Don't know where to start...

[ddss6_99]

I'm not very good at the math aspect of poker, and I was wondering if anyone could help me out. How would one go about calculating whether a call is +EV or not in a probable coin flip situation like the one below. Would the math be the same if hero had AK instead of 88. If not, how would you go about calculating that?

#Game No : 1722264596
***** Hand History for Game 1722264596 *****
NL Hold'em $10 Buy-in + $1 Entry Fee Trny:10308655 Level:8 Blinds(250/500)
Table Table 11537 (Real Money)
Seat 7 is the button
Total number of players : 4
Seat 2: norrisbruce ( $2380 )
Seat 7: jlk2282 ( $335 )
Seat 1: lostanddrunk ( $2195 )
Seat 9: G_Funk3 ( $3090 )
Trny:10308655 Level:8
Blinds(250/500)
** Dealing down cards **
Dealt to norrisbruce [ 8 /images/graemlins/club.gif 8 /images/graemlins/spade.gif ]
norrisbruce raises [1000].
jlk2282 folds.
G_Funk3 folds.
lostanddrunk is all-In [1695]
norrisbruce calls [1195].
** Dealing Flop ** [ 3 /images/graemlins/club.gif, A /images/graemlins/club.gif, J /images/graemlins/club.gif ]
** Dealing Turn ** [ Q /images/graemlins/club.gif ]
** Dealing River ** [ A /images/graemlins/spade.gif ]

[MickeyHoldem]

OK... you called 1195 into a 3400 pot... you were getting 2.85 to 1 on your money ... what range of hands is your opponent going to push in this position??

If he's only going to push with high pockets... lets assume 99's up (worst case)... by poker stove your equity is about 19% and calling was -EV.

But if he pushes with these high pockets and just AKs + AKo as well, then by pokerstove your equity is about 30%... so calling is +EV... as you add more hands that he is likely to push with your EV goes up.

You need to win about 26% (1/3.85) of the time to make calling +EV

In a ring game, calling here is correct... as for a tourney... there are many other things to be considered, that I delibrately ignored... stack sizes, payouts, effect of losing crippling your stack, etc.

[ddss6_99]

[ QUOTE ]
OK... you called 1195 into a 3400 pot... you were getting 2.85 to 1 on your money ... what range of hands is your opponent going to push in this position??

If he's only going to push with high pockets... lets assume 99's up (worst case)... by poker stove your equity is about 19% and calling was -EV.

But if he pushes with these high pockets and just AKs + AKo as well, then by pokerstove your equity is about 30%... so calling is +EV... as you add more hands that he is likely to push with your EV goes up.

You need to win about 26% (1/3.85) of the time to make calling +EV

In a ring game, calling here is correct... as for a tourney... there are many other things to be considered, that I delibrately ignored... stack sizes, payouts, effect of losing crippling your stack, etc.

[/ QUOTE ]

Ok, I think I understand what you're saying. Just a few questions though. I'm confused about the equity part. What makes 30% equity +EV as opposed to 19% being -EV. I always thought you needed 50%+ for it to be +EV.
Another question. You said I have to win 26% of the time (1/3.85) to make calling +EV. How did you figure that out. What's the 3.85 represent? Thanks for the help.

[elitegimp]

[ QUOTE ]
[ QUOTE ]
OK... you called 1195 into a 3400 pot... you were getting 2.85 to 1 on your money ... what range of hands is your opponent going to push in this position??

If he's only going to push with high pockets... lets assume 99's up (worst case)... by poker stove your equity is about 19% and calling was -EV.

But if he pushes with these high pockets and just AKs + AKo as well, then by pokerstove your equity is about 30%... so calling is +EV... as you add more hands that he is likely to push with your EV goes up.

You need to win about 26% (1/3.85) of the time to make calling +EV

In a ring game, calling here is correct... as for a tourney... there are many other things to be considered, that I delibrately ignored... stack sizes, payouts, effect of losing crippling your stack, etc.

[/ QUOTE ]

Ok, I think I understand what you're saying. Just a few questions though. I'm confused about the equity part. What makes 30% equity +EV as opposed to 19% being -EV. I always thought you needed 50%+ for it to be +EV.
Another question. You said I have to win 26% of the time (1/3.85) to make calling +EV. How did you figure that out. What's the 3.85 represent? Thanks for the help.

[/ QUOTE ]

Once the decision is for you to call all-in or not, you look at how big the pot is at that point relative to how much you have to call. As previously mentioned, you have to call 1195 to win the 3400 that is already in the pot.

You don't need to win 50% of the time for this to be +EV: Suppose you win 1/3 of the time: then your EV is (1/3)(3400) [because 1/3 of the time you end up with 3400 more than if you just folded] + (2/3)(-1195) [because 2/3 of the time you end up with 1195 less than if you just folded]. This turns out to be 1133 - 797 = 336. So if you are in this situation thousands of times (in the long-run), you expect to win $336 per time you call.

In fact, you can exactly calculate the break-even point by finding the probabality 'p' such that if you win p of the time, your EV is 0. To set this up, you say your EV is p*3400 + (1-p)(-1195) = 0, so p(3400+1195) = 1195 => p=1195/(3400+1195) which is 0.26, or 1 in 3.85.