LOST- Probabilities/Equity/Pot Odds: Ratios/Percentages

Z

zucker

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Hi there,

If this has been raised before, I am very happy to delete it. Sorry to have bothered you. I am very confused at this point. If this reads like gibberish, it does so because it is.

So, I am a total rook, currently reading the Harrington on Hold em series, playing low stakes MTTs and Sit and Gos. Since he is using ratios, I would also like to compare equity/probability and pot odds as ratios. I understand odds to draw as the likelihood to make my hand, pot odds as the money I could win for the money I pay for a call, and equity as my likelihood to win the hand in a showdown (ignoring fold equity for now). I understand that if I want to bet or call I always need higher pot odds than drawing probabilities or equity. Since I calculate pot odds as ratios, I need equity and drawing probability in the ratio format as well.

My questions:

What is the difference between drawing probability and equity?

How do I calculate equity? For instance, high cards are a 3-1 underdog v low-pair post-flop and 13-10 pre-flop (says Harrington in vol 2). Do I just need to know that?

How do I calculate drawing probability as a ratio with the 2/4 rule?

Where do I find good memorizing equity charts in ratio sizes for the most common hand v hand scenarios pre-flop and post-flop? What should I commit to memory? My equity against a random hand? My equity against the hand I think that has me beat? The equity against common scenarios?

How do I transform an odds against ratio (number of failures per success) to a odds for ratio (numbers of successes)? Which type should I use in general? Harrington uses numbers of failure per successes for drawing probabilities and numbers of successes per failure for equity. An example: Like Harrington says top pair has 82% eq v lower pair or 4.5-1 (numbers of successes I presume). What if I hold the low pair?

How do I transform ratios to percentages and vice versa? I read something re pot odds about this and it makes sense, but eq/probabilities confuse me here.

Thanks, Z
 
Z

zucker

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So, I think my understanding of this matter has improved a bit.

What would you recommend a beginner for

- calculating equity (at the table - so no software)

- which scenarios should I have committed to memory (what's a good site to learn them)?
 
Nafor

Nafor

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Welcome to CardsChat zucker,

I try to reply at least to some of your question. Let's take one step at a time...

I understand odds to draw as the likelihood to make my hand
TRUE
pot odds as the money I could win for the money I pay for a call
It would probably be easier if you thought pot odds simply as number that you are comparing to equity.
and equity as my likelihood to win the hand in a showdown.
Not exactly. Your equity is not fixed. It changes when the hand evolves.
I understand that if I want to bet or call I always need higher pot odds than drawing probabilities or equity.
I'm not sure how you have understood this? Your probability to make your hand needs to be higher than your risk of loosing money in similar situations in the long run. That is the basic way. So for example, if your probability to make your hand is 4:1 but your pot odds are 2:1 you don't make the call.
What is the difference between drawing probability and equity?
They are indicators that you compare against each other to make good decisions. There's really nothing more to it.
How do I calculate equity? For instance, high cards are a 3-1 underdog v low-pair post-flop and 13-10 pre-flop (says Harrington in vol 2). Do I just need to know that?
Read this.
How do I calculate drawing probability as a ratio with the 2/4 rule?
30 seconds or less in an online game is a tough spot to run calculations in your head. I suggest that you calculate the percetages and learn the equal ratios by heart so they will become as second nature to you.
Where do I find good memorizing equity charts in ratio sizes for the most common hand v hand scenarios pre-flop and post-flop? What should I commit to memory? My equity against a random hand? My equity against the hand I think that has me beat? The equity against common scenarios?
I suggest that you make one for yourself. You can start with common scenarios presented in the above link. Learning by doing is a good way to learn.
How do I transform an odds against ratio (number of failures per success) to a odds for ratio (numbers of successes)? Which type should I use in general? Harrington uses numbers of failure per successes for drawing probabilities and numbers of successes per failure for equity. An example: Like Harrington says top pair has 82% eq v lower pair or 4.5-1 (numbers of successes I presume). What if I hold the low pair?
I'm not sure what you are asking here?
How do I transform ratios to percentages and vice versa? I read something re pot odds about this and it makes sense, but eq/probabilities confuse me here.
This is basic math. You can see examples for both ways in here.


It is good that you are reading the Harrington but it seems that many of the basics are still lost. Why not take a different angle on this? CardsChats own free poker course is great for your skill level and you can do it at your own pace, and don't forget to read the pdf as well.
https://www.cardschat.com/become-a-winning-poker-player/
 
Z

zucker

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Nafor, thanks so much! These are great resources, I will certainly check them out. Thanks for responding so patiently and helpfully to my questions.
 
Z

zucker

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Hi, a follow-up question on ratio/percentage conversion:

I have tried to convert percentages to a ratio using the resource you have recommended (https://www.math-only-math.com/percentage-into-ratio.html).

I am using the example of a flush draw (https://www.cardschat.com/odds-for-dummies.php). On the flop, my probs of hitting my draw on the turn are 20% or 4:1.

OK, so. Let's divide 20% by a 100. That's 20/100. Reduce it to the simplest form. That's 2/10. Now, write it as a ratio. That's 2:10 or 1:5.

Where's my mistake? I am aware of the pot odds conversion for a ratio into a percentage( m:n->m+n->divide n by m+n). Do I need a special method for drawing probabilities? Thanks again!
 
Nafor

Nafor

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I should have explained this in more detail so I try to do it now.

Let's continue with the flush example:

20% is one fifth of a 100% when turned into fraction so the calculation is accurate. You just need to think of it a little differently when you change that into odds.

The example says: "you are 4 times more likely to lose this pot than you are to win it." So you have a one fifth of a chance to win it, and four fifths of a chance to loose it.

Are you still with me?

The fraction displays the result as 20% out of 100%,

but the odds way displays it differently

80% on the left / and 20% on the right.

Let me give you a more simple way to calculate this. This how to turn odds in ratio into percentages (the 4:1 example):

add 4+1
divide 1 with the result of the previous addition, so 1 divided by 5 is 0.20

Now multiply that result with 100.
0.20 times 100 = 20 percent.

So the whole calculation looks like this:

(1 / (4+1) ) x 100 = 20%
 
Z

zucker

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Thanks, again!
OK, and if we start from 20% to make the flush this is how I get to the 4:1 ratio (https://sciencing.com/convert-percent-odds-ratio-8685477.html)

20/100
1/0.2
5-1
Ratio = 4:1

Should I always use the style odds against making it (4:1) or the one for making it (1:4)? Same for percentages: should I speak of 20% of making it or 80% of not making it?

For pot odds I use this style of conversion (from https://en.wikipedia.org/wiki/Pot_odds)

Pot = 30
Call = 10
3:1
3+1=4
1/4=25%
Now I need at least 25% eq to call.
 
Nafor

Nafor

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Should I always use the style odds against making it (4:1) or the one for making it (1:4)? Same for percentages: should I speak of 20% of making it or 80% of not making it?

When people speak about equity/outs they refer to the odds of making it. So I would say 20% change of making it, and not the other way around.

Here's another calculator to make it simple. Just place the percentages in the 'implied probability' box and it gives you the ratio.
https://mybettingsites.co.uk/bet-calculator/odds-converter/

Edit. your numbers look accurate.
 
Last edited:
Evan Jarvis

Evan Jarvis

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Hi there,

If this has been raised before, I am very happy to delete it. Sorry to have bothered you. I am very confused at this point. If this reads like gibberish, it does so because it is.

So, I am a total rook, currently reading the Harrington on Hold em series, playing low stakes MTTs and Sit and Gos. Since he is using ratios, I would also like to compare equity/probability and pot odds as ratios. I understand odds to draw as the likelihood to make my hand, pot odds as the money I could win for the money I pay for a call, and equity as my likelihood to win the hand in a showdown (ignoring fold equity for now). I understand that if I want to bet or call I always need higher pot odds than drawing probabilities or equity. Since I calculate pot odds as ratios, I need equity and drawing probability in the ratio format as well.

My questions:

What is the difference between drawing probability and equity?

How do I calculate equity? For instance, high cards are a 3-1 underdog v low-pair post-flop and 13-10 pre-flop (says Harrington in vol 2). Do I just need to know that?

How do I calculate drawing probability as a ratio with the 2/4 rule?

Where do I find good memorizing equity charts in ratio sizes for the most common hand v hand scenarios pre-flop and post-flop? What should I commit to memory? My equity against a random hand? My equity against the hand I think that has me beat? The equity against common scenarios?

How do I transform an odds against ratio (number of failures per success) to a odds for ratio (numbers of successes)? Which type should I use in general? Harrington uses numbers of failure per successes for drawing probabilities and numbers of successes per failure for equity. An example: Like Harrington says top pair has 82% eq v lower pair or 4.5-1 (numbers of successes I presume). What if I hold the low pair?

How do I transform ratios to percentages and vice versa? I read something re pot odds about this and it makes sense, but eq/probabilities confuse me here.

Thanks, Z

Hey Z

Start around the 11 minute mark for the key betting related stuff

It's worth the full watch if you want the strongest foundation possible.

And then then followup video which will greatly help with preflop stuff is

[ame="http://youtube.com/watch?v=xUVQGobSCQY"]How To Play Poker Like A Pro ? The ULTIMATE poker strategy Preflop CHECKLIST (poker tips) ? - YouTube[/ame]

Hope that helps!
Cheers
 
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