For the love of God will somebody answer my coinflip question?

[Proofrock]

100BB max buy-in game, you have ~ 800BB and at least one other player at the table has you covered. What is the minimum edge you need to call a preflop all-in from a player who has you covered (for simplicity imagine you're in BB and the other player open pushes from SB)?

If the answer is any hand for which you're >50% to win, explain why the 100BB max buy-in doesn't factor into the decision. If the answer depends on information not given, please explain what factors are important to consider and how they would effect your decision.

If this is the wrong forum, let me know where it belongs.

-J.A.