Pre & post-flop odds

[pedigreechump6]

Hi, just wondering if anyone could help me with this....

Say I was playing a 4 hand game of poker and I knew all of the four hands, then how do the odds change from pre-flop to post-flop?

For example, say the hands are JcJd, 8s5c, Ah5h, and 5d2c, then the probabilities of winning at the end(according to pokerstove) are 53.325%, 10.614%, 28.753%, and 7.307%

What I want to know is what are the expected probabilities of each hand after the flop?

I realise that there are over 13,000 combinations of flop, but theoretically will the probabilities change on average or will they stay the same?

Thanks in advance for any help...

[Masterplan]

after thinking long and hard about your question i think you're asking if the probabilities change for any 3 random cards on the flop ... and not any 3 specific cards ... which would just be silly.
thankfully my poker calc can do this.

HAND STAGE: Flop

PLAYER CARDS % Win % Loss % Draw
__________________________________________________ ________
User JC JD 76.166% 23.834% 0.0%
1 8S 5C 2.692% 97.308% 0.0%
2 AH 5H 18.569% 81.431% 0.0%
3 5D 2C 2.573% 97.427% 0.0%

as compared to

HAND STAGE: Showdown

PLAYER CARDS % Win % Loss % Draw
__________________________________________________ ________
User JC JD 53.354% 46.472% 0.174%
1 8S 5C 10.063% 88.09% 1.847%
2 AH 5H 28.044% 70.109% 1.847%
3 5D 2C 6.692% 91.461% 1.847%

[chelskired]

Originally Posted by pedigreechump6

Hi, just wondering if anyone could help me with this....

Say I was playing a 4 hand game of poker and I knew all of the four hands, then how do the odds change from pre-flop to post-flop?

For example, say the hands are JcJd, 8s5c, Ah5h, and 5d2c, then the probabilities of winning at the end(according to pokerstove) are 53.325%, 10.614%, 28.753%, and 7.307%

What I want to know is what are the expected probabilities of each hand after the flop?

I realise that there are over 13,000 combinations of flop, but theoretically will the probabilities change on average or will they stay the same?

Thanks in advance for any help...

As there is no flop that can compliment all 4 hands to the same degree, the odds will have too change. Won't they? Or am I mis-understanding the question?

[Masterplan]

he's asking the arbitrary odds given an arbitrary flop ... ie ... 3 less cards to come.
i was thinking ... what a stupid question for so long before realising this

[chelskired]

Originally Posted by Masterplan

he's asking the arbitrary odds given an arbitrary flop ... ie ... 3 less cards to come.
i was thinking ... what a stupid question for so long before realising this

Phew Thank god for that, 1st Sunday for months with no hangover and for a minute wished I had 1

[pedigreechump6]

Masterplan, that is exactly what I was after! Thanks so much!

Sorry for not making the question clear enough but it was hard to put into words......for me at least.

Out of interest, what calculator are you using? Is it a home-made one or one you purchased?

[slapdash]

The odds are exactly the same.

The chance of winning pre-flop is the average, over all flops, of the chance
of winning post-flop.

I can't quite figure out what your calculator is calculating, Masterplan?

[slapdash]

Ah, I think it's probably calculating the probability of winning if there are
only two board cards, and everybody has to make do with only four cards
to make a poker hand ... so flushes, straights and full houses become
impossible?

[Masterplan]

no, i think its the probability of winning based on just the 5 board cards, and not the turn and river. so straights and flushes are still possible, but not probable

[pedigreechump6]

slapdash, if this is the case, would you say that the chance of winning pre-turn is the avergae, over all turn cards, of the chance of winning post turn?

This is definitely not the case as I have tried this manually using my calculator inputing each of the 44 possible turn cards and the probabilities DO change.

So surely a similar outcome would happen for the flop?

[slapdash]

Originally Posted by Masterplan

no, i think its the probability of winning based on just the 5 board cards, and not the turn and river. so straights and flushes are still possible, but not probable

Not sure I understand. Which 5 board cards, if there's no turn or river?

[slapdash]

Originally Posted by pedigreechump6

slapdash, if this is the case, would you say that the chance of winning pre-turn is the avergae, over all turn cards, of the chance of winning post turn?

Yes.

This is definitely not the case as I have tried this manually using my calculator inputing each of the 44 possible turn cards and the probabilities DO change.

So surely a similar outcome would happen for the flop?

44 possible turn cards? After the flop, an odd number of cards have been
dealt, so there are an odd number of possible turn cards, however many
players there are.

Can you describe exactly what you calculated?

[slapdash]

Originally Posted by slapdash

Not sure I understand. Which 5 board cards, if there's no turn or river?

I think I understand now. You're calculating the probability that you will be
ahead after the flop?

[pedigreechump6]

sorry about that slapdash, I meant 41 possible turn cards

basically i used my calculator and inputted 4 hands and the flop, then I put in each of the remaining 41 cards as a possible turn card and recorded the probability it gave of each hand winning. On average the probabilities do change after the turn.

[pedigreechump6]

btw masterplan, which calculator do you use?

I know I have already asked but i guess you might have missed it...

[slapdash]

Well, to calculate the probability of winning after the flop, you count the
number of turn/river combinations where you win and divide by the total
number of turn/river combinations (which is 41*40 = 1640).

To calculate the probability of winning after the turn, you count the number
of rivers where you win and divide by the total number of rivers (which is
40).

If you take the average of this probability over all possible turns, you just
add up all the individual probabilities and divide by 41 (the number of
possible turns). But this will give you the total number of winning turn/river
combinations divided by 40*41 ... which is exactly the same as what you
get from the pre-turn calculation.

[pedigreechump6]

slapdash, your logic is unquestionable, and after looking at my results more carefully I can confirm that you are correct with regards to the pre and post-turn scenario.

So this is the same with the flop then? If so, I wonder what masterplan's calculator is telling us?

It's a shame I cant test this without having to input every flop combination manually....

[Masterplan]

i use a java based calc called PokerOdds2.

[chelskired]

Originally Posted by pedigreechump6

slapdash, your logic is unquestionable, and after looking at my results more carefully I can confirm that you are correct with regards to the pre and post-turn scenario.

So this is the same with the flop then? If so, I wonder what masterplan's calculator is telling us?

It's a shame I cant test this without having to input every flop combination manually....

Try http://www.calculatem.com/index_g.ht...calculator&g=1 mate......but SHhhhhhh

Oh, or http://people.ucsc.edu/~tbabb/programs/pokerodds/ SHhhhh again lmao

[pedigreechump6]

I think I might have worked out the meaning of masterplan's odds.

The program gives you percentage probabilities and you can choose from "deal to flop", "deal to turn" or "deal to showdown" and my understanding of it is that "deal to flop" actually tells you the probabilities of each hand being the best at this one stage, NOT the probability that it will go on to
win in the showndown.

So the pair of jacks has a higher chance of being the best hand after the flop than after the showdown which makes sense.