Quick question % versus ratio

Z

zucker

Rising Star
Hi there,

I have asked a couple of people about this, but somehow I just cannot understand it. Maybe you can help!

OK, so:

Pot is 100. It's 50 to call.

U.S. style:

100/50=2-1=33% (1/3) equity needed. = I need to win one game out of three to break even.

Simulation

1. Game = -50

2. Game = -50

3. Game =+100 (What happens with my 50 Call here)?

EU style:

50/150 (total pot including my call)=33%

I need 33% eq to play this.

1. Game = -50

2. Game = -50

3. Game = -50

4. Game = +50 + 100

From my understanding that's 3-1 not 2-1, meaning 25% instead of 33%. Why are my results different? Which method should I use? I just want to compare my pot odds with my equity. But I feel like factoring in the call or not gives me different results. So, I am not making the right bets/calls in the long run.
 
Last edited:
Nafor

Nafor

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I dive in again...

Pot is 100. It's 50 to call.

U.S. style:

100/50=2-1=33% (1/3) equity needed. = I need to win one game out of three to break even.

Simulation

1. Game = -50

2. Game = -50

3. Game =+100 (What happens with my 50 Call here)?

This is correct. On third you win the pot and get your bet back, so three games combined - you win nothing, you lose nothing.


EU style:

50/150 (total pot including my call)=33%

How are you arriving to this number? Are you saying bet/bet+pot? This leads to wrong conclusion. Your above version is the right one.
 
Z

zucker

Rising Star
Nafor, thanks for your advice again.

These are the resources I am referring to:

https://www.masterclass.com/articles/learn-poker-what-are-pot-odds#pot-odds-and-expected-value

https://poker.stackexchange.com/questions/9161/confused-about-pot-odds

https://www.cardschat.com/forum/general-poker-13/correctly-calculating-pot-odds-does-your-96123/

I guess what I am confused about is

a) if we say pot is 100, call is 50. So, it's 2-1 because 100/50. To get to the percentage, we either divide 50/150 or 1/(2+1)= 33%

1. -50
2. -50
3. ? What happens with my call (I will win a 100. That I know.)

--

If we calculate %, we always divide the call by the total pot. 50/150=33% in this case. So let's have a look, when we break even:

1. -50
2. -50
3. -50
4. +150 (what happens with my call)?

And isn't that 3-1?

I think the main question is: do we express a win/loss probability by the ratio or the call - profit relationship (in that case what is profit, do I always subtract my call for that?).

Thanks again, Z
 
3

300HPGOD

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This question came up in another thread so I will paste my response from that thread into this one. Method 1 for the below is the US way as you call it and method 2 is the EU way as you call it. You are confusing yourself as the outcome of the hand. Its the same outcome either way for hand 3 which is we bet 50 and get 150 pushed back to us when we win so profit is 150-50=100. First two hands lose -50 each so -50-50+100=0. This is the same for either method you use. Difference is in the EU method you dont have to add 1 to get the how many times do I need to win to break even. Hopefully the below helps you. It seems many people are getting confused on the two methods.

You can do it either way as long as you understand the method you are using. I will call them method 1 and method 2. Method 1 is not adding your bet in and method 2 will be adding your bet in.

Method 1: Example is 1200 pot and we face 400 to call. Our pot odds are 1200/400 which is 3 so we are getting 3 to 1 on our money. For us to break even we have to win 1 out of 3+1 times meaning we have to win 1 out of 4 times. It is 1 out of 4 and not 1 out of 3 because if we call and we win then the pot moved our way is 1600 (1200+400 (our call)) so 1 out of 4 times is breaking even. If that example is confusing think of a coin flip where you betting 1 and win 2 (1 dollar you bet and win an additional 1 dollar) if you pick heads or tails correctly (even money bet). Even money is considered 1/1 but to break even on this bet we can lose one time and win the next time so we need to win 1 out of 2 times and not 1 out 1 time. When using method one you need to understand the idea that whatever the pot odds are you have to add 1 to the 1 out of how many times I need to win to break even.

Method 2: In this method you add your bet into the pot so in the previous example you would be calling 400 into the 1200 pot so our pot odds are 400 to win 1600 (including the bet with this method) so we are 4 to 1. Here since you already added your calling bet into the calculation you do not need to add the 1 to get the number of times you need to win to break even. It would just be whatever the calculation comes out to so in this case its a simple 1600/400 or 4 to 1.
 
NWPatriot

NWPatriot

Rock Star
pot odds is a pet peeve of mine. Odds are odds and equity is %. The poker community uses a % value for pot odds over and over again, and it just adds confusion. I have started clarifying this as "pot odds" and "pot odds equity" to be specific and clear at all times.

Pot =100, bet =50, call = 50.

Pot odds are 3:1. We call 50 to win 150. 150/50 is 3:1. (pot + bet)/call as odds.

Pot odds equity is the equity we need to breakeven on the call (ignoring any previous investment). The best formula for this is: call / (pot + bet +call) or 50 / (50 +50 +100) = .25.

We can get to the same place by taking the odds, and then converting them to %, but this saves one step. This one formula eliminates the need to convert odds (xx:1) to %. If we win 25% of the time, or 1 in 4 hands, we will win one and lose 3 for a 3:1 ratio. It all works out and tells us what we need to quickly.

Pot odds equity = call / (pot + bet +call)

Good luck and God bless
 
Nafor

Nafor

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I think the main question is: do we express a win/loss probability by the ratio or the call - profit relationship (in that case what is profit, do I always subtract my call for that?).

See how "our own" poker pro, Collin Moshman calculates this in this example starting from 6:36.

https://www.cardschat.com/become-a-winning-poker-player/day-5/

He divides the pot (1350), which does not yet include hero's call (400), with hero's call.

1350/400 = 3.375 and it is rounded to 3.4

Turning that into percentages is 100/(3.4+1) or like in your example (call/(call+pot)) so 400/1750, and we get 23%.


If you calculate like Collin...

1) lose 50
2) lose 50
3) win 100
So you break even.

But if you play four games and expect to win only one in four - you spend 200 to play those games and receive only 150 in return - that is not breaking even.

Remember how the winnings are calculated here in parts 4 and 5.
https://www.cardschat.com/odds-for-dummies.php

The equity is 4:1 but pot odds are 10:1 and the amount to call is 10$.

The pot (without your call) is 100. Four times you lose 10, and on the fifth time your winnings are 100-40 = 60.
 
frnandoh

frnandoh

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I think it is just a math perpective matter:

Pot=100
Call= 50

Fraction
50/150 >>> 1/3

Ratio
50 : 100 >>> 1 : 2

Both notation are equal and have the same value in percentage.

1/3 = 1 : 2 = 33%

I hope that helps. I love poker math, but my english is horrorrible, so if I got, that is what you was talking about.
 
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