View Full Version : bad beat quiz

01-16-2005, 09:35 AM
Hi all!

I'll give 2 scenaros of cards and flops- which has the longer odds to happen and what are odds and how did you calculate them- enjoy.

You have JJ, other guy has AA- both allin preflop. Flop is Axx. What are your odds to beat him- no flushes or straights possible.

Next scenario - You have JQd, opponent has 56d. Flop is
789d. What are your odds to beat him.

Online today, I overcame one of the two examples to win- I overcame the one with longer odds- which one is it and how did you calculate.

01-16-2005, 03:47 PM
The first scenario is a longer shot because you need to catch 2 perfect cards, and in the second scenario you only need to catch 1 perfect card.

01-17-2005, 02:36 AM
Hand #2 first: You need to catch the Td. Two cards to come with 9 known cards. The math is 2/43 + 1/42 = 3/85 which reduces to 1/28.33. That is odds of 27.33:1 BTW, it does not crack a jackpot. See why?

Hand #1: You need one jack without opponet catching a ace. This one has been published many times. It is 999:1

01-17-2005, 05:33 AM
Hand one - you need running Jacks. 7 known cards. 45 unknown. 2/45 * 1/44 = 1/990

Hand 2 - You need the 10 /images/graemlins/diamond.gif. You have two chances to get it. 1/45 = .0222% 1/44=.0227 1/45+1/44= .0449 or 4.49% chance it will hit.

(thanks for eliminating the possibility of str8 or flush on the first one)


01-17-2005, 01:08 PM
Scenario 1

In addition to "no flushes or straights possible", we must also assume that "xx" on the board is not a pair, otherwise there is a remote possibility of a split if the final board shows 4 of a kind (i.e. Axxxx).

So you need running J's on both turn AND river, 45 cards unseen:

2/45 * 1/44 = 1/990

Odds: 989:1

Scenario 2

You need the Td on either the turn OR the river. This makes the math a bit different; when calculating an OR scenario, you calcuate the chances of your desired outcome NOT happening on the turn AND NOT happening on the river and then subtract this from 1. Again, 45 cards unseen:

chances of Td NOT coming on the turn = 44/45
chances of Td NOT coming on the river (after not coming on the turn) = 43/44

total chance of missing Td = 44/45 * 43/44 = 43/45
total chance of catching Td = 1 - 43/45 = 2/45

Odds: 43:2 = 21.5:1