### Author Topic: A Common Error in Probability  (Read 76295 times)

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#### scepticus

##### Re: A Common Error in Probability
« Reply #180 on: July 28, 2015, 11:15:05 PM »

SIGH  !
Mike
Until you prove that the Birthday Problem scenario is wrong you HAVE NOT proven my derivation wrong.
Your common sense deserted you when you claimed to " prove " that the last of seven spins had less chance than the previous six which  had ZERO chance of success at that point .
Your naivety about betting roulette is shown when you clearly don't understand that the "stats" I gave  do not  refer to the 8 number sequence. So far as I am aware I gave no win rate for the 8 number sequence.
« Last Edit: July 28, 2015, 11:41:03 PM by scepticus »

#### Harryj

##### Re: A Common Error in Probability
« Reply #181 on: July 29, 2015, 10:19:07 PM »
Harry,

I don't think there's much point in me arguing with you when you're talking in generalities. I disagree with everything you say but in this case I was referring to scepticus' particular system which I have PROVEN does not work, much less has the win rate he claims.

The fact that he has wilfully ignored my proof shows that he is only interested in his agenda, not the truth. There's also no point in arguing with someone like that.

If you care to post the specific details of your system, I will show you that IT doesn't work either.

Mike,
I have posted 3 systems on the Johnson progression  The flaw thread. By all means trash them if you can.

Harry

#### Mike

##### Re: A Common Error in Probability
« Reply #182 on: July 31, 2015, 07:12:24 AM »

SIGH  !
Mike
Until you prove that the Birthday Problem scenario is wrong you HAVE NOT proven my derivation wrong.

scepticus,

I've proved in multiple ways that your system doesn't work. The one I have in mind is the file I uploaded showing that betting using the trigger of 7 non-repeats results in a winning percentage of 18.9%, which is 7/37. It was the one you dismissed when Reyth confirmed it over millions of spins because you said it was just one sample, and that the result could be completely different in another sample, thus undermining the very concept of probability, and so would render the birthday problem itself meaningless.

#### scepticus

##### Re: A Common Error in Probability
« Reply #183 on: July 31, 2015, 11:08:37 AM »
Mike
You and I look at this differently even though we agree that the Birthday Problem can be applied to roulette.
All I am saying is if in  ANY 8 of 37  there is a 53% chance of 2 being the same then ANY 2 of that 8 can be that 2.  Logic dictates that if there are no repeats in the first 7 then the 8th MUST have a better chance than the prior 6 because THEY have zero chance. Your view that it has LESS chance than the others defies common sense.
Basically, this has nothing to do with roulette but is maths APPLIED to roulette.
You misunderstand my point about Reyths' ( or anyone else's  ) million. Tell me Mike - How many variations are there in one million spins of the wheel ? Gazillions  ! and yet Reyth's is only ONE of those gazillions  and I am expected to accept that one from gazillions is an acceptable sample ?Perhaps when Reyth has given me trillions of samples I may accept that he has a point.
Probability Theory is just that Mike - a theory.Perhaps the best " guess " we have but still speculation however you dress it up. As it's very name implies it does not deal in certainties - only  likliehoods .
Get over it Mike.

#### Mike

##### Re: A Common Error in Probability
« Reply #184 on: August 02, 2015, 03:25:37 PM »

All I am saying is if in  ANY 8 of 37  there is a 53% chance of 2 being the same then ANY 2 of that 8 can be that 2.  Logic dictates that if there are no repeats in the first 7 then the 8th MUST have a better chance than the prior 6 because THEY have zero chance. Your view that it has LESS chance than the others defies common sense.
Basically, this has nothing to do with roulette but is maths APPLIED to roulette.

NO. As I have repeatedly told you, as successive spins arise you have to re-calculate the chance of at least one repeat for the remaining spins. The 53% applies to 8 spins and 8 spins ONLY.

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You misunderstand my point about Reyths' ( or anyone else's  ) million. Tell me Mike - How many variations are there in one million spins of the wheel ? Gazillions  ! and yet Reyth's is only ONE of those gazillions  and I am expected to accept that one from gazillions is an acceptable sample ?Perhaps when Reyth has given me trillions of samples I may accept that he has a point.

scepticus,

Your innumeracy is truly mind-boggling. The number of variations is completely irrelevant. Yes, there are a huge number of possible SEQUENCES (meaning the ORDER of the outcomes) in even 100 spins, but so what? It's the PROPORTION of wins versus losses, black versus red, or whatever that is relevant.

What I said still stands. If you needed that many spins to establish a stable probability then probability theory as we know it would be next to useless. Casinos wouldn't be able to operate, much less make a reliable profit.

Not only that, but your objection is a clear case of double standards. You have claimed that you have a system which has won for you more often than not (so much so that you even said the casino might change the rules if it got out LOL). Now how many times have you used it? I'm guessing the number of placed bets is not more than a few 1000. You are happy to claim that the system is probably a winner on this basis, yet a simulation which shows that your birthday system does NOT work over MILLIONS of spins is dismissed by you on the grounds that the sample is too small!

Looks like a case of heads you win, tails I lose. LOL.

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Probability Theory is just that Mike - a theory.Perhaps the best " guess " we have but still speculation however you dress it up. As it's very name implies it does not deal in certainties - only  likliehoods .
Get over it Mike.

This is a common misconception. The word "theory" does not mean what it means in common usage in a scientific context.

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In modern science, the term "theory" refers to scientific theories, a well-confirmed type of explanation of nature, made in a way consistent with scientific method, and fulfilling the criteria required by modern science. Such theories are described in such a way that any scientist in the field is in a position to understand and either provide empirical support ("verify") or empirically contradict ("falsify") it. Scientific theories are the most reliable, rigorous, and comprehensive form of scientific knowledge,

« Last Edit: August 02, 2015, 03:32:12 PM by Mike »

#### scepticus

##### Re: A Common Error in Probability
« Reply #185 on: August 02, 2015, 10:09:35 PM »
Well then , substitute Hypothesis for Theory .The answer is still the same.
What I said was that the  method  I use  won more than it lost. IN REAL TIME - not in the airy - fairy Infinite time  you claim .
And there ARE gazillions of  possibilities in a million spins of the wheel so ONE or even a MILLION millions is still insufficient to be classed as an acceptable sample. You are too stuck up in hypothesis to come into the real world. Mathematicians can only claim  that we are LIKELY to lose in INFINITE time. It is utter nonsense to even imagine that any human being will live until infinity. I repeat - anyone who claims that we MUST lose is overstating his or her case.
AS for any  8 number series. Are you really saying that someone who bets from bet one without encountering a repeat has a BETTER chance than someone who has come late to the party and bets only the 8th ?  If the maths is that over the 8 spins the chance of ANY 2 being the same ha a 53 % chance of being successful then that applies to all 8 .look again at the Wiz's  calculations - they tell a completely different story to yours.
look again at the Birthday Problem. Strange as it may appear,in  a sequence of  22 there is less tha a 50% chance of a repeat while a 23 sequence has a 53% chance so , obviously, the more numbers that appear the better the chance of a repeat .Apply this to roulette and there is a need for 8 rather than 7  = as the WIZ's chart shows . Your chart shows that there is LESS chance as the spins progress -which defies comm0n sense. And you claim that MY innumeracy is truly mind boggling  ! Extend that 8 spin sequence to a 10 spin sequence and there is an INCREDIBLE 95% chance of a repeat. ! Isn't THAT mind- boggling  ?
Probability Theory IS useless if it needs an INFINITE number of spins which is why mathematicians need to use a " cut-off point"  -which can only be an assumption which is beyond your comprehension since  you don't know the difference between an" Assumption " and a "Given " .
If there is a 53 % chance of ANY 8 showing a repeat then there it is HIGHLY LIKELY that there will  be a profit after a millions spins ASSUMING that a million spins  is a sufficient  sample. And I have made it clear that I do NOT bet the 8 number bet .  I am too impatient to wait for a 7 series to appear.
The Birthday Problem conclusion IS hard to accept . but if it is true then so is my 8th bet  as it too, sets a parameter.
The Best of Luck in living to infinity !
« Last Edit: August 02, 2015, 11:19:11 PM by scepticus »

#### Mike

##### Re: A Common Error in Probability
« Reply #186 on: August 03, 2015, 07:33:09 AM »
Well then , substitute Hypothesis for Theory .The answer is still the same.

No it isn't. Did you actually read the quote or watch the vid?

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What I said was that the  method  I use  won more than it lost. IN REAL TIME - not in the airy - fairy Infinite time  you claim .

Now you're putting words into my mouth. Where did I ever say that the you need an infinite number of spins? You don't. This is just mathematician speak for "the long run". Rather than put a specific number on the "long run" which might be misleading, they use the mathematical abstraction of infinity. In fact, empirical results show that the theoretical probabilities are approximated quite quickly, in a matter of 100's or 1000's of spins.

If you don't believe me, learn how to code and find out for yourself. Reyth has just started a thread on programming in BASIC.

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AS for any  8 number series. Are you really saying that someone who bets from bet one without encountering a repeat has a BETTER chance than someone who has come late to the party and bets only the 8th ?  If the maths is that over the 8 spins the chance of ANY 2 being the same ha a 53 % chance of being successful then that applies to all 8 .look again at the Wiz's  calculations - they tell a completely different story to yours.

No they don't. It's just that you haven't understood.

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look again at the Birthday Problem. Strange as it may appear,in  a sequence of  22 there is less tha a 50% chance of a repeat while a 23 sequence has a 53% chance so , obviously, the more numbers that appear the better the chance of a repeat .

Yes, that's exactly what I was saying a few post ago.

Quote
Your chart shows that there is LESS chance as the spins progress -which defies comm0n sense. And you claim that MY innumeracy is truly mind boggling  !

Yes, because once spins have spun, they no longer contribute to the original sequence. You are still stuck in the gambler's fallacy and seem incapable of grasping it. Too bad.

Quote
Extend that 8 spin sequence to a 10 spin sequence and there is an INCREDIBLE 95% chance of a repeat. ! Isn't THAT mind- boggling  ?

It would be if you had a 95% chance of a win when betting on 9 numbers, but you don't. The chance is 9/37.

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Probability Theory IS useless if it needs an INFINITE number of spins

I agree, but it doesn't. Again, see for yourself by writing your own programs.

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If there is a 53 % chance of ANY 8 showing a repeat then there it is HIGHLY LIKELY that there will  be a profit after a millions spins ASSUMING that a million spins  is a sufficient  sample.

No it isn't. It's highly UNLIKELY that there will be a profit after only a few hundred bets. Having reached the point of no return, the hole will only get deeper as you place more bets.

Learn to code and try it for yourself. It's pointless me doing it for you because you'll just ignore it or come back with some absurd objection.
« Last Edit: August 03, 2015, 07:36:53 AM by Mike »

#### scepticus

##### Re: A Common Error in Probability
« Reply #187 on: August 03, 2015, 10:21:30 AM »
Mike
1 ) We agreed that it was valid to transfer the Birthday Problem to Roulette.
2 ) We don't agree on the probabilities increasing after each non- repeat.You think they decrease while I think they increase. ( The Wiz agrees with me here  )( as does Yale on " Given )
We are never going to agree on this Mike so I am going no further.Like Real said on another thread I'll leave it up to the members to decide.

#### MickyP

##### Re: A Common Error in Probability
« Reply #188 on: May 31, 2019, 10:43:06 AM »
In line with recent discussions on the forum I think this old thread is a gem.

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