Omaha Odds/Probabilities Question...

[Deveroast78]

I know how to figure odds against making a hand on the turn in Omaha on the turn: X:45, where x equals no. of outs.

I can figure the same going into the river: X:44.

I am not sure, however, how to figure these three scenarios:

1) With a 13-out wrap draw on the flop, what are the odds against and percentage chance for hitting your straight with two cards to come (turn and river), not expressed separately, but as one ratio or percentage?

2) With a flush draw, one COULD consider there to only be 8 pure outs, as when the flop comes Kh-Th-7s, the 7h on the turn could make someone a full house. Similarly, if the turn doesn't pair the board, one could argue there are only 7 outs going into the river for the same reason. So how do you figure the odds against and percentage for 8 outs post-flop and 7 outs after the turn?

3) If you were to flop a set, you have 7 outs on the flop to make a full house or quads, then a redraw with 10 outs if the board does not pair on the turn. How do you figure the odds against and percentage for this scenario?

Please explain (briefly) how these calculations are done. I use the 4-2 rule for hold'em to figure odds on the fly, but with four downcards and different types of draws, I'm not sure if this would work for Omaha. Thank you all in advance for your help.

[BruceZ]

[ QUOTE ]
1) With a 13-out wrap draw on the flop, what are the odds against and percentage chance for hitting your straight with two cards to come (turn and river), not expressed separately, but as one ratio or percentage?

[/ QUOTE ]

3 methods:

1 - (32/45 * 31/44) =~ 49.9%

OR

13/45 + (32/45 * 13/44) =~ 49.9%

OR

(13/45)*2 - (13/45 * 12/44) =~ 49.9%

Odds: 1/0.499 - 1 =~ 1.004-to-1 against.

This post explains these 3 methods in detail for a 9-out flush draw in Texas Hold'em. Everything is the same except for the number of outs, 47 cards remaining after the flop, and 46 cards after the turn.


[ QUOTE ]
2) With a flush draw, one COULD consider there to only be 8 pure outs, as when the flop comes Kh-Th-7s, the 7h on the turn could make someone a full house. Similarly, if the turn doesn't pair the board, one could argue there are only 7 outs going into the river for the same reason. So how do you figure the odds against and percentage for 8 outs post-flop and 7 outs after the turn?

[/ QUOTE ]

1 - (37/45 * 37/44) =~ 30.9%

OR

8/45 + (37/45 * 7/44) =~ 30.9%

Odds: 1/0.309 - 1 =~ 2.24-to-1 against.

Refer to the first 2 methods used for question 1 above.


[ QUOTE ]
3) If you were to flop a set, you have 7 outs on the flop to make a full house or quads, then a redraw with 10 outs if the board does not pair on the turn. How do you figure the odds against and percentage for this scenario?

[/ QUOTE ]

Do this just like question 2 above except for 7 and 10 outs. I'll tell you if you got it right.

[Deveroast78]

Something like 34.7% for or 1.88:1 against?

Also, can rule of four and two be used for a ballpark figure when I'm in the middle of an Omaha hand here if number of outs on turn and river are identical? 13 outs times 4 is 52, about 2% off...

[BruceZ]

[ QUOTE ]
Something like 34.7% for or 1.88:1 against?

[/ QUOTE ]

That's right. Did you compute it yourself, or did you look it up?


[ QUOTE ]
Also, can rule of four and two be used for a ballpark figure when I'm in the middle of an Omaha hand here if number of outs on turn and river are identical? 13 outs times 4 is 52, about 2% off...

[/ QUOTE ]

The formulas I gave you give the exact numbers, so you can compare them to the 4/2 numbers, and decide for yourself if they are sufficiently accurate for your purposes. I've never had any use for the 4/2 rule myself, mainly because I want odds rather than percentages, and I don't have any problem memorizing a few numbers for the required pot odds to see the turn. The numbers for 2 cards to come are not that useful unless you don't have to pay 2 bets to see the river.

[Deveroast78]

I just used a standard calculator. Thanks for the help, it's much appreciated. As far as odds v. percent, percent works easier for me, I just figure what % of the pot I need to call for pot odds, though I should probably start thinking in terms of odds since it is more commonly used.