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poker and basic math

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  • poker and basic math

    Hello everyone,
    When I look at videos or listen poker classes I often hear something like

    "Pot sized bet needs to work 50% to break even"
    "This reraise preflop needs to work X% of the time"

    but it's not clear to me what that actually means and where those percentage come from..

    Can please somebody tell me more about it ??

    I will appreciate

    thank you


  • #2


    • #3
      lets make everything simple ,
      we are at river pot size is $90
      we have betting player we name B and calling playing we name C

      B bet $90 to steal the pot 90/ (90 + 90) = 50%
      so B only need to be correct more then 50% of the time he will be be profitable
      if C not defending 50% of the time B will be profitable

      C need to call $90 to win the pot $90 + B bet size of $90 so total $180 so 90/ (90 + 180)=33%
      so C need to be correct more then 33% of the time to make his call profitable

      if B decided to bet $30 to steal the pot 30/ (90+30) = 25%
      so B need to correct more then 25% of the time to be profitable
      if C is not defending 75% of the time B will be profitable

      C need to call $30 to win pot $90 + B bet size $30 = $120 so 30/ (30+120)= 20%
      so C need to be correct 20% of the time to be profitable


      • #4
        how often 75% of the pot needs to work guys as a pure bluff?

        can you please me tell me more about that?

        thank you


        • Paul Khoo
          Paul Khoo commented
          Editing a comment
          you are right and correct in some way to say that by betting 1/3 of the pot, the smaller size will have less risk, but when you bet small you will also increase the chances of opponent calling you. let me give you example you raise preflop , i call flop come A 7 2 rainbow, if you bet big 75% - 100% pot i might fold my hand 33, when you bet small ,i might still call down one street to see future action. lets say you have 89, do you want my 33 to call here? an another example if i have TJs , you bet 1/3pot also fold , so you are using less money to bluff away me that is better then you betting big to bluff me . but by betting big you increase the chances of my weak hand to fold, by betting small you increase the chances of opponent weak hand to call.

          to add on in certain board most player are not defending 75% of the time , and sometime you have a value hand you want player to defend more so you can get more value. lets say you have AK in A 7 2 board you want alot worst hand to call you , you want 33 to call you , you want KQ to call you , you want A4 to call you , you want TT to call you, by betting big some of this weak hand will fold to you.

          by betting big or small not only for bluff, but also for value, you want to control the range of card defending , the bigger you bet the range of card that you face will be tight and strong , the smaller you bet , most opponent range will be wide and weak, of course by checking you allow opponent range to be the widest, he can have any two card that call from preflop
          Last edited by Paul Khoo; 01-10-2019, 04:24 PM.

      • #5
        If the pot is $100, you are betting 75% of the amount in the pot, which is $75.

        To figure out how much a bluff needs to work: f = bet/(bet + pot); here it is f = $75/$175 = 43% of the time.


        • #6
          That's a good inclination you've had to look further into this. I think it's extremely useful to know and have spent a lot of time myself making sure to understand it and implement.

          I like this quote from Fitzgerald's Myth of Poker Talent:

          "The Bellagio didn't build those fountains not knowing the odds on every bet in their property. If we're going to be laying odds to another human being we're only playing ourselves if we don't know what we're offering."

          Attached Files


          • #7
            I try to give myself at least a 5% profit margin, that's why I added the +5% BE% on the end there. I also have it expanded to include when Hero is betting w/outs.


            • #8
              To figure pot odds, divide risk by (risk + reward). Pot is $100. Villain bets $50. His risk is 50. 50/(50+100)= 33%. For me to call, I will risk $50 to win $150, so my odds are 50/(50+150), or 25%.
              To determine if your call is profitable you need to compare it to your hand equity. Without including implied odds or future fold equity, my hand equity needs to be over 25% to be long term profitable. Equilab and Flopzilla are nice for this.
              A quick way to determine your hand equity heads up is to use the rule of 4 and 2. Count your outs.
              For every out, multiply by two, then by the number of cards left to come. For every out 9 and above, subtract the difference from 9.
              Say I have an open ended straight draw with a flush draw on the flop. Nine outs to the the flush and 8 outs to the straight, but two of them are duplicates. 15 outs.
              15 outs times 2, times 2 cards to come minus (15-9) = 54% equity. With a straight and a flush draw on the flop, I can call every time and be profitable, as I will win over half of the time, assuming I win every time I hit a hand.
              Last edited by MOUSE85; 01-11-2019, 04:56 AM.


              • #9
                This looks complicated, but its very simple once u wrap your head around it. I'll try and make it as simple as possible.

                You and I play a hand of poker. There is $100 in the pot. You want to bet and take the pot. You bet $100. That is 100%pot. this needs to work 50% of the time. Why?

                The first time this happens I reraise you and you fold. You lost $100. We play another hand and the same thing happens. Only this time I fold. You win the pot.

                So in total your bet worked 50% of the time. First time it didnt work, second time it did work. So we should be exactly break even.

                First time you invested $100 and lost it..
                Second time you invested $100 and won a $200 pot. (that is your $100 investment plus the $100 already in the pot)
                So in total you invested 2x $100 and you won $200. That is exactly break even.

                Now do this again, but we try a $50 dollar bet. This is a 50% bet and needs to work 33% of the time. Why?

                First time you invest $50 and lose.
                Second time you invest $50 and lose.
                Third time you invest $50 and win the $150 pot (your $50 investment plus the $100 already in the pot)
                So in total you invested 3x $50 and you won $150. That is exactly break even.

                So to get your break even point,how do you calculate that? Take your bet and divide that by (your bet plus what is already in the pot).

                In the first example: $100 (that is your bet) divided by $200 (that is your bet plus what is already in the pot). 100/200=0.5. That is 50% You need to win this pot 1 out of 2 times
                Second example: $50 divided by $150 50/150=0.333.... That is 33% You need to win this pot 1 out of 3 times

                In Alex Fitzgerald's video he says a 75% bet needs to wrok 43% of the time. Let's see if that is right for our $100 pot.
                $75 (our bet) divided by $75 + $100 (our bet plus what is already in the pot) = 75 divided by 175 = 0.428..... That is 43%! He is right!

                This will work for any pot and any bet. Try it on a calculator.
                Lets say pot is $5869. 75% bet is $4402. 4402/(4402+5869)=0.428.... =43%
                50% bet is $2935. {try it yourself} =33%
                100% bet is 5869 {try it yourself} =50%

                I hope this makes you get it. Good luck!
                Last edited by K2P2; 01-11-2019, 06:11 AM.


                • #10
                  Clear enough

                  Thank you to all


                  • #11
                    You are absolutely right. In poker, mathematics is of great importance and you should not underestimate probability theory and other mathematical techniques in order to win at poker. My brother told me all about it in detail and I was interested to know how it works in practice. I found some cool online casinos on mt-plus and started playing there using my own mathematical analysis strategy and soon I realized that it really works. I was just shocked and could not even imagine what kind of opportunities this opens up for making money from this. So math can help you very well with that.
                    Last edited by pudge26; 11-13-2020, 06:21 AM.