Wednesday, February 08, 2006


If you have ever been at casino, you have probably seen the table of the last occurred numbers at roulette..

Also, at Lotto and other games where the player selects numbers, some people keep track of the latest results..

There are 2 totally contradicting points of view.
There are the people that believe that it is meaningfully to keep track of the results
and there are these people that say that it is stupid..

Let's use a perfect dice to explain the two ways of thinking..
(by perfect I mean that you cannot foresee the result of rolling the dice.)

The defenders of the first opinion, say that if you roll the dice A times(A should be BIG number), the number of times you get the "1" should be about A/6. And as A increases(we roll the dice more and more times), the “probability of getting "1" A/6 times gets higher.
So, If we have rolled a dice 20 times and we see that all the times we got "1", it is very likely that "1" will not come the next time, because the other numbers have to occur as well with about the same probability if we were to roll the dice 100 times for example.. And if we get "1" again, then the probability to get any other number, increases comparing to the probability to get "1" again.

But, others believe that all the above analysis makes no sense since the experiments are independent from each other. That means, that the rolling of a dice one more time, has nothing to do with the result of the previous rolling..

I hope I made myself clear.
I guess that the second view is the correct one..


Zafiris said...

unfortunately, there is actually only ONE point of view. Roulette is a game withoug memory, so the next spin is totally independent from the spins before it... everything else is bullshit... "Point of view" does not enter into it. Either you get what statistics is about, or you don't

Stavros said...

I am just trying to be diplomatic..

psarog said...

Yes,Zaf is right. Otherwise the casinos wouldn't have this result table ;)