[2461Badugi]

The key is that villain can easily be betting his board here. Even presuming he started with a legitimate hand, he still has a pair here a lot; if he has exactly one pair you make a load of money on your raise, because he's way behind but he still has to call and try to suck out. Whereas if he does have a made 87, you're losing very little (and may actually be ahead depending on the dead card situation).

Against some very aggro players (like me sometimes) it can be better to call down, because they'll put bets in dead bluffing if you let them keep the betting lead.