Unless we are misunderstanding terms, you are incorrect- flat out wrong, so let me see if we are just on different pages:
It is well known that there is no risk management/money management scheme that will make a dice player or a roulette player a long term winner because the player has a "negative expectation" on every bet he makes.
Just like if I let you bet heads on my trick coin that will randomly throw only 40 percent heads, you will not win in the long run no matter how you jiggle your bets (assume i am bankrolled).
Do you agree with this well known fact?
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Perhaps you are not using the term "positive expectancy" as statisticians, professional gamblers, trading quants, etc would use the term.
Here is how those people think of/define the term:
https://en.m.wikipedia.org/wiki/Expected_value