POLL: Odds for chasing backdoor flush

[ScottC]

Is it proper to consider 5:1 odds on the flop to make a four flush on the turn if you believe the pot will then offer you 5:1 for the river?

Obviously, you have to consider higher flushes, board pairs to boats, and if you are at a loose table or not. But do the general odds make sense if all the other (rather intangible) variables line up?

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[spamuell]

Don't you think it would be more productive to just ask this than to make a poll? Anyway the answer is no, 5:1 on the flop is not enough to chase a backdoor flush draw alone, you need about 30:1. This is explained in SSH.

[ScottC]

[ QUOTE ]
Don't you think it would be more productive to just ask this than to make a poll?

[/ QUOTE ]This gives people an option to type a response or answer using the poll if they don't have the time or inclination to type a response.
[ QUOTE ]
Anyway the answer is no, 5:1 on the flop is not enough to chase a backdoor flush draw alone, you need about 30:1. This is explained in SSH.

[/ QUOTE ]Thanks, I'll check that out. SSH = Small Stakes Hold'em by Sklansky, right?

[topout]

Backdoor flush is about 3.5%.

topout

[nsdjoe]

bear in mind the 30:1 number is just for the backdoor flush alone. if you have other outs that will or could give you the best hand, you have additional partial and/or full outs and your odds improve.

[Girchuck]

There is something wrong with your math.
Suppose that you have A [img]/images/graemlins/club.gif[/img] and there are two clubs on the flop. There are 4SB in the pot, someone bets, and you are getting 5:1 odds. Supposing that everyone else folds and you call there are now 3BB in the pot. To get to 5:1 odds on the turn draw you need two more calls on the flop.
Let us say that at the turn you are somehow getting 5:1 odds to see river. If another club falls on the turn, you have the odds to draw to the fourth club on the river, but the EV of the draw is between 0 and 1 BB, unless some dead money follow you to the river, improving your actual odds.
If another club does not fall, you lose an SB
Lets calculate your overall EV
10 times out of 47 a 3rd club falls and at the maximum you draw at +1BB advantage for 10BB out of 47 gain
37 times out of 47, no club falls, and you lose an SB for a -18.5BB out of 47 loss.
The maximum advantage your draw provides you does not offset the times you draw to the third club and miss.

This calculation assumes perfect conditions for your draw, i.e nut flush draw and very simple action without possibility of a raise.

[adamstewart]

As per SSH, a backdoor flush draw is worth an additional 1.5 outs.

Include this in your pot odds calculations on the flop.

Then make sure to recalculate on the turn, with the new turn card accordingly.



For those interested, the value of 1.5 outs does not exactly correspond to the actual mathematical odds of completing a backdoor door flush with two cards to come. Instead, it has been adjusted to account for the fact that if the turn card is not of our suit of interest, we can fold and/or immediately remove that backdoor draw from further odds calculations.



Adam

[ckessel]

You need 25:1 at the flop to go strictly on a backdoor flush.

A backdoor flush tends to help out overcards or gutshots. It's almost never sufficient reason in and of itself to call the flop.