For example, yesterday I raised to 7$ from the cuttoff with AsKs5h4d. The button and small blind called. Then, the big blind (a very loose player) min-raised to 16$. All but the small blind called. The flop came Kh Kc 10c. The big blind checked to me and I bet 30$ into a nearly 40$ pot. Everyone folded but the big blind, who called. The turn came the 9clubs, putting both a straight and a flush on the board. The big blind lead out into me, for the size of the pot (100$). I had about 150$ behind, and had to figure out what to do.
Tricky tricky tricky. On the one hand, my trip kings are now beat by both straight and flushes. In theory, that means I should fold (I don't have the right pot odds to call in hopes of making a full house on the river). If I am going to call, I have to shove my stack into the pot; there's no point in calling off 100$ and leaving 50$ behind. The question is, what does my opponent have?
In hold'em this might be an easy fold. The problem is that Omaha is not Hold'Em. When I bet the flop, I'm representing at minimum three kings. However, it's pretty likely I could have a full house at that point, and my opponent should know that. The range of hands that I would raise and then call a reraise with preflop includes lots of kings and tens. Furthermore, I WOULD bet a full house in that spot; I want to get value from a lesser king, first of all, and I know the big blind doesn't respect my bets very much at this point and will call just about any flop bet (at least he has been so far). There's no reason to check the full house there, and I wouldn't do it.
His lead on the turn represents a made hand. The question is, would he chase a flush or a straight draw with a pair on the board? In general, doing so in Omaha, is, as they say, bad cess. Calling out of position to hit a non-nut hand seems like a pretty poor play, and though my opponent here is loose and aggressive, that doesn't mean he's stupid. He knows my flop bet represents at least three kings. He can't know if I have a full house or not, but he at least knows it's possible. The normal line for someone who'd made a straight or flush on that turn would be to check and call, hoping that I wouldn't bet unless I actually had the full house. There's no point in leading out right there; you can really only get called by better hands.
I write all this, although thinking back I can now see reasons why a flush might bet there; especially if he puts me on a hand like the one I have. But, as I noted, the big blind is playing very loose and making a number of large bets. So far I haven't seen him show many hands (he's been mostly running over the table) but I know he's betting way too often to have real hands every time. So, after taking time to think, I push all-in. He insta-calls and I figure: I'm dead. (Even if I'm wrong, I decide that I have outs to a full house). And he shows....nothing (Q 10 6 7). He's drawing mostly dead, and when the river bricks off, I scoop the pot.
Happy days. Tough decision though, and one of the reasons I both love and hate Omaha.