresensk (with occasional CCCP and, before 1974, Dynamo goaltender Aleksandr Pashkov) and Sidelnikov's Krylya Sovetov. Yet the goaltending for those teams was rarely given the spotlight that Tretiak was, and the international accomplishments are a large part of that. But could it be possible that Tretiak was viewed as a "clutch" goalie and used internationally regardless of his contemporaries? Or that politics/propaganda were involved (he was the primary goaltender on a team that represented the Soviet Army, and other teams were affiliated with political and military institutions)?
If nothing else, I'd argue that Tretiak and the prominence of the CSKA teams has cast a shadow over a number of other great players in the Soviet League, particularly goaltenders. Those of us that know a bit about Soviet hockey history can name guys like Aleksandr Maltsev, Helmut Balderis, Aleksandr Yakushev, and maybe a couple of other skaters, but goalies like Aleksandr Sidelnikov and Aleksandr Pashkov need to enter the conversation as well.
Vladislav Tretiak's career is incredible in that he did so much in such a small amount of time. In the process, he challenged some of the giants of the game, and was often able to come away a winner (or at least the most respected player on the ice). There is no doubt in my mind that those pinnacles of achievement are noteworthy and great enough to give him a place in the Hall of Fame, but I have some doubts when the conversation turns to the "best goaltender in hockey history."
Many thanks to CCCP Hockey International and Arthur Chidlovski for a good chunk of the data; the remainder was pulled from hockeydb.com and the links I've provided.