I have been playing poker on pokerstar.net, and for several occasions, there have been a straight flush and a full house on the same flop/game, I just think that this is an impossibility. Just what clarification if this is actually a possibility.
On the flop in hold-em, it is not possible for one player to have a straight flush (or even just a straight or just a flush) and another to have a full house. A full house requires at least two cards on the board to have the same rank. A straight (or flush, or straight flush) on the flop requires that no cards on the flop be of the same rank. These are mutually exclusive, so it's not possible.
On a full five-card board, though, it's entirely possible. Say two players had these hole cards:
- A♥ A⋄
- J♠ T♠
and the board runs out like so: A♠ K♠ Q♠ Q♥ 5♥
Then the players' final hands are:
- A♥ A⋄ A♠ Q♠ Q♥ -- a Full House, Aces full of Queens.
- A♠ K♠ Q♠ J♠ T♠ -- a Royal Flush.
So, no it's not possible on the flop, but it's entirely possible by the turn and river.