Quick quiz

You're playing heads up. Blinds are 50/100, the small blind calls in the dark, and you check your option with A7 (I know you should raise, but we're setting up a quiz here). The flop comes 345 rainbow. You act first after the flop.

How much do you need to bet so that it would be a mistake for the SB to call in the dark? Probably best if you try to answer based on your gut feelings, obviously you can find out the odds with PokerStove or similar.

(Ok, it would always be a “mistake” in some sense for the big blind to play this way -- what we're asking here is what are the A7 odds against a random hand).

Can't think where this might have come from ...