[binions]

[ QUOTE ]
O yeah, one other thing, since stack-to-pot ratios are all the rage these days. In the original situation (8/9 draw), say that your opponent makes a pot sized bet on the flop. Then the formula simplifies to

(spr-1)/(spr+5)

where spr is the stack-to-pot ratio. Since we have all read PNL [img]/images/graemlins/smile.gif[/img] and we are all keeping track of the spr, this is very easy to calculate quickly.



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So, assume 100 in the pot going into the flop, villain has 800 left and you cover. Effective SPR is 8:1. He bets pot, and you have a 2:1 draw if you see both cards.

SPR -1 / SPR +5 = 7/13 so he needs to fold 7/13 of the time to a push to break even. Let's see if it works:

7 times he folds and you win 200 = +1400

6 times we get called. We win 2 and lose 4.
2 times you win 900 = +1800
4 times you lose 800 = -3200

Yep. 3200 - 3200 = 0.

Good work. So, we know the shortcut when we have 33% equity and villain bets pot. How does the SPR -1 / SPR +5 formula adjust when:

You have 20%, 25%, 40%, 50% equity and villain bets pot?

You have 20%, 25%, 33%, 40% and 50% equity and villain bets 2/3 pot.

Thanks