calculating pot odds/outs question

[doraemon145]

NOTE: 2 people has taught me how to calculate pot odds and outs in 2 different ways. which is right?

METHOD 1
lets say i have 15 outs after flop. 15/47=32%
one other person is left, and he bets $4 making it $14.
this makes it 4:14, which equals 1:3.5, which equals 1/4.5, which is 22%
32% to 22%. I will call.

METHOD 2
lets say i have 15 outs after flop. 15:47, which is equal to 1:3.133, which is 1/4.133, equals around 24%
one other person is left, and he bets $4 making it $14.
this makes it 4:14, which equals 1:3.5, which equals 1/4.5, which is 22%
24% to 22%. I will call

WHY IS IT DIFFERENT PERCENTAGES IF ITS SUPPOSED TO BE THE SAME?

[kizzik]

The first method that you outline is correct.

31.91% = 68.09% to 31.91% = 2.1333 to 1

The methods that I know of to calculate the odds of making one's hand with the next card:

1. Divide the number of unknown cards by the number of outs that you have

2. Subtract one from the result

e.g. For your example...

47 / 15 = 3.1333
3.1333 - 1 = 2.1333

The odds of making your hand are 2.1333 to 1.

Alternatively:

1. Subtract the number of outs that you have from the number of unknown cards

2. Divide the result by the number of outs that you have

e.g. For your example...

47 - 15 = 32
32 / 15 = 2.1333

The odds of making your hand are 2.1333 to 1.

Either way works, it's just up to your personal preference.

Your calculation for working out pot odds is correct.

A $14 pot with a $4 call to you gives pot odds of 3.5 to 1.

[doraemon145]

The first method that you outline is correct.

31.91% = 68.09% to 31.91% = 2.1333 to 1

i'm sorry, how did you get 68.09% and whatnot? I'm not understanding this

[kizzik]

To calculate the percentage chance of making your hand on the next card:

1. Divide the number of outs to make your hand by the number of unknown cards

15 / 47 = 0.3191 = 31.91% (approximately 32%)

To convert percentage chance to odds:

1. Subtract the percentage chance to make your hand from 100

2. Divide the result by the percentage chance to make your hand

100 - 31.91 = 68.09

68.09 / 31.91 = 2.1333

Or,

1. Divide 100 by the percentage chance to make your hand

2. Subtract 1 from the result

100 / 31.91 = 3.1333

3.1333 - 1 = 2.1333

[kizzik]

I generally find it's easier to work in odds all of the time rather than percentage chances.

Whichever way you like to work, it is probably easier to have a little table of odds or percentages printed out for all of the common numbers of outs. Anything not on your table can be approximated by looking at where the number of outs fits into the table.

Most poker books and tutorial websites would have this sort of table somewhere in them.

[RiverMonkey]

First of all, make sure you understand the distinction between odds-against, and probability. Poker players (and gamblers in general) typically work with odds-against rather than probabilities because it is the most direct way to compare whether or not you are entering into a favourable bet or not. If the pay off for a bet is better than the odds against winning then its a good bet whether you end up winning on that specific instance or not.

See below for details on Odds-against versus probability. Then, read the following post and hopefully it will clarify things for you in terms of quick at-the-table pot-odds calculation tricks.

http://www.flopturnriver.com/phpBB2/...pic.php?t=7635

Odds against versus Probability
------------------------------------
The odds against rolling a 6 on a 6-sided dice is 5:1. That is, over enough rolls of the dice, you'll expect to see a 6 come up once for every 5 times that it comes up another number, so the odds against seeing a 6 are 5-to-1 against. Note that the two numbers in the odds against ratio when added up always equals the total number of possibilities (6 in this example).

Probability focuses on looking at the likelihood of an event occuring, with zero being 'not going to happen' and one being 'absolutely will happen'. So, with the dice example, the probability of rolling a 6 is 1/6 or 0.166666. You can convert this to a percentage probability (16.6666%) which is really just re-nomalizing to a scale of 0 to 100 rather than 0 to 1. To convert this to odds-against, just realize that you are essentially looking at the odds for something happening when dealing with probabilities whereas in dealing with odds-against you are looking at the odds of something NOT happening. If for example, the probability of getting hit by a car on the way home was 25% (let's hope this is a high estimate ) then the natural question to ask is what are the odds against getting hit by a car? Well, 25% as a probability is 0.25, or 1 out of 4 times. So, the odds against getting hit by a car would be (4-1):1 against or 3:1 against. For every 4 trips home on average you make it home safe 3 times, and get splattered all over the road the other 1 time.

You should work through a few poker specific examples so that you make sure you understand how to covert from probability to odds-against and vice-versa. This is really just to help you understand the concepts and how they apply, but after a while you'll find that when playing poker you just have to know the size of the pot or estimate the eventual size of the pot and compare that to memorized draw odds based on number of outs.