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Maths help - Sat Apr 26, 2014, 02:20 PM
(#1)
mike2198's Avatar
Since: Jan 2013
Posts: 1,485
Im having trouble with some calculations can someone tell me what im doing wrong please.

If i have to call a pot sized bet on the river im getting 2 to 1 so i need to be good 33% of the time.

So i f i were to do that in the calculator and the pot was $50 then the calc would look something like this 50+50+50/50 (pot+bet+my call divided by my call)

Which equals 3 which is confusing me because when i do it in my head i think 2 to 1.

That seems pretty simple but not if we change the bet size it gets complicated.

So if the pot is $50 and villain bets $30 i see the pot is $80 and in my head i look at that and see 2.3:1 pot odds and if 2:1 is 33% 2.3 must be more like 29-30%

But if i do this in the calculator i get confused because when you press equal you dont get 2.3, so i would put 50+30+30/30 =3.6 and then if i press 1/x i get 0.27.

So im assuming that calc is right but its all very confusing because if im at the table and see im getting 3 to 1 i see i need to be good 25% but then the calculator has 3.6 at 27% and that looks closer to 4 to 1 to me.

All this came up from a vid i was just watching where the guy said we need around 40% off the top of his head when hero 3b AJ and a 50bb stack shipped all in.

The hand went like this UTG opens 7 hero makes it 22 and BB ships 98 so pot is 128 with the SB and we need to call 76.

So again if i was at the table now i see we need to call 76 into 128 which i have no idea how to do that in my head but i know its around 1.7ish so i need more than 33% so i would be going with some where around 40%.


But if i pull out my handy calculator i see 2.6 or 37%, so im like why is the calc doing 2.6 when i see 1.7 or 2.3 i get 3.6 from the calculator, this is all very confusing.

So does it look like im doing these pot odds in my head at the table right or am i wrong and has anyone got a easier/ faster way of doing things at the table?

Last edited by mike2198; Sat Apr 26, 2014 at 02:23 PM..
 
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Sat Apr 26, 2014, 03:04 PM
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Since: Nov 2012
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i try not to think of it in fractions, i think of it in percentages

if i have 5 outs on the flop and the pot is 500 with a bet 100 to me.
My outs give me 2% each per street and in this case I need to judge 1 street, so thats 10%
For the pot odds to be good, the bet to call must be 10% of the pot, in this case it is 20% of the pot so the only way I could call is if i had 10 outs or if the bet was 50

I hate the x:y version of the principle because it confuses me when i am figuring my outs which i do in percentages.

I hope this helps

Other than that, use a calculator each time until you get used to it
 
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Sat Apr 26, 2014, 03:06 PM
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Originally Posted by mike2198 View Post
But if i do this in the calculator i get confused because when you press equal you dont get 2.3, so i would put 50+30+30/30 =3.6 and then if i press 1/x i get 0.27.
27% is correct here. I have to put $30 into a pot that will be $110, so my pot equity is 30/110 or 27.3%

For the pot sized bet, I need to put 50 into a pot that will be 150, so I will have 33% pot equity.

I always do them this way, as it's easier for me to figure out this way. it's... $ put into pot/total pot (and the total pot has to include my contribution)

John (JWK24)


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Sat Apr 26, 2014, 03:30 PM
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mike2198's Avatar
Since: Jan 2013
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Quote:
Originally Posted by JWK24 View Post
27% is correct here. I have to put $30 into a pot that will be $110, so my pot equity is 30/110 or 27.3%

For the pot sized bet, I need to put 50 into a pot that will be 150, so I will have 33% pot equity.

I always do them this way, as it's easier for me to figure out this way. it's... $ put into pot/total pot (and the total pot has to include my contribution)

John (JWK24)
How do you do that in your head though i can get 30 into 110 bit but then to divide 110 by 30 in my head isnt going to happen. Is there a way to make the numbers easier like if i wanted to work out what 90x70 was i would make it 9x7 and add a 0 but i cant think of a way to simplify that number.

Im so bad at math i can seem to do stuff in my head some where near but if i use a calculator or i write out a sum on paper im lost. Ive never been good at percentages and fractions mainly because i wasnt interested. Im decent at multiplication and that so i see no reason why i shouldn't be able to get my head round this but i cant work out away to simplify the math myself.

My attempt at it would be 3 into 12 is 4= 25% but the pots 110 so we need to add a few more % on. Or maybe more accurately would be 3 into 9 3=3 33% so i need some where between 33 and 25%. That still seems abit to slow though when i look at it my way i can do it in a second but then i find it hard to put it in a percent unless its easy like 25 33 66 20 and so on.
 
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Sat Apr 26, 2014, 04:02 PM
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baud2death's Avatar
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Dont overthink it

just round numbers

So if you have 4 outs, 2% per out, thats 8% - just call that 10% (trust me, it wont matter)

Now, if the bet to you is GREATER than 10% of the pot, you fold. If the bet is LESS than 10% of the pot you call.

Lets say you have the classic flush outs, 2 in your hand, 13 in the deck so 11 possible, a flush draw on the flop takes 2, that makes 9 possible.

9 outs (call them 10) so a decision from FLOP>TURN is 2% per out, 20%

If the pot is 1000 chips and your opponent bets GREATER than 20% of the pot you fold and LESS than 20% you call. 20% of 1000 is 200, so a 0-190 bet would be a call and 200+ would be a fold.


Sadly, if you can't do the maths even when rounding then i can't help and recommend you google odds calculators online
 
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Sat Apr 26, 2014, 04:11 PM
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Originally Posted by mike2198 View Post
How do you do that in your head
I simplify them down as much as possible and have many of the basic numbers memorized (any of the ones up thru x/11) If it's something higher than 11, then I just estimate it as to the closest thing that I do have memorized... then go thru them afterwards with a calculator.

For me, trying to do them the other way confuses me... and I'm one that set the curve in differential equations in college (the hardest math class an engineer has to take).

John (JWK24)


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Sat Apr 26, 2014, 04:20 PM
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mike2198's Avatar
Since: Jan 2013
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Quote:
Originally Posted by JWK24 View Post
I simplify them down as much as possible and have many of the basic numbers memorized (any of the ones up thru x/11) If it's something higher than 11, then I just estimate it as to the closest thing that I do have memorized... then go thru them afterwards with a calculator.

For me, trying to do them the other way confuses me... and I'm one that set the curve in differential equations in college (the hardest math class an engineer has to take).

John (JWK24)
Whats x/11?
 
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Sat Apr 26, 2014, 04:27 PM
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any number divided by 11

1/11 = about 9%
2/11 = about 18%

etc.


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Sat Apr 26, 2014, 04:37 PM
(#9)
mike2198's Avatar
Since: Jan 2013
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Quote:
Originally Posted by baud2death View Post
Dont overthink it

just round numbers

So if you have 4 outs, 2% per out, thats 8% - just call that 10% (trust me, it wont matter)

Now, if the bet to you is GREATER than 10% of the pot, you fold. If the bet is LESS than 10% of the pot you call.

Lets say you have the classic flush outs, 2 in your hand, 13 in the deck so 11 possible, a flush draw on the flop takes 2, that makes 9 possible.

9 outs (call them 10) so a decision from FLOP>TURN is 2% per out, 20%

If the pot is 1000 chips and your opponent bets GREATER than 20% of the pot you fold and LESS than 20% you call. 20% of 1000 is 200, so a 0-190 bet would be a call and 200+ would be a fold.


Sadly, if you can't do the maths even when rounding then i can't help and recommend you google odds calculators online
Yh i can do all that i want to get a more accurate number on the river for calling a river bet. So if i had to call a pot size river bet and i thought i would win 1/3 of the time with what ever hand i have i should call, or if i 3b and a shorty ships i need to know what range he is shipping and if i have enough equity to call with my hand vs his range which is pretty complicated when the numbers dont add upto what you memorized.

Like take that AJ hand i posted further up the guy teaching knew he needed 40% equity to call and then he knew that vs this guys range he had a fold. Where i would just fold because i think im crushed anyway.

Ive tried odds calculators but i dont do it like that in my head like with the calculations i did with the calculator i added my call into the calculation but when i do it at the table i dont do it like that, i see the pot size and how much i have to call so pot is 100 i have to call 50, 50 goes into 100 twice so i get 2 to 1 and then i do that for what ever the bet size and then see what the % is but i cant work out like the % for in between like 33 and 50% and the calculator dont help me because i dont do it that way it seems John does it like that, im just looking for an easier way to do it.

Not that it will be any use to me to calling the river because i would still need to know what villain is potting the river with.
 
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Sat Apr 26, 2014, 04:47 PM
(#10)
ArtySmokesPS's Avatar
Since: Oct 2011
Posts: 7,324
Just remember the following numbers:

On the left is the percentage of the pot that villain bets. On the right is how often you need to be right to break even.

Betsize (% of pot) - Equity needed to call
100.0% - 33.33%
75.0% - 30.00%
60.0% - 27.27%
50.0% - 25.00%
40.0% - 22.22%


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Sat Apr 26, 2014, 06:10 PM
(#11)
mike2198's Avatar
Since: Jan 2013
Posts: 1,485
Quote:
Originally Posted by ArtySmokesPS View Post
Just remember the following numbers:

On the left is the percentage of the pot that villain bets. On the right is how often you need to be right to break even.

Betsize (% of pot) - Equity needed to call
100.0% - 33.33%
75.0% - 30.00%
60.0% - 27.27%
50.0% - 25.00%
40.0% - 22.22%
How do i know there bet size is 40% though if the pot was 35 instead of 100.

I think i worked out a way i understand

2 to 1 = 33%
3 to 1 = 25%
4 to 1 = 20%
5 to 1 = 17%

and the hard one im not sure i got right but it took me ages to work it out is 1.5 to 1 = 40%

To get 1.5 to 1 say pot is 132 and i have to call 88, i would take 88 and half it = 44 then add them together = 132 = 40% does that make sense have i got that right?

I hope so because i can do that easily and if i cant half it like that i know i need between 2.1 and 1.5 so i would need between 33% and 40% so 1.7 would be like 37%
 
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Sat Apr 26, 2014, 06:35 PM
(#12)
ArtySmokesPS's Avatar
Since: Oct 2011
Posts: 7,324
Quote:
Originally Posted by mike2198 View Post
How do i know there bet size is 40% though if the pot was 35 instead of 100.
Well villains often use standard bet-sizes with the action buttons. If they bet less than half pot, it's usually gonna be around 33-40% of pot, and your equity doesn't have to change much to make profitable calls against underbets like that.

Quote:
Originally Posted by mike2198 View Post
the hard one im not sure i got right but it took me ages to work it out is 1.5 to 1 = 40%

To get 1.5 to 1 say pot is 132 and i have to call 88, i would take 88 and half it = 44 then add them together = 132 = 40% does that make sense have i got that right?

I hope so because i can do that easily and if i cant half it like that i know i need between 2.1 and 1.5 so i would need between 33% and 40% so 1.7 would be like 37%
Yes, 1.5:1 is the same as 3:2 or 30:20 or 60:40, meaning you need 40% equity, but it's not very common for villain to bet so much on the river that you need to be right that often.
If you had to call 88 to win 132, then villain must have bet two times pot. (88 into a 44).


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Sat Apr 26, 2014, 07:02 PM
(#13)
mike2198's Avatar
Since: Jan 2013
Posts: 1,485
Cool im just thinking for like that spot with the AJ hand i posted where the BB shipped pre, glad that worked out right anyway i find it easier doing it like that. Cheers for your help everyone i think i can do this myself now.
 

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