Suppose you are right 90% of the time in some activity, where you gain $1 for being right, lose $1 for being wrong
Suppose a new strategy is right 80% of the time, wrong 20%, but with ± $2.
Your expected value change is +40c.
Moral: There is such a thing as being too right 
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You've almost phrased the question in terms of the parts of the sharpe ratio already, even.
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Phrase it so there's an cost for each attempt and you can look at it as a return and fit it into the formula.
End of conversation
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