What you're actually describing is usually called the "bare ace bluff"; that is, betting the pot when there's, say, 3 clubs on board and you have the A[c], knowing that no-one can call unless they have a set (drawing to the boat) or, perhaps, 2nd nut flush. You can bet I wouldn't be playing 2nd nut flush there myself, but some loose types will! My natty little article on PLO post-flop betting plays on the main page of the BTP site goes into a little detail on this, which you might want to look at; otherwise, here's my thoughts on it...

On the whole, I'm not a big fan of the play, it gets called just too often for my liking. The problem is that if you DO get called it's hard to figure out if you're up against the 2nd nut flush (in which case you can resign gracefully) OR an opponent on a set, in which case the correct play is to maximum bet the turn and then bet about 1/4 pot on the river to get him to lay down if the board doesn't pair. This is, essentially, the problem; if you're called you just don't know where you are. IF the board then pairs, he might have K-high and drop to a bet, but he might've just made a boat and you're pushing your money in with no hope.

However, in some cases it's a very useful move. I have made good money in the past doing it against players I KNOW are good, and so when they make a call I can put them more solidly on a set. It's even more useful if you hold position, and then can see how they react if the board pairs. Usually, if I make the bare ace bluff against a good player, I'll bet hard until the river, and then, as described above, make that small bet to lose any missed sets. You need to know your opponent though, and into a good-sized field it's less than ideal, especially on a draw heavy board where, at PLO25, some goon with broadway straight, any of the top 3 or 4 flushes, or perhaps even a set with a weedy flush on the side, will come along for the ride. It is a very opponent-specific play and usually you're looking at the following requirements:

1) No calling stations left to act (obviously)
2) No pairs on board (obviously)
3) Ideally, 3 opponents max, 2 would be more appropriate
4) Ideally, most of your opponents have shown weakness (i.e. checked)
5) You need to know that the guys you're up against are able to drop all but the top 2 flushes when you bet into them; if they're the sort to call more or less any flush, or you suspect they might be, don't waste your time.
6) An additional caveat - the play is MUCH stronger if you have some backup. In this case, you have the straight, which is going to count as "backup" if someone comes along with a set; he STILL needs to hit to win, whereas with just the bare ace you're losing if you get called down and/or give up on the hand. The classic situation is holding top set plus the bare ace on a one-suited flop; you want to bet the pot here in most cases, no-one's raising (except for maniacs) and if someone calls they either have a low set (and are thus dominated) or 2nd or 3rd nut flush and will kindly call/check down giving you free cards to hit your 35% or so "get out clause" boat. Fold equity plus free cards for the boat makes it a very good play.

All said, there's a time and a place for bare ace bluffs, and in a game where bluffs are common and lots of players will take a look in the early streets, it can take some nerve because the pots in PLO can get very big very quick. If you don't have anything but a bluff and a prayer it can take a lot of balls to make the big bet on the turn or river with nought but the ace!

I would file this away under "good plays to remember once I get to 100/200/400 buyins" because at PLO25 I just think you'll get called down too frequently bluffing the bare ace. If you find a situation where most or all of points 1)-6) apply, I guess it's always worth a shot though!

Monk
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