The question is, what does unwinnable mean?imo it's more than chances of winning the set or even the game. It's a tool and scenario analysis, and how likely a character is going to get them in a favorable one. Otherwise making ratios past 65:35 is meaningless and might as well be dubbed 0:100. Actually, if we are talking "highest level of play", there are characters that are so badly shutdown in 40:60s that the chances should be labeled as unwinnable, which frankly doesn't sound right, does it?
100:0 sounds more like it's impossible for one character to damage the other. But 65:35 should be "the amount of reward this character will gain in comparison to the other character should be insufficient for winning the match".
MK for example, could ensure winning by getting ahead and simply not approaching in many matchups. Of course, you can't factor this in matchup ratios, because it would skew people's assumptions about being able to win and wouldn't be representative of the metagame at all. Many MKs play aggressive because assuming you get good reads you will **** your opponent harder, at the risk of getting punished, rather than just play to make sure you stay ahead by a safe margin.
This is why you often see different styles/skill levels of MKs still doing well. The absurd amount of options + different ways to play that are still successful mean that you can't even put together everything good about him to make an even more **** character because his abilities stretch out in different directions. But assuming you played every matchup optimally, MK would have practically no matchups harder than 40:60 aside from Snake who would probably be at 45:55.
Anyway, just some logic to throw out there.
Matchups should be represenatitive of the current metagame anyway, but people shouldn't start saying a matchup is winnable just because some top MK lost to some top X.