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View Full Version : once the cards are shuffled, arent the odds just the same


FrontonPoker
04-13-2005, 11:25 AM
what im asking is this: the cards are shuffled, i get AA..
the next hand is dealt, the odds of getting AA AGAIN are just the same, previous hands dealt have no influence on the next deal.. if i shuffle the deck, and take the top card, say its A /images/graemlins/spade.gif, the odds of that happening are 1 in 52.. i shuffle again, the odds of getting the A /images/graemlins/spade.gif are again 1 in 52, am i correct in this thinking?

mostsmooth
04-13-2005, 11:31 AM
absolutely correct

deacsoft
04-13-2005, 12:05 PM
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absolutely correct

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Larimani
04-13-2005, 10:28 PM
noway dood, the chances of getting the same card get much smaller the second time. You see, the deck holds a sort of unconscious memory and reduces your chances of getting the same card. The odds are reduced by an amount proportional to the suit of the card.
For spade cards the odds become 1/53
For hearts, 1/54
For diamonds, 1/55
and this is the interesting part: for clubs, there is only a 1% chance of picking up the same card...

This is the same problem as the roulette problem. Let's assume there is no 0 or 00... what are the chances of the ball landing on red? 50%... that's right...

Now let's assume the ball has landed on red 5 times in a row, what are the chances that it lands on red again. the answer is 40%

If the ball lands on red 10 times in a row, now the probability of it landing on red again is 20%!! It is by observing these patterns that roulette professionals can make thousands of dollars every day...

Terry
04-13-2005, 10:37 PM
Very good. Now answer this:

What are the odds you will shuffle the deck and pick the A /images/graemlins/spade.gif twice in a row?

Larimani
04-13-2005, 11:56 PM
0%, because once you've removed the A /images/graemlins/spade.gif there is no A /images/graemlins/spade.gif left in the deck.

emp1346
04-14-2005, 12:50 AM
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0%, because once you've removed the A /images/graemlins/spade.gif there is no A /images/graemlins/spade.gif left in the deck.

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i'm pretty sure you're A) missing the question and B) wrong...

first of all, read the original question and you'll see that this is obviously with replacement...

secondly, and pay attention to this one, if you draw the A/images/graemlins/spade.gif and replace it, and truly shuffle the deck to the point that it is random again and independent of the previous draw / shuffle, the odds of drawing the A/images/graemlins/spade.gif is the same every time...

it should theoretically work the same as independent trials...

mostsmooth
04-14-2005, 01:04 AM
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0%, because once you've removed the A /images/graemlins/spade.gif there is no A /images/graemlins/spade.gif left in the deck.

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i'm pretty sure you're A) missing the question and B) wrong...

first of all, read the original question and you'll see that this is obviously with replacement...

secondly, and pay attention to this one, if you draw the A/images/graemlins/spade.gif and replace it, and truly shuffle the deck to the point that it is random again and independent of the previous draw / shuffle, the odds of drawing the A/images/graemlins/spade.gif is the same every time...

it should theoretically work the same as independent trials...

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im prety sure youre both wrong regarding terrys question

unimproved
04-14-2005, 04:14 AM
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0%, because once you've removed the A /images/graemlins/spade.gif there is no A /images/graemlins/spade.gif left in the deck.

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i'm pretty sure you're A) missing the question and B) wrong...

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Just a wild guess but from the tone of the posts I think he actually might be C) joking :P

FrontonPoker
04-14-2005, 08:50 AM
sorry i wasnt specific.. once the hand is OVER and the cards are RESHUFFLED.. i shuffle the deck, the top card is A /images/graemlins/spade.gif, i put it back INTO the deck, RESHUFFLE, the odds are still 1 in 52... im coming from the angle of i get QQ one hand, the hand is over, the next deal is again, QQ

unimproved
04-14-2005, 10:08 AM
Assuming the shuffle randomises the deck, the odds are the same. Why would they be any different..?

OrangeKing
04-14-2005, 12:05 PM
[ QUOTE ]
Assuming the shuffle randomises the deck, the odds are the same. Why would they be any different..?

[/ QUOTE ]

I'm guessing he got into an argument with someone who doesn't understand what random means, and thinks there's an even distribution - i.e., if you get AA one hand, you shouldn't see it again for about another 220 hands. Which is of course, silly.

So yeah, if you get AA ten hands in a row, the odds of getting it on the 11th hand are still 220-1. However, the odds of getting AA 11 times in a row (before you've seen even 1 AA come) are 58431830141132800000000000 to 1. Approximately. /images/graemlins/smile.gif

jason_t
04-14-2005, 12:40 PM
[ QUOTE ]
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Assuming the shuffle randomises the deck, the odds are the same. Why would they be any different..?

[/ QUOTE ]

I'm guessing he got into an argument with someone who doesn't understand what random means, and thinks there's an even distribution - i.e., if you get AA one hand, you shouldn't see it again for about another 220 hands. Which is of course, silly.

So yeah, if you get AA ten hands in a row, the odds of getting it on the 11th hand are still 220-1. However, the odds of getting AA 11 times in a row (before you've seen even 1 AA come) are 58431830141132800000000000 to 1. Approximately. /images/graemlins/smile.gif

[/ QUOTE ]

Actually it is 61420735191082762650784420:1.

FrontonPoker
04-14-2005, 01:07 PM
[ QUOTE ]
[ QUOTE ]
Assuming the shuffle randomises the deck, the odds are the same. Why would they be any different..?

[/ QUOTE ]

I'm guessing he got into an argument with someone who doesn't understand what random means, and thinks there's an even distribution - i.e., if you get AA one hand, you shouldn't see it again for about another 220 hands. Which is of course, silly.

So yeah, if you get AA ten hands in a row, the odds of getting it on the 11th hand are still 220-1. However, the odds of getting AA 11 times in a row (before you've seen even 1 AA come) are 58431830141132800000000000 to 1. Approximately. /images/graemlins/smile.gif

[/ QUOTE ]

yes, thats how it came up, someone was mussing about having to fold AA to a flush on the board, and asked, what are the chances i will get dealt the same hand, and i said the same as the hand before (you were dealt them) and he insisted the the 'odds were longer' since he just had them, the odds of being dealt them again are less, and i was saying its still the same, every deal is independent of previous deals..

YouGotBluffed
04-14-2005, 02:26 PM
You guys are correct with all but one thing I believe. We all know a deck has no supernatural power to know if person #1 just got AA last hand, and therefore shouldn't have it again for another 20 hands or so.


However, the first question asked, what are the chances that you will pull the Ace of Spades out of the deck twice in a ROW. If the question hadn't specified twice in a ROW, then the odds of course would be the same because the cards are independent from previous and future hands. But, because it was specific, I believe you have to take 1/104 which yields a .009% chance of pulling the Ace of Spades out twice in a row. In other words, you would have to pull out a card 90,000 times (reshuffling after each time of course) before you pull out the same card twice in a row.

I think that's right.

mostsmooth
04-14-2005, 08:32 PM
[ QUOTE ]
You guys are correct with all but one thing I believe. We all know a deck has no supernatural power to know if person #1 just got AA last hand, and therefore shouldn't have it again for another 20 hands or so.


However, the first question asked, what are the chances that you will pull the Ace of Spades out of the deck twice in a ROW. If the question hadn't specified twice in a ROW, then the odds of course would be the same because the cards are independent from previous and future hands. But, because it was specific, I believe you have to take 1/104 which yields a .009% chance of pulling the Ace of Spades out twice in a row. In other words, you would have to pull out a card 90,000 times (reshuffling after each time of course) before you pull out the same card twice in a row.

I think that's right.

[/ QUOTE ]
where does it say twice in a row?

YouGotBluffed
04-14-2005, 09:58 PM
[ QUOTE ]
[ QUOTE ]
You guys are correct with all but one thing I believe. We all know a deck has no supernatural power to know if person #1 just got AA last hand, and therefore shouldn't have it again for another 20 hands or so.


However, the first question asked, what are the chances that you will pull the Ace of Spades out of the deck twice in a ROW. If the question hadn't specified twice in a ROW, then the odds of course would be the same because the cards are independent from previous and future hands. But, because it was specific, I believe you have to take 1/104 which yields a .009% chance of pulling the Ace of Spades out twice in a row. In other words, you would have to pull out a card 90,000 times (reshuffling after each time of course) before you pull out the same card twice in a row.

I think that's right.

[/ QUOTE ]
where does it say twice in a row?

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Sorry, Terry said:

"Very good. Now answer this:

What are the odds you will shuffle the deck and pick the A (of spades) twice in a row?"

Breitenfeld
04-14-2005, 10:30 PM
Just tell us, how much money did you already lose with your conclusions????

Breitenfeld
04-14-2005, 10:35 PM
You are absolutely right. Once you have the A /images/graemlins/spade.gif, for the next game it's exactly 1 in 52. Only if you want to know the probability of getting it two times in a row, without knowing what will happen the first time, than you have to calculate 52 x 52 = 2704.
All speculations about so-called "emperical probabilities" are nothing but wishful thinking, otherwise all casinos would have already gone bancrupt!

Cincy Peach
04-14-2005, 10:39 PM
Of course you are correct. Some of the responses to your question were kind of flippant, but it's a darned good question, because the falacy you refer to just won't go away.

I read a book once where the author seriously referred to 'the law of the maturity of chances'(!) in promoting some particular betting system. The idea that someone that wrong could get published amazed me. There are no 'trends'; you're never 'due'. Furthermore this 'law' is so fundamentally ingrained in some people that you can't convince them otherwise. Don't let them sway you, though, just nod and smile when they spout there nonsense.

YouGotBluffed
04-14-2005, 11:05 PM
[ QUOTE ]
You are absolutely right. Once you have the A /images/graemlins/spade.gif, for the next game it's exactly 1 in 52. Only if you want to know the probability of getting it two times in a row, without knowing what will happen the first time, than you have to calculate 52 x 52 = 2704.
All speculations about so-called "emperical probabilities" are nothing but wishful thinking, otherwise all casinos would have already gone bancrupt!

[/ QUOTE ]

Whoops, you are right. I added them instead of multiplying (52+52=104 whereas 52x52=2704)

Thus 1/2704=.0003, which means you'd have to take a card from the deck and reshuffle after each time 3 million times before you'd pull out one twice in a row. /images/graemlins/tongue.gif

Terry
04-15-2005, 12:01 AM
Almost there. What are the odds? Not the probability [percent of times it will happen] what are the odds?

emp1346
04-15-2005, 01:35 AM
[ QUOTE ]
Almost there. What are the odds? Not the probability [percent of times it will happen] what are the odds?

[/ QUOTE ]

what are the odds that no matter what anyone responds there'll be someone who doesn't agree? hmmm....

YouGotBluffed
04-15-2005, 02:13 AM
[ QUOTE ]
Almost there. What are the odds? Not the probability [percent of times it will happen] what are the odds?

[/ QUOTE ]
Oh, well 1 outta 3 million. I don't see what the difference is though, I just worded it differently.

Terry
04-15-2005, 03:00 AM
Its not 3,000,000 to 1 ... not even close ... that is why the terminology is important in understanding the concept.

mostsmooth
04-15-2005, 10:28 AM
im an idiot, but im going with 2703 to 1. (the 2703 based on the other persons math work, im not going to check it)

YouGotBluffed
04-15-2005, 02:23 PM
[ QUOTE ]
Its not 3,000,000 to 1 ... not even close ... that is why the terminology is important in understanding the concept.

[/ QUOTE ]
How is it not? I think you're misunderstanding. The words proability and odds are interchangable, at least for this situation.


"The odds of pulling the same card from the deck twice in a row is three million to one" means the same as "The proability of pulling the same card from the deck twice in a row is three million to one."


Or, like I already said, you'd have to pull out a card three million times before you pulled the same card out twice in a row.

gergery
04-15-2005, 04:56 PM
[ QUOTE ]
if i shuffle the deck, and take the top card, say its A /images/graemlins/spade.gif, the odds of that happening are 1 in 52.. i shuffle again, the odds of getting the A /images/graemlins/spade.gif are again 1 in 52, am i correct in this thinking?

[/ QUOTE ]

The probability that you get the Ace spades is 1 in 52, or 1.92%

The odds that you get the Ace spades is 1 to 51 against.

These are different.

Terry
04-15-2005, 08:42 PM
So regarding our question:

The odds are 2703 to 1 against. (52*52)-1

The probability (or chance) it will happen is 0.000369822 or 0.0369822%. (1/(52*52))

These both mean the same thing but stating it as odds appears to make the answer clearer in this case.

Raydain
04-15-2005, 10:17 PM
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absolutely correct

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thread should have ended here

Terry
04-16-2005, 02:49 AM
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thread should have ended here

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Right. No sense trying to help people learn or understand why ... nobody wants to hear that crap.

Actually I think the thread has only one useless post yours.

Raydain
04-16-2005, 03:11 AM
I believe the poster already knew why and just wanted to be reassured. It does not help to say random = random.

YouGotBluffed
04-16-2005, 02:08 PM
[ QUOTE ]
So regarding our question:

The odds are 2703 to 1 against. (52*52)-1

The probability (or chance) it will happen is 0.000369822 or 0.0369822%. (1/(52*52))

These both mean the same thing but stating it as odds appears to make the answer clearer in this case.

[/ QUOTE ]

Ok, so you'd have to pick a card from the deck 30,000 times before you pulled out the same one twice. /images/graemlins/tongue.gif

Terry
04-16-2005, 05:00 PM
If youre serious about the 30,000 youre still not getting it.

You will pick the same card twice once out of 2704 tries.

jason_t
04-16-2005, 05:14 PM
[ QUOTE ]
[ QUOTE ]
Its not 3,000,000 to 1 ... not even close ... that is why the terminology is important in understanding the concept.

[/ QUOTE ]
How is it not? I think you're misunderstanding. The words proability and odds are interchangable, at least for this situation.


"The odds of pulling the same card from the deck twice in a row is three million to one" means the same as "The proability of pulling the same card from the deck twice in a row is three million to one."


Or, like I already said, you'd have to pull out a card three million times before you pulled the same card out twice in a row.

[/ QUOTE ]

This last paragraph is wrong. That is not what probability means.