Set Mining Math

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Assuming 100BB stacks for both the hero and the villain, at what size 3-bet does it become -EV to set mine... we will assume you standard preflop raise to 4x BB preflop with no limpers in front of you and no callers behind and then the villain 3-bets you... lets also assume this is a decent player (well go with 20/15)

Does position in this situation matter at all? Like say he 3 bets you from the button as opposed to from the blinds... would this have any bearing? I figure he will CBet you from the blinds nearly every time so it will be easier to extract money from him when you do hit your set, but if you are first to act, it is harder to stack him off (at least in my experience)