How to find percentages...

I always see on TV or read about this hand or that hand being a 2 - 1 favorite against another. Can someone tell me in as basic a way as possible HOW to figure that out? Please, I read all the time but I cant find it in any book Ive read. Thanks in advance.

Preflop or postflop?

http://www.pokerstove.com

http://www.pokerstove.com/

EDIT: I'm Too Slow

pokerstove is not helpful because it gives me the percentage. I want to learn how to figure out the percentage.

Originally Posted by guiltyjoe

pokerstove is not helpful because it gives me the percentage. I want to learn how to figure out the percentage.

???

The percentage tells you that..

AA v KK allin preflop is 80% - 20%
80/20 = 4
AA is a 4:1 favorite

AK v AQ allin preflop is 75% - 25%
75/25 = 3
AK is a 3:1 favorite

Originally Posted by guiltyjoe

pokerstove is not helpful because it gives me the percentage. I want to learn how to figure out the percentage.

The percentage is based on all the possible card combinations to follow and what pot equity each remaining player has should that combination fall. Run in its normal mode, PokerStove iterates through all possible card combinations, something that humans would have trouble with.

You can come close to the same numbers by computing the outs.

Consider that Player A has :As: :Ac:
and Player B has :Td:

and the board is:



Any of the 4 6's and any of the 4 Jacks would give Player B the winning hand. He is said to have 8 outs. In turn, we know 8 total cards, leaving 44 cards unknown. Thus he has an 8/44 chance of winning or 18%, while the AA has an 82%.

Edit: On TV, they also can take dead cards into account because they know some additional cards. Consider the above hand but the micro cameras caught a :Js: :Qd: hand that folded.

So, 1 of the Jacks is not available (leaving only 7 outs) and we know 10 cards instead of 8, leaving 42 cards unknown. So Player B would have a 7/42 chance of winning or 16.7%.

Originally Posted by martindcx1e

http://www.pokerstove.com/

EDIT: I'm Too Slow

You're not too slow, I'm just the fastest forum surfer alive.

Postflop, I calculate my percentage by working out my outs, (the cards I need to win), and multiplying the number of outs I've got by 4 after the flop, and 2 after the turn. Although this method serves as more of a rough estimation than a definite number. Preflop percentages, I don't know how they're done. I tend to make an informed guess, and I usually get it within 5%.

That is a great help. I have a follow up question though...

How do you figure out percentages PRE FLOP?

Again, thanks in advance.

Originally Posted by guiltyjoe

That is a great help. I have a follow up question though...

How do you figure out percentages PRE FLOP?

Again, thanks in advance.

You determine them exactly the same way; by looking at all the possible 5 card boards and each player's pot equity for each of those boards. And, again, for humans this is virtually impossible due to the number. If you knew your 2 hole cards and your opponent's two hole cards, then there would be 1,712,304 possible boards. You would weight those based on win/lose/tie to compute that percentage.

As each specific problem is essentially intractable with just a human brain at your disposal, here are some common guidelines:

Overpair vs Underpair: :As: :Ac: vs :Qs: :Qc:
80% vs 20%

Overpair vs Under non-pair: :As: :Ac: vs :Qs: :Jc:
85% vs 15%

Pair vs Highcard match non-pair :Ts: :Tc: vs :Td:
90% vs 10%

Pair vs Lowcard match non-pair: :Ts: :Tc: vs :Kh: :Td:
70% vs 30%

Pair vs Over/Under non-pair: :Ts: :Tc: vs :Qd:
70% vs 30%

Pair vs Over non-pair: :Ts: :Tc: vs :Qc: :Jd:
55% vs 45%

Over non-pair vs Under non-pair: :Qs: vs
65% vs 35%

Interleaved non-pairs: :Qs: vs :Tc:
65% vs 35%

Non-pair vs interstitial non-pair: :Qs: vs :Jc:
60% vs 40%

Non-pair vs non-pair matching highcard: :Ac: :Td: vs :As:
70% vs 30%

Non-pair vs non-pair matching lowcard: :Ac: vs :Kh:
70% vs 30%

In each of these cases, if a hand is suited it gains a few percent vs an unsuited hand. Also, if unpaired hands are close enough to be in the same straight then they gain a few percent. And finally, due to things like straights and counterfeiting, some of the numbers can change quite a bit if the cards are bumped up against the top or bottom of the ranks.

You're a great help. Thanks very much.