Effective Odds

[triplc]

Hi all,

Just want to make sure my thinking is correct on effective odds. Suppose this scenario plays out this way.

Four people see a flop for a buck apiece in a $1/$2 game (hence, there's $4 in the pot pre-flop). The flop gives me four to the nut flush, and I am last to act.

The opener bets out ($1), the other two fold and it is to me. At this moment, I have 5-to-1 pot odds and a flush draw is 2.86-to-1 (Please correct if I have this wrong) if I am playing to the river, or 5.23 to 1 to see the turn. However, if I don't hit the flush on the turn, I am likely to have to call a $2 bet to see the river, which gives me effective odds of 7-to-3.

Please tell me if the following is correct.

I cannot call this bet because my pot odds are insufficient to see the turn, and my effecive odds are insufficient to go all the way to the river.

Would this change if there were $5 in the original pot (which gives 6-to-1 pot odds (good for a call), but 8-to-3 effective odds (close but not quite there)). In this case, my guess would be that you see the turn but not the river if the flush doesn't fall.

Thanks.

CCC

[pudley4]

[ QUOTE ]
or 5.23 to 1 to see the turn

[/ QUOTE ]

This is slightly incorrect. You have 9 of 47 cards to help on the turn, so you are 38-9, or 4.22-1 against hitting. Therefore you can call the flop bet, getting 5-1 on your call.

You are also slightly less than 2-1 against hitting by the river, so even if you look at the total it will cost you (7-3), you are getting good enough odds to call to the river.

Finally, effective odds are better used when you are unlikely to improve. For example:

You have A /images/graemlins/diamond.gifA /images/graemlins/heart.gif. Flop is T /images/graemlins/club.gif9 /images/graemlins/club.gif8 /images/graemlins/club.gif, and your opponent bets into you. Now, you might be ahead, but if you are it's likely your opponent has many outs against you. If you are behind (to a straight or flush), you are very unlikely to catch up. In a case like this, you'll want to look at the effective odds you're getting (probably 9-5, assuming you raised preflop, and are heads-up on the flop)

[Bozeman]

Odds:1 = (prob of missing)/(prob of hitting) = 1/(prob of hitting) - 1 !=(not equal) (1/prob of hitting)

Care to try again after correcting this?

Craig

[triplc]

Sure! And thanks for the clarification, Bozeman.

Thanks to pudley4 also in the above post...

So...the odds for the turn would be 9/38 or 4.22 to 1
The odds for the river alone would be 9/37 or 4.11 to 1
The odds for getting it on the turn or river would be calculated as follows.

P(A or B) = P(A) + P(B) - P(A and B) which is
9/47 + 9/46 - (9/47 * 9/46) ~= .3496 so the odds would be

.3496/(1-.3496) = 1.86 to 1.

so...lets say the pot has 3 callers at a dollar apiece and the I have my flush draw after flop and the first to act opens for $1 (Pot has 4 bucks in it). My pot odds are now 4-to-1 to call the flop bet, assuming the other guy folds to his bet. This is close but techically not enough for a call (using pot odds alone).

however, my effective odds would be 6-to-3 (accounting for my $1 flop bet and $2 river bet and the $4 in the pot now and the $2 he will presumably bet on the turn). Thus, does it make sense for me to call once middle position has folded because my odds to hit are 1.86, while I am getting 2-to-1 effective odds to call (slightly the best of it), even though I am getting slightly the worst of it (4.22 to 1 againt 4-to-1 pot odds) on the flop bet. I am thinking that I'm going to the river on this one. I think this also points out the importance of position, as I can calculate this with confidence in this case because I am acting last.

Thanks again for the help, folks, and I await your feedback.

CCC

[triplc]

[ QUOTE ]
Finally, effective odds are better used when you are unlikely to improve. For example:

You have A A . Flop is T 9 8 , and your opponent bets into you. Now, you might be ahead, but if you are it's likely your opponent has many outs against you. If you are behind (to a straight or flush), you are very unlikely to catch up. In a case like this, you'll want to look at the effective odds you're getting (probably 9-5, assuming you raised preflop, and are heads-up on the flop)

[/ QUOTE ]

Just to clarify, I am looking at the effective odds to determine, in this case, not whether I am going to draw out on my opponent (which is extremely unlikely, as you said), but instead to determine if I should continue based upon the percentage of times that I am going to win the hand.

In other words...there are almost no effective odds that will allow me to call this if I am %100 sure that my opponent has the flush or straight (certainly not heads up). But if I know this player to bluff a lot with scary boards, or would only play certain hands in EP which might give him only a couple hands that have me beat (lets say AKc, AQc), and a few that are decent draws then if I think I will win this hand a little better than 1/3 of the time (5/14 given the 9-to-5 odds from the example), then I have positive EV and should go ahead and call.

Is this what you are saying?

[pudley4]

[ QUOTE ]
[ QUOTE ]
Finally, effective odds are better used when you are unlikely to improve. For example:

You have A A . Flop is T 9 8 , and your opponent bets into you. Now, you might be ahead, but if you are it's likely your opponent has many outs against you. If you are behind (to a straight or flush), you are very unlikely to catch up. In a case like this, you'll want to look at the effective odds you're getting (probably 9-5, assuming you raised preflop, and are heads-up on the flop)

[/ QUOTE ]

Just to clarify, I am looking at the effective odds to determine, in this case, not whether I am going to draw out on my opponent (which is extremely unlikely, as you said), but instead to determine if I should continue based upon the percentage of times that I am going to win the hand.

In other words...there are almost no effective odds that will allow me to call this if I am %100 sure that my opponent has the flush or straight (certainly not heads up). But if I know this player to bluff a lot with scary boards, or would only play certain hands in EP which might give him only a couple hands that have me beat (lets say AKc, AQc), and a few that are decent draws then if I think I will win this hand a little better than 1/3 of the time (5/14 given the 9-to-5 odds from the example), then I have positive EV and should go ahead and call.

Is this what you are saying?


[/ QUOTE ]

Exactly.

[pudley4]

When you think you are behind (as in this scenario), you also need to look at implied odds (the extra bets you will win when you make your hand).

In your example, you are only getting 4-1 on your flop call, which technically isn't enough to continue. However, if you hit on the turn, you'll almost surely get more bets from your opponent (anywhere from 1-3 BB). So your implied odds are anywhere from 6-1 up to 10-1, making the turn call automatic.