Odds for Hold Em Flop Bet similar to Flop Roulette
wanted to bet $20 on every flop til one of us cried "UNCLE"!!
His bet was that a 2-4 or a J would come on the flop! THATS IT!
I didn't accept because I learned long ago not to take another mans bet.
I tried to do the math on this to see who had the best of it but couldnt do it.
I'm pretty certain that he has the best of this bet. But how much of an edge
does he have? Can someone show me the math on this?
I would also be interested to hear if anyone has any similar bets like this that
I might could try to pick up a few extra bucks on while playing poker.
Thank you for any help that anyone can give me.
Quote: FatBabyKateTonight at our holdem game one of the players offered me this bet.... He
wanted to bet $20 on every flop til one of us cried "UNCLE"!!
His bet was that a 2-4 or a J would come on the flop! THATS IT!
I didn't accept because I learned long ago not to take another mans bet.
I tried to do the math on this to see who had the best of it but couldnt do it.
I'm pretty certain that he has the best of this bet. But how much of an edge
does he have? Can someone show me the math on this?
I would also be interested to hear if anyone has any similar bets like this that
I might could try to pick up a few extra bucks on while playing poker.
Thank you for any help that anyone can give me.
I'll take a stab at this. But the math guys can please check it.
Without regard to people's 2card hands, since there's no way of knowing what anybody holds any given hand, but they are dealt before the flop:
2's, 4's, and J's are 12 out of 52 cards. A bit confused about how you wrote 2-4; could mean 2 through 4, 2,4 or requiring both a 2 and a 4 OR a J.
Assuming you meant individually...
12/52 = .230769, or 23% of the time.
12/51 assuming you miss = .235294
12/50 assuming you miss = .24
so you have to add those together, since he gets 3 chances to hit.
.706063, or 70.61% of the time he will win.
Total sucker's bet IMO.
(FWIW, adding isn't the right operation there.)
Quote: MathExtremistI read it as "the flop will have at least one of 2, 3, 4, J; I'll bet you even money that I'm right." So in order to win, the other player has to see all 3 flop cards from 5, 6, 7, 8, 9, T, Q, K, A. 9 ranks, 36 cards, 36c3 = 7140. Total number of flops is 52c3 = 22100. 7140/22100 = 32.3% chance to win, 67.7% to lose. Total sucker bet.
(FWIW, adding isn't the right operation there.)
Thanks, ME. Always learning, here.
There are a couple ways to fix this.Quote: beachbumbabs12/52 = .230769, or 23% of the time.
12/51 assuming you miss = .235294
12/50 assuming you miss = .24
so you have to add those together, since he gets 3 chances to hit.
a) Instead of adding the probabilities of hitting given that you missed the previous card, you can add the probabilities of missing and then hitting. You don't know yet if the first card missed, so you don't get to assume it beforehand. It has a probability which must be factored in.
12/52 + (40/52)(12/51) + (40/52)(39/51)(11/50) = correct answer (for the problem you answered)
b) Add 12/52 three times, then use inclusion-exclusion since that overcounts the ways two or three of the cards can hit. Draw 3 overlapping circles. One represents P(J hits), another P(2 hits) and the third P(4 hits). When you add all 3 circles, how many times have you counted each of the regions where 2 circles intersect? So then subtract those intersections as needed to make them only counted once. But once that step is done, how many times is the triple-intersection counted?
Quote: FatBabyKateTonight at our holdem game one of the players offered me this bet.... He
wanted to bet $20 on every flop til one of us cried "UNCLE"!!
His bet was that a 2-4 or a J would come on the flop! THATS IT!
I didn't accept because I learned long ago not to take another mans bet.
I tried to do the math on this to see who had the best of it but couldnt do it.
I'm pretty certain that he has the best of this bet. But how much of an edge
does he have? Can someone show me the math on this?
In a case like this, it's easier to figure out the probability that none of those cards would come up on the flop, then subtract the result from 1.
There are C(52,3) cards in a flop; there are C(36,3) different flops that do not contain any of those cards.
The probability of one of these flops showing up is C(36,3) / C(52,3) = ((36 x 35 x 34) / 6) / ((52 x 51 x 50) / 6) = 99/455.
The probability that a flop has at least one of the four cards is 1 - 99/455 = 356/455, or about 78% of the time.
Even if it is limited to a 2-4 showing up, that is 1 - C(40,3) / C(52,3) = 47/85, or about 55.3% of the time.
Quote: ThatDonGuyThere are C(52,3) cards in a flop; there are C(36,3) different flops that do not contain any of those cards.
The probability of one of these flops showing up is C(36,3) / C(52,3) = ((36 x 35 x 34) / 6) / ((52 x 51 x 50) / 6) = 99/455.
The probability that a flop has at least one of the four cards is 1 - 99/455 = 356/455, or about 78% of the time.
Something went awry with your fractions. The factorial equation is right, but it simplifies down to 147/455, or 21/65, which agrees with ME's 32.3%.
In any event, the Hold Em player did not have much respect for the others at the table. Reminds me of a coworker who stood a Coke on a desk and laid one on the ground, and measured the height between the two. He then switched the two and asked if I would bet that they had the same difference in height, with the one laid on the desk and the other upright on the ground. He said he's won hundreds at the bar from people betting that the height difference was the same.
Quote: studmuffnSomething went awry with your fractions. The factorial equation is right, but it simplifies down to 147/455, or 21/65, which agrees with ME's 32.3%.
In any event, the Hold Em player did not have much respect for the others at the table. Reminds me of a coworker who stood a Coke on a desk and laid one on the ground, and measured the height between the two. He then switched the two and asked if I would bet that they had the same difference in height, with the one laid on the desk and the other upright on the ground. He said he's won hundreds at the bar from people betting that the height difference was the same.
Please clarify: let the height of the desk be D, height of the can be H, width of the can be W, where H > W. Are you saying that the bet was D+H-W = D+W-H? If so, that's not even a math problem, just an exploit of people who are bad at spatial reasoning. I suppose it would help if the mark is drunk, but that's still just mean.
Quote: MathExtremistPlease clarify: let the height of the desk be D, height of the can be H, width of the can be W, where H > W. Are you saying that the bet was D+H-W = D+W-H? If so, that's not even a math problem, just an exploit of people who are bad at spatial reasoning. I suppose it would help if the mark is drunk, but that's still just mean.
You've got it exactly right. The kicker is that he wasn't being mean at all. He had lost money at the bar to this bet, and was so impressed that he used it to trick his friends. But even while showing me, he was still impressed at the 3-4" change and my efforts to explain proved fruitless. Very talented welder and rig operator, not much of a logician.
a) heads, tails, (doesn't matter), the last flip is a suspenseful 50-50 chance to win.
b) heads, heads, "oh no!"
Edit: we should do a bar bets thread...
Quote: MathExtremist32.3% chance to win, 67.7% to lose. Total sucker bet.
This is the correct answer. Even if you got 2:1 odds, it would still be slightly in his favor.
That's true if he's talking about 3 ranks. The way you phrased the question it sounded like 4 ranks (2,3,4,J).Quote: FatBabyKateI was eventually told by the man that offered the bet that it was approximately 55%-45% in his favor
With 4 ranks it's roughly 68-32 in his favor like the others said.
Quote: studmuffnThis is the correct answer. Even if you got 2:1 odds, it would still be slightly in his favor.
Right, but offering 2:1 would be a red flag for the mark. Better to make it even money and not raise suspicions. The fact that it yields a 35% edge is what makes it a great sucker bet.
So I'm gonna accept your answer that it will hit about 55.3% of the time. Thanks for your time!
I saw some stats somewhere, a 2 is the most common card on a flop. The reason being that players prefer to player higher ranked cards, and more flops are seen with these cards in the players hands.
