Omaha Hi - correct odds?

After reading Ciaffone's fine book on Omaha there is something I don't understand...

Bob says that the correct way to figure outs in a hand is to use your # of out cards, say 13, with TWO TO COME you take that number ie 13...add another 3/4 of 13 together for the river and that is the correct way to figure the number of outs you TRULY have (if I understand him correctly).

So he gives an example of a set against the nut straight. He says the set has 15 outs with 2 to come. There are TEN cards to improve a set, period. With 41 unseen cards that's roughly 3-1 against. I don't understand WHERE he is getting the additional 5 outs.

Can someone help please?

[Jimbo]

I do not see where you come up with "There are TEN cards to improve a set, period." On the flop there are 7 cards to fill up with on the turn. After the turn there "may be" now 10 cards to fill up with. You only use the cards in your hand plus the board to compute outs. Three on board, four in your hand with 45 unknown cards. After the turn there are four on the board with four in your hand and 44 unknown cards. You will fill up approximately 35% of the time when you flop a set.

Jimbo

Jimbo, first I want thank you for your post.

Regardless if it's omaha or holdem, you flop a set (with no other redraw) and with 2 to come, you have on the turn 7 outs and pick up 3 more going to the river.

How Bob gets 15 outs with 2 to come is a mystery to me.

With Omaha, on the flop you have 41 unseen cards, 7 to improve against a MADE straight or flush. 7 devided by 41 should be the right price, anything more and overlay. On the turn if the hand is not yet improved, you pick up 3 more outs (10\40) roughly 3-1 against. How does he come up with 15 outs with 2 to come??

What am I missing? Thank you.

[Jimbo]

I have no idea what he is implying. Perhaps if you post the entire phrase along with any board/card examples he offers to go with this statement we can figure it out together. You are still using 41 cards instead of 45, you cannot count the opponents hand in your computations because in real life you do not "absolutley know" their hand.

Jimbo

[Bozeman]

Jill,

He is presumably talking about when all the money goes in on the flop, and computing equivalent one card outs for the actual two card draw. That is, your chance of improving by the river is approximately equal to your "effective outs"/unseen cards. For the set, if you "know" that you are facing a made straight, there are 4+3+2=9 seen cards and 43 unseen cards. Assuming all your outs are live, you fail to improve 36/43*32/42=64%, so you make your hand 36% of the time. Depending on how many unseen cards you count, this is about .36*43=15.5 "effective outs". How exactly Bob Ciaffone does this calculation I am not familiar with, but presumably he adds the river outs to the turn outs, which are discounted by (1-fraction of river outs) so that you don't double count hands that are "made" twice.

Does this make any sense?
Craig

[Phat Mack]

I believe he my be trying to give the reader a way to calculate more accurate odds during game conditions by removing duplicates.

Let's say that you have TTxx, and the flop comes T98. You know you are against a made straight, what are the odds of filling up? There's 45 unseen cards. If ypou say to yourself, "I have 7 outs on 4th street and if I miss, I have 10 outs on 5th street," then you will figure 7/45 + 10/44 = +/- 17/44.5 = =/- .38.

The problem with this approach is that 4th st./5th st. combinations such as 98 will be double counted, once as 9x and once as x8. So your true odds, or outs, must be tweeked downward. I think what Bob might be doing is giving a mental shortcut for doing the tweeking at the table, but I am not positive. What page was this on? I'll take a look and see if I can figure it out.

Thanks guys for your help and insight. Bob's example is on page 88 of "Omaha Holdem Poker".

I'm confusing Jimbo I think, sorry. Phat Mack seems to be saying what Ciaffone is saying. Altho I still don't understand, forgive please.

MY problem is that for example, with a set against a hand with no redraw, ultimately he comes up with "15" outs! Since there are only 10 possible cards to improve the set BY the river how can this be?

The additional 5 cards that he comes up with are obviously important. That's where I'm confused.

Also, in the same book for Omaha Hi, there is I believe ONLY ONE draw, the 20 way straight draw (17 is close) that is a favorite over a set. I am very surprised that in OM Hi a set is that strong.

Having said that, if you have top set against 2 other players ONLY (!), one with a flush draw, one with ONLY a 13 way straight draw, the set looks like a long term BIG looser in Om Hi. Unless you can get it head up on the flop, long term I don't see how top set can be profitable. Without a redraw, 2-3 ways, a set in OM Hi looks like financial suicide.

I would appreciate ANY comments on any of the above. And thanks for your input. Jill.

[Greg (FossilMan)]

Bob is giving you an equivalent.

With a set, your 7 outs on the turn plus 10 outs on the river is equivalent to some other draw that has 15 outs once.

Notice that a bunch of folks have posted that the set will fill up about 1/3 of the time. Also notice that 15 outs once is also an event that happens about 1/3 of the time.

Once you do Bob's calculations for the number of "outs" you have, and divide it by the number of unseen cards, you are estimating your chances of making your hand that has two chances to hit. That's all.

Later, Greg Raymer (FossilMan)

[Graham]

Jill: "Having said that, if you have top set against 2 other players ONLY (!), one with a flush draw, one with ONLY a 13 way straight draw, the set looks like a long term BIG looser in Om Hi. Unless you can get it head up on the flop, long term I don't see how top set can be profitable. Without a redraw, 2-3 ways, a set in OM Hi looks like financial suicide."

For some reason I'm trawling the PL/NL Archives...and , since noone responded and I've been playing a bunch of PLO recently.

Your thinking is correct: top set with little or no backup is often toast multiway past the flop. So how do you deal with that and get the situation you want when you flop the set many-handed..?

The answer is to play as hard as possible on the flop to flush out (no pun intended) the weaker draws and hopefully either take it down right then or go heads-up vs one draw who is likely an underdog to you. The draw in the hands of a strong player has leverage, though, since you don't know which scare cards to believe and are susceptible to bluffs. So I am usually happy to win on the flop with a dry set, but prefer to get called if I have a back-up draw (flush, straight, whatever) as I then have more knowledge of what cards to be scared of and welcome some of them. But you just can't let the raggedy draws hang around if many see the flop. If a strong draw wants to play with me, sure, but he/she is going to pay to play. I'd often slow the flop betting when it's going to be heads-up to teh turn, then charge the draw again on the turn if that card didn't scare me too much.

What if you play your set hard on the flop and get called in a few spots? It's still cool; call it value betting. Except, as I said, you might get put to a test on the turn when a draw gets there. Then you have to assume you're behind and play the odds when it's very likely at least someone hit.

A time I might be very concerned with top set on the flop is if teh board is very drawy, eg QsJc3s, and lots of frantic action before it gets to you (you are playing in good position aren't you..!?!..). I don't think it'd be too bad either way, to play on or not, but sometimes I don't feel like gambling and splashing my chips around when a set is unlikely to be more than chum bait by the river. [img]/forums/images/icons/tongue.gif[/img]

Hopefully my thinking isn't too far off the mark. I won't claim to be an expert.

sorry, rambled into a longer than intended post that'll probably never be read...must be a slow morning for me...where's that coffee..?..

PS; for anyone who's go this far, Greg's got it withe BC's outs example. It gives the equivalent number of outs with hypothetically one card to come; makes the sums easier instead of dealing wih 2 cards to come. Bob's correct in the book but it's just initially confusing.

[Phat Mack]

</font><blockquote><font class="small">In reply to:</font><hr />
The answer is to play as hard as possible on the flop to flush out (no pun intended) the weaker draws and hopefully either take it down right then or go heads-up vs one draw who is likely an underdog to you.

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First of all, let me state that I am not prescribing play for top set, one way or another. But nobody will lay down a stong draw to a bet on the flop, and if the strong draws are going to play, why not invite the weak draws to come along with them? If you're up against nut flush draw and a 13 out straight draw, the second nut flush draw shouldn't be a burden.