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-   -   A question I've always wanted answered. (http://archives2.twoplustwo.com/showthread.php?t=393410)

12-07-2005 12:55 PM

A question I\'ve always wanted answered.
 
You sit at a roulette table for 100 spins (just watching) and every one is black. Do I have a better chance of winning if I now put my money on red?

12-07-2005 01:03 PM

Re: A question I\'ve always wanted answered.
 
[ QUOTE ]
You sit at a roulette table for 100 spins (just watching) and every one is black. Do I have a better chance of winning if I now put my money on red?

[/ QUOTE ]
No...there is a "50%" chance of it hitting red or black on any given spin. (Of course, it's actually slightly less than 50% due to 0 and 00.)

If you were to instead ask "what are the odds of it hitting black then red?", the answer would be ~25%.

pzhon 12-07-2005 01:14 PM

Re: A question I\'ve always wanted answered.
 
There are many gambling fallacies. Some people would say that black has come up so frequently that red is "due." Some people would say that black is on a hot streak so it is more likely to come up.

The normal assumption is that the wheel has no memory, and it isn't affected by the past. If the wheel is fair, then after 100 blacks in a row the wheel is still fair and black and red are equally likely.

If you aren't 100% sure that the wheel is fair, seeing 100 blacks in a row is very strong evidence that the wheel is biased toward black, and that black is more likely than red to come up next.

LetYouDown 12-07-2005 01:50 PM

Re: A question I\'ve always wanted answered.
 
Why can't we just make this a sticky? LOL. How many times a day is this asked, in this form, or in a Martingale theory format?

mosdef 12-07-2005 02:59 PM

Re: A question I\'ve always wanted answered.
 
[ QUOTE ]
Why can't we just make this a sticky? LOL. How many times a day is this asked, in this form, or in a Martingale theory format?

[/ QUOTE ]

Well, it usually appears in the form of an ecstatic post from someone who thinks that they have discovered a way to beat blackjack (or roulette, or whatever 50/50ish game they can think of). And people that are drunk with lust for money and think they have discovered a way to beat the casino don't bother reading the stickies. They just post their genius and then sit back with visions of dollar signs dancing in their heads. Until someone explains things to them.

jkkkk 12-07-2005 03:06 PM

Re: A question I\'ve always wanted answered.
 
I'd bet on black.

Leptyne 12-07-2005 04:42 PM

Re: A question I\'ve always wanted answered.
 
The question for a gambler is what is the probability of the next three turns also coming up black. If you're observing this phenom you know this will make 103 consecutive.

The statisticians answer is always that the past has no effect on the probablility of the outcome of this event (unlike card counting, for example).

ThinkQuick 12-07-2005 05:48 PM

Re: A question I\'ve always wanted answered.
 
[ QUOTE ]

If you aren't 100% sure that the wheel is fair, seeing 100 blacks in a row is very strong evidence that the wheel is biased toward black, and that black is more likely than red to come up next.

[/ QUOTE ]


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