It depends, bigtime. Have a look at my front page on post-flop play in PLO (and also the one on PLO betting strategies) for some handy hints on draws and outs.

It also depends bigtime, obviously, on how many opponents are in (!) and what hands they likely have. A 15-outer to the nut flush and boat (i.e. top set and top flush draw) on a straight board is totally annhialating the made straight on the flop; you win about two thirds of the time with the drawing hand and thus you want to pound that fucker and get it all in ASAP.

In terms of flops, as a rule it's probably reasonable to call with around 10 NUT outs with two cards to come for your stack. A nut flush draw with a gutshot straight wins enough to be able to call off a pot-sized all in on the flop versus a made top set. Your problems arrive when you realise that some of your outs might not be clean (i.e. you have the K-high flush and a gutshot; will your flush be good? Does he have the set? Do you have any other way to win? There's lots of intangibles and it takes a nice "feel" for the game to always make the right decision; I certainly still screw these close calls up now and again, but it's rare for the mistake to be a catastrophic one as long as you make sure you're liable to win a decent % of the time even if your read is wrong; this is why making a crappy call with a draw is much, much better than making a misjudgement with a potentially dominated hand like middle set). However, to simplify things and give you a decent reference point, the following situation would be a decent call with the gutshot and nut straight draw:

Flop: Q[h] K[h] 5[s]

You hold A[h] T[s] 9[s] 5[h]

Your opponent moves all in for a $120 bet into the $120 pot.

Calling is fine - if he has the top set with no cards that "block" yoru draws, you win right round about 40% of the time, would you believe. If he has two blocking cards to your flush, you win 36% or so. If you change the 5 in your hand to a 4 and give him a blocking card to your straight as well as two flush blockers (i.e. he has K[s] K[d] J[h] 6[h]) you still win 34% of the time. You need 33.33% to draw level (yeah, obviously you know that, not meaning to be condescending) so your call here will pretty much always be fine.

On the turn, you want to be looking at 17 or 18 nut outs to have a certain call, because your opponent might have some of them covered in his hand. Once you both turn your hands over, there's 45 cards left in the deck, so you need 16 outs to be +EV. Factor in the possibility your oppo has some of your outs (possibly) in his hand, I'd prefer to have 18 or so, for a turn all in. Of course, if there's a few chips left to bet on the end, you can call with fewer outs on the turn, knowing he won't fold a made hand for such a small amount BUT knowing that you will fold if you DON'T hit your outs (this is a very important caveat - for your implied odds to be good, you need to have no negative implied odds, that is, you can't put another $ in if you miss).

There is also the turn possibility (or flop possibility) that you don't know for sure that you're behind, or at least that you don't have additional "hidden) outs. That is, although you may only have ten clean outs in the "worst case" scenario (i.e. your opponent has the current nuts), there's always a chance that he might be pushing a draw, or pushing two-pair when you thought he had a set, and thus that you have some additional outs you hadn't considered. That possibility can swing a call your way.

Consider this - you have AA56 with a suited ace. Flop brings J82 with two of your suit. Your solid opponent moves all in immediately on the flop for a pot-sized bet. Now, if we assume he has a set, you're probably a shade -EV to call, with the possibility he might have some of your flush or ace outs. However, he might have top two, against which you now have a lot of extra outs (2 for higher two pair, any running pair for higher two pair), he might be pushing a monster draw (i.e. 79TJ with a flush draw) and thus you might actually be ahead. Sure, the set seems marginally most likely (if we know this guy won't push an overpair) but the other possibilities open up a world of extra potential outs and so for one pot bet on that flop it's an easy call.

To be a favourite on the flop with a draw you need about 18 outs (minimum) but realistically to shove all in with a draw after you're re-raised you need to have basically the perfect omaha draw (20 or 21 outs) because of the possibility your opponent has some of your outs. Even then, you're not usually a big favourite with a draw and thus should generally just call along unless you have some sort of made features in your hand already. The only drawing hand which is a big favourite over a nut hand on the flop is the situation I described before - set and flush draw vs made straight. Any time you have the top set and a big flush draw, or nut flush draw and middle set, you want to be shovelling in chips on a straight board.

In terms of calling a pot-sized raise on the flop with a draw when it's NOT all in, I like 10 outs. Implied odds makes it a more than useful call, even if you know your man is going to bet the turn for sure if it's safe. In small pots when there's LOTS of money left to bet, I will often call a pot bet with a bare flush draw or open-ender, especially if it's well-hidden and especially if there's passive players to act behind me who have a good chance of putting in a call to swell the pot if I hit. However, if the bet is a substantial amount of my stack, and I only have a straight or flush draw, and/or there's little likelihood of extra calls or a possible check-raiser hiding downwind, I drop those 7 and 8 card draws.

It just takes a bit of experience and a bit of feel, usually as long as you keep studying the odds in different situations and show a genuine intellectual interest in deconstructing the mechanics of a few different common hands, you'll make the right decisions far more often than not. Also, don't beat yourself up TOO much for making the odd poor draw call; although it loses you money, it's surprisingly not the biggest leak in PLO; people who overplay weak made hands (low sets, straights on a draw-heavy board, re-raising AAxx preflop when there's lots of money left to bet etc.) throw a lot more easy money away than people who call draws that are a few % -EV.

Hope this helps!

Monk
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