For all of the cases in shas where we talk about migo, it isn't possible that a migo would be a viable proof if the person making the claim knows about the concept of migo because then he could easily outsmart the system by intentionally claiming lower claims. How do we reconcile this fact with the gemara's use of migo when the cases seem not to distinguish between those who know about migo and those who don't? For example, are we to assume that Rava bar Shirshum didn't know about migo?
Reuven Pinsky, Waltham, USA
A "Migo" never works where the "better" claim would not be accepted and win the case for the person. Therefore, there is no reason to "outsmart" the system. The better claim would be believed and leave him in a better position.
Regarding Rava Bar Sharshom, he certainly knew about the concept of "Migo," for he himself declared that he had a Migo.
D. Zupnik