MCR
MCR
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September 9th, 2025 at 8:59:09 PM permalink
A Texas Hold'em game is offering jackpot that is won on Royal Flush. RF on Flop pays 100%, on Turn 20%, and on River 10%. The "catch" is that the player has to use their own two cards to form a RF.
The question is, what are the odds of hitting RF on Turn and on River, if the player has to use their original two cards.
It would be greatly appreciated if somebody could share how these two values can be calculated.
SkinnyTony
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September 9th, 2025 at 9:25:33 PM permalink
Didn't you already ask about this here? https://wizardofvegas.com/forum/questions-and-answers/advice/41520-texas-holdem-jackpot/#post961644
Last edited by: SkinnyTony on Sep 9, 2025
aceside
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September 9th, 2025 at 11:52:04 PM permalink
At River, it’s C(52,5)/C(5,3)=649740/10=64,974, so 1 in 64,974.
At Turn, it’s C(52,5)/C(4,3)=649740/4=162,435, so 1 in 162,435.
Last edited by: aceside on Sep 10, 2025
SkinnyTony
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September 10th, 2025 at 1:53:16 PM permalink
Quote: aceside

At River, it’s C(52,5)/C(5,3)=649740/10=64,974, so 1 in 64,974.
At Turn, it’s C(52,5)/C(4,3)=649740/4=162,435, so 1 in 162,435.
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I believe that this is incorrect
aceside
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September 10th, 2025 at 2:25:32 PM permalink
People have different numbers, but I believe these two numbers are correct.
ChesterDog
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aceside
September 10th, 2025 at 5:17:11 PM permalink
Quote: MCR

A Texas Hold'em game is offering jackpot that is won on Royal Flush. RF on Flop pays 100%, on Turn 20%, and on River 10%. The "catch" is that the player has to use their own two cards to form a RF.
The question is, what are the odds of hitting RF on Turn and on River, if the player has to use their original two cards.
It would be greatly appreciated if somebody could share how these two values can be calculated.
link to original post



I get the following numbers for my probabilities of getting the bonuses:

Royal on the flop: 1 in 649,740

Royal on the turn: 1 in 216,580

Royal on the river: 1 in 108,290

Any of the above: 1 in 64,974
aceside
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September 10th, 2025 at 5:30:53 PM permalink
Interesting! I haven’t talked to you for some time.

Royal on the flop: 1 in 649,740

Royal on the turn: 1 in 216,580

What is the probability of any of the above?
ChesterDog
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September 10th, 2025 at 5:52:23 PM permalink
Quote: aceside

Interesting! I haven’t talked to you for some time.

Royal on the flop: 1 in 649,740

Royal on the turn: 1 in 216,580

What is the probability of any of the above?
link to original post



I get 1 in 162,435 (as the probability of my getting a royal on the flop or the turn using both my hole cards.)

I see 1 in 162,435 in your post as the probability of getting a royal on the turn.
aceside
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ChesterDog
September 10th, 2025 at 5:59:34 PM permalink
I actually have had both. One of them was a six-card A-K-Q-J-10-9 flush in the first six cards. I will publish this picture someday!
SkinnyTony
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ChesterDog
September 10th, 2025 at 8:11:43 PM permalink
First you need to start with 2 royal cards. Call this probability p

p = 4 * C(5,2) / C(52,2)
= 40 / 1326
= 20 / 663

Then once you start with 2 royal cards you need to hit the royal.

P(flop royal) = p / C(50,3)
= p / 19,600
= 1 / 649,740

P(turn royal) = p * P(flop 2 to royal) * P(hit turn)
= p * (C(3,2) * 47 / C(50,3)) * (1/47)
= p * C(3,2) / C(50,3)
= 3p / 19,600
= 1 / 216,580

P(river royal) = p * P(4 to royal on turn) * P(hit river)
= p * (C(3,2) * C(47,2) / C(50,4) ) * 1 / 46
= p * (3243 / 230,300) * (1/46)
= 1 / 108,290

So I agree with ChesterDog's numbers.
aceside
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September 10th, 2025 at 9:24:55 PM permalink
If you define “on” that way, I will update my calculation too.

Must on River, it’s C(52,5)/C(4,2)=649740/6=108,290.
Must on Turn, it’s C(52,5)/C(3,2)=649740/3=216,580.
SkinnyTony
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aceside
September 10th, 2025 at 9:46:42 PM permalink
Quote: aceside

If you define “on” that way, I will update my calculation too.

Must on River, it’s C(52,5)/C(4,2)=649740/6=108,290.
Must on Turn, it’s C(52,5)/C(3,2)=649740/3=216,580.
link to original post



C(52,5) is not 649,740. It's 4x that amount. You may be thinking of the odds of getting a royal in 5 cards -- that's not C(52,5) (there are 4 ways to make a royal in 5 cards -- 1 for each suit)
aceside
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September 10th, 2025 at 9:57:13 PM permalink
Oh, I see. Let me revise.

Must on River, it’s (1/4)xC(52,5)/C(4,2)=649740/6=108,290.
Must on Turn, it’s (1/4)xC(52,5)/C(3,2)=649740/3=216,580.

At River, it’s (1/4)xC(52,5)/C(5,3)=649740/10=64,974.
At Turn, it’s (1/4)xC(52,5)/C(4,3)=649740/4=162,435.
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