Poker trivia puzzle

[slapdash]

You're all-in, heads-up, Texas holdem. Assuming your opponent doesn't show you his cards, is it possible to know that you've lost (split pot doesn't count): (a) When the river card is dealt? (b) Before the river card is dealt? And ©, (d): same questions but it's Omaha (high).

[daftpegasus]

Re: Poker trivia puzzle If after the river is dealt your best hand is 9 high then you know you've lost (only a split pot would save you). Pre river there's always a chance. I don't know enough about omaha to discuss with any certainty but there must be a similar situation when post river you have the worst possible hand there is (I'm guessing that it's something around Jack high).