In such problems, it is usually assumed that your solution have to work (in this case work = better than 50% accuracy) always, even in the worst case, when all unknowns are against you.
I don’t dispute what you say. I just suggest that the confusing term “in the worst case” be replaced by the more accurate phrase “supposing that the environment is an adversarial superintelligence who can perfectly read all of your mind except bits designated ‘random’”.
In such problems, it is usually assumed that your solution have to work (in this case work = better than 50% accuracy) always, even in the worst case, when all unknowns are against you.
https://www.lesswrong.com/posts/AAqTP6Q5aeWnoAYr4/?commentId=WJ5hegYjp98C4hcRt