Of course, 50% is the ideal measure, but that is completely unrealistic for any champion to be at exactly 50% for an sustained period of time. So what is the margin of error that would be considered acceptable?
Honestly 50% isn't nessecarily right for everyone.
The ideal winrate for a champ depends on their playrate, player average experience, the current meta, and the skillcap for said champion.
100%
I would think 48-52% is ideal. That leaves +/- 2% for outliers such as team comp, experience, matchup, etc, etc, etc.
Win-rate alone is a terrible measurement.
They seem to be comfortable with a +/- 5% as long as there are other factors in play. Lee Sin for example has a 45.7% win rate at the moment, but this doesn't seem to concern them as he is a high skill floor, high skill ceiling champ, and is a fairly popular pick.
Broken champs used to have around 60 % winrate - prenerf devourer red smite WW, reworked Skarner, "nerfed" Ahri.
some champs are easier to play, but fall off at higher Elo.
Others are harder, but are favorites amongst pros.
Why would general win rates be used for balance exactly?
Winrate alone is not a good measurement. Obviously outliers are an issue, but there are many other factors that go into deciding what is too high or too low.
