AA, KK etc twice in a row

[Saborion]

The chance of getting dealt a specific pocket pair is 1:221 right? What`s the probability that you`re dealt the same pair again (neglecting suits)? This is something I`ve always had problem understanding.

If you flip a coin, you have a 50/50 chance of getting tails, it really doesn`t matter what the outcome was of the previous flip was, does it? Even so, the probability of getting two tails in a row is .5*.5 = .25? So, it I do get tails on the first attempt, is it only 25 % chance that I get tails again, or is it 50 %?

[Henke]

[ QUOTE ]

If you flip a coin, you have a 50/50 chance of getting tails, it really doesn`t matter what the outcome was of the previous flip was, does it? Even so, the probability of getting two tails in a row is .5*.5 = .25? So, it I do get tails on the first attempt, is it only 25 % chance that I get tails again, or is it 50 %?

[/ QUOTE ]

You have to be very strict when defining a mathematical problem. If you ask for the probability of getting two tails on two consecutive flips, the probability is 25%, but if you ask the probability of getting a tail when you know you've just had a tail, it's 50%, because the coin has no "memory".

So the probability of getting dealt AA two consecutive deals is mathematicaly not the same as the probability of getting AA the next deal, when you had AA on this one. (The cards have no memory neither.)

[Saborion]

Sort of interesting.
I mean, say I`m sitting in a tourny where a guy just had AA and busted another player. Now on the next hand I`m dealt KK and is up against that same player. Is the probability that he has AA again (1/221)*(1/221) or is it 1/221? Both answers are true, in their own ways right? Although in this case I`d say it`s 1/221 due to the no memory. Or am I wrong then? /images/graemlins/smile.gif

[mojito]

the coin problem reminds me of a continual argument with one of my friends about the black/red bet on a roulette...
he sees 9 previous blacks on a roulette display and he tells me that it is more probable now that a red will hit... and i can't stop repeating to him that the probability is always 50%, regardless of the history...

just checking if u guys agree with me.

[Henke]

Try asking your friend if he agrees to take a bet with a 3:2 proposition, so that you get $3 from him if a 10:th red comes, and he get $2 from you if a black comes. That should make you some money!

[flopdanutz]

when u hold KK the prob of a specific player holding AA is
(4/50) * (3/49) or 0.489% slightly higher than 1/221
because you are holding two non aces which increases the chance that your opponent has an ace.

if u did not peek at your cards (thus not knowing the cards your opponent cannot have) then the probability of your opponent having AA would be 1/221

[OldLearner]

What if the Question were:

At this specific moment, what are the odds that I will dealt AA in the next hand and the hand after?

What about:

At this specific moment, what are the odds that I will dealt AD AH in the next hand and the hand after?

[Zetack]

I once sat down, waited for the big blind, posted and was dealt KK. On my third hand, I got KK again. Then I had KK within the next circuit of cards. (I actually lost all three times--grrrrrrr).

So, in a vaguely related question, what are the odds of getting KK three times in your first 12 hands?

--Zetack