### Author Topic: A Common Error in Probability  (Read 75061 times)

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#### Bayes

##### Re: A Common Error in Probability
« Reply #15 on: April 27, 2015, 12:12:45 PM »
So my question in your example is this. Is the probability of a repeat in 8 spins still 56%, after  missing the first 6 spins?  (Yes the betting process started form spin 1). The probability of series specifies a specific percentage of at least one success in a preplanned 8 series of bets. That percentage does not and should not change just because the first 6 spins missed the target.

Yes, the probability of a repeat in 8 spins is always the same, but this is irrelevant to past spins, the probability of which is always 1, assuming we know what the outcomes were, of course.

Again, I have to stress that the error made by scepticus and many others, is that you cannot assign a probability of a complete series to the next single outcome, or part of that series. What's past is gone, and probability does not apply, certainty does.

So on the 8th spin the chance of any of the previous 7 numbers repeating is 1x 1 x 1 x 1 x 1 x 1 x 1 x 7/37 ~ 19%, not 56%.

The casino does not let us bet directly on a series; we have to bet one spin at a time. And even if it did, they would adjust the payouts accordingly so that they have the edge.

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when it comes to roulette and short data probability is always WRONG. And that's what a smart player can take advantage of.

In a sense, you're correct. Probability is an average and averages become more meaningful as the sample size increases, but the "best guess" for the next single outcome is the average. If this were not true, the probability of a series would also be wrong, since it is by definition the probability of a sequence of SINGLE events.

Also, the concept of variance is needed to complete the picture. A data set is specified by the average and also the variance (how much the data is "spread out" around the average). All this can be quantified quite precisely.

And I don't see how you can take advantage of something being wrong if you don't know what is RIGHT!  If you know nothing about how likely the next outcome is, as you say probability cannot tell you this, then how does this help or give any advantage? In that case you can say nothing at all, and you may as well bet randomly.

#### dobbelsteen

##### Re: A Common Error in Probability
« Reply #16 on: April 27, 2015, 12:30:30 PM »
I will not say I am a smart player, but I take my advantage of the knowledge of the short run theory.

#### Bayes

##### Re: A Common Error in Probability
« Reply #17 on: April 27, 2015, 02:57:41 PM »
dobbelsteen, what is the difference between the short run theory and the long run theory? Isn't the short run theory just the long run theory applied to the short run?

The thing is, probability is just so basic a concept that it's hard to define, although everyone knows what it means. You might remember that guy Ashley Revell who some years ago went to LV and put his entire life savings on red. But if probability theory is WRONG in the short term, why didn't he put all his money on number 17? After all, the payoff is much higher!

But of course, you don't need to be a math geek to realize that your chance of success is much higher betting on an even chance, even when betting just one spin.

But still, he was foolish not to find a single-zero wheel.

#### palestis

##### Re: A Common Error in Probability
« Reply #18 on: April 27, 2015, 07:26:12 PM »
So my question in your example is this. Is the probability of a repeat in 8 spins still 56%, after  missing the first 6 spins?  (Yes the betting process started form spin 1). The probability of series specifies a specific percentage of at least one success in a preplanned 8 series of bets. That percentage does not and should not change just because the first 6 spins missed the target.

Yes, the probability of a repeat in 8 spins is always the same, but this is irrelevant to past spins, the probability of which is always 1, assuming we know what the outcomes were, of course.

Again, I have to stress that the error made by scepticus and many others, is that you cannot assign a probability of a complete series to the next single outcome, or part of that series. What's past is gone, and probability does not apply, certainty does.

So on the 8th spin the chance of any of the previous 7 numbers repeating is 1x 1 x 1 x 1 x 1 x 1 x 1 x 7/37 ~ 19%, not 56%.

The casino does not let us bet directly on a series; we have to bet one spin at a time. And even if it did, they would adjust the payouts accordingly so that they have the edge.

Quote
when it comes to roulette and short data probability is always WRONG. And that's what a smart player can take advantage of.

In a sense, you're correct. Probability is an average and averages become more meaningful as the sample size increases, but the "best guess" for the next single outcome is the average. If this were not true, the probability of a series would also be wrong, since it is by definition the probability of a sequence of SINGLE events.
Wait a minute now. Y do we have probability of series, if according to your reasoning is being canceled after every spin? and it turns to a probability of a single event? Just because I bet one spin at a time? What if I lay out an amount enough to cover 8 spins and instruct a robot to bet after every spin? The moment I decide to commence a series of bets and stop at any time I hit the target once, then I am locked into the series. Not the single event. And the key word is hit at least once. I don't aim to hit all or half or three of the 8 spins. Just one at any point in the 8 bet range. Then my mission is over. A single event implies the expectation to hit the next spin according to the probability of the expected result happening. But this is not the case if you decide in advance to bet a series of bets and terminate them when the target is hit at least once.
1x1x1x1x1x1x1x 7/37 is only valid if you happen to see a score board and there is no repeat 7 times, and bet the 8th spin. When you see something already formed is not part of a series because it happened without your input. The probability of series counts only when you are there from the beginning and apply your guessing power or luck from SPIN 1. Not from spin #8. Can you name a situation where the probability of series applies, without betting after every spin?
You can only bet one spin at a time, flip a coin once at a time. Scratch a lottery ticket one at a time.
There in no such thing as betting a series at once as a bulk bet. and if you bet in several roulettes at the same time, then this is not a series bet. It is a multiple single bet.
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As far as taken advantage of the wrongness of probability in the short run there is a word for it. EXPERIENCE AND RESEARCH. It doesn't have to be what's missing and what is due. It could be following an obvious  trend. Or many other things that only experience can pinpoint.
In my systems what is RIGHT is to hit the target just once. I don't  aim in continuous wins. One hit and abandon. That's not too much to ask.
I find these issues extremely important and I am glad I have resolved them.
Whether I will win one of the series of bets is the LEAST of my worries, that's y I am not searching for a winning system. My Biggest worry is when the time comes to bet, if someone else is using cash chips for inside bets, which prevents me from betting. The least I am concerned with is whether I'll win one of the next few bets. The expected result is crystal clear to me, and if  the rare event happened, I only lose very little because I stop on time. easily recoverable in the next round.
« Last Edit: April 27, 2015, 07:44:37 PM by palestis »

#### Real

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##### Re: A Common Error in Probability
« Reply #19 on: April 27, 2015, 08:22:37 PM »
Quote
Again, I have to stress that the error made by scepticus and many others, is that you cannot assign a probability of a complete series to the next single outcome, or part of that series. What's past is gone, and probability does not apply, certainty does. -Slacker

Slacker,

Above is the biggest problem confronting many gambler's.  The logic required to comprehend it is just out of reach for most of them.  No matter how many different ways you explain it, they can't grasp it.  There's a level of intellect that is missing that prevents them from ever fully understanding it, and accepting it.  Try as you might, you will never convince most of them.

It's often been said by public officials that taxes on gambling and cigarettes is a tax on the poor and ignorant.  They're not entirely wrong.   The gambler's fallacy is part of that proof.
« Last Edit: April 27, 2015, 08:29:56 PM by Real »

#### palestis

##### Re: A Common Error in Probability
« Reply #20 on: April 27, 2015, 08:54:32 PM »
Quote
Again, I have to stress that the error made by scepticus and many others, is that you cannot assign a probability of a complete series to the next single outcome, or part of that series. What's past is gone, and probability does not apply, certainty does. -Slacker

Slacker,

Above is the biggest problem confronting many gambler's.  The logic required to comprehend it is just out of reach for most of them.  No matter how many different ways you explain it, they can't grasp it.  There's a level of intellect that is missing that prevents them from ever fully understanding it, and accepting it.  Try as you might, you will never convince most of them.

It's often been said by public officials that taxes on gambling and cigarettes is a tax on the poor and ignorant.  They're not entirely wrong.   The gambler's fallacy is part of that proof.
like I said a million times this problem
Again the expert of repeating the same thing over a million times, without substantiation. The only attempt to substantiate is to parallel  unrelated situations with a humorous twist.
Contradicting yourself in the process.
Biased and defective roulettes do not produce unbiased and independent  results. When it comes to your methods some roulettes are terribly defective. When it comes to systems they are the poster boy of mechanical perfection. Defects and bias are mutually exclusive with independence of spins.
Sorry. Just the facts. Rather than gathering members to agree with you, prove your points. Then offer in detail your own winning methods for others to comment on.
Prove what you say, rather than referring to textbooks, when it's a well known fact short runs do not necessarily comply with probability. Or tell us what the long run is, so we can have something to work with.
This is what Slacker said:  You can indeed make a system out of the knowledge that there is at least one repeat with probability 56% in the last 8 spins, but in order for the probability to remain valid, you have to place your bets from spin 1, not after spin 7

I guess  you are asking him to contradict himself.
Or tell the math experts that the probability  of series is a myth.
Looking at the picture one can easily conclude that the issue is made up of 2 questions. Not one question. It further implies that a compromise has to be made.
« Last Edit: April 27, 2015, 09:07:17 PM by palestis »

#### Real

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##### Re: A Common Error in Probability
« Reply #21 on: April 27, 2015, 10:51:03 PM »
I'm sorry Palestis,

It's unlikely that you will ever comprehend the reasons written above.  Furthermore, you keep changing the arguments in a way that doesn't even make sense to other readers.

My suggestion is that you keep your bets low, and increase the number of virtual bets that you place.  This will slow the rate at which you inevitably lose your bankroll.

Cheers,
Real
« Last Edit: April 28, 2015, 07:34:55 AM by kav »

#### Bayes

##### Re: A Common Error in Probability
« Reply #22 on: April 28, 2015, 08:32:28 AM »
@ Real,

You may be right, but as palestis says, this is very important so I'm going to continue trying. Besides, I find it an interesting challenge. I may not be able to convince palestis, but he's not the only one reading this thread.

palestis, I'm not sure what point you're trying to make because you've repeated some of the arguments I made in previous posts, for example about being able to bet only one spin at a time. I'm not sure where you and I disagree, so can you tell me what precisely you think is wrong with the argument in my first post?

Are you saying that scepticus is correct: that the chance of getting a repeat (a win) on the last spin of the series, given that there have been no previous repeats, really is 56% and not 19%?

Please answer yes or no without going off on a tangent. The issue is really very simple, and I may have in fact muddied the waters by using the idea of series versus single events. It actually comes down to the question of whether spins are independent or not.

Fortunately, we don't have to argue endlessly about any of this, because it would be quite easy to test palestis' theory on some spins.
• The so called NULL hypothesis is that there is no difference between waiting for virtual losses and just betting randomly from the first spin. i.e., Waiting for losses and not waiting will, on average, result in the next win coming just as quickly in both cases.
• The ALTERNATIVE hypothesis is that there IS a difference, so that you are likely to get at least one winner within a shorter number of spins than would be the case if you had NOT waited for the "virtual losses".
However, I'm not so naive that I think palestis will change his mind even with empirical evidence. The trouble is that if you don't understand the principle, then you might be inclined to think that the result only applies to THAT particular system or scenario under test, but what about the infinite number of other possible roulette systems?
I think this is where you're correct, Real. Some people won't ever be able to abstract from the particular details of a system and see that it's built on the same fallacy.

#### palestis

##### Re: A Common Error in Probability
« Reply #23 on: April 28, 2015, 08:40:17 AM »
I'm sorry Palestis,

It's unlikely that you will ever comprehend the reasons written above.  Furthermore, you keep changing the arguments in a way that doesn't even make sense to other readers.

My suggestion is that you keep your bets low, and increase the number of virtual bets that you place.  This will slow the rate at which you inevitably lose your bankroll.

Cheers,
Real
For your info, I don't know what losing is (never mind losing the entire bankroll). The worst thing that has happened is come back from the casino with just \$20 over my bankroll. I haven't experience a losing session yet, because I simply don't allow it to happen. Patience has been proven to be the player's greater asset. Nowhere in my play,  I find your theories to be valid. So I don't know what you are talking about. Your advice  probably better serves a new gambler.

#### palestis

##### Re: A Common Error in Probability
« Reply #24 on: April 28, 2015, 10:14:39 PM »
@ Real,

You may be right, but as palestis says, this is very important so I'm going to continue trying. Besides, I find it an interesting challenge. I may not be able to convince palestis, but he's not the only one reading this thread.

palestis, I'm not sure what point you're trying to make because you've repeated some of the arguments I made in previous posts, for example about being able to bet only one spin at a time. I'm not sure where you and I disagree, so can you tell me what precisely you think is wrong with the argument in my first post?

Are you saying that scepticus is correct: that the chance of getting a repeat (a win) on the last spin of the series, given that there have been no previous repeats, really is 56% and not 19%?

Please answer yes or no without going off on a tangent. The issue is really very simple, and I may have in fact muddied the waters by using the idea of series versus single events. It actually comes down to the question of whether spins are independent or not.
The way you are asking the question has nothing to do with the probability of series. You set the condition GIVEN THAT THERE WERE NO PREVIOUS REPEATS. This is simply asking what the next spin will be. In that case it's 19%. Because  YOU SET A CONDITION.
The probability of series has no conditions. Just a stipulation to win once out of 8 tries. Provided you place a bet (virtual or real and  regardless of \$ amount ) in all 8 tries. In that case is 56% till the end of the series. it can happen with the first spin or it can happen with the 8th spin, or it might not happen at all.
If you meant no repeat in the previous 7 spins (provided that you have placed all 7 bets), then there is no answer. What's the importance of the 8th spin anyway, when you had 7 more spins to play?
Probability of series looks at the whole picture, not parts of the picture.
The biggest fallacy of all is to dwell on probabilities, as a means to win the roulette.
THE PLAYER PLAYS IN THE SHORT RUN. And in the short run the rules of probability do not apply.
That's y we have forums. To get information on how to exploit  instabilities in the short run and win. . If you think like real, then there should be no need for forums, and no need to play roulette at all. I don't see any FUN in playing a game where losing money is a certainty. I don't even like roulette. The only part I like is that you can create money out of nothing, without manual labor but  one's brains. Players who are guided by probability alone, are doing themselves a disservice.
It is the short run we are dealing with, and experience supersedes probability and math.
The goal in playing roulette is not to validate probability theory. it is to leave the casino with more money that you went in with.. If someone doesn't know how, then this is a good place  to ask for help.
Comments  that I am ignorant of probability and math are redundant.  It's a replacement for valid arguments and lack of proof to the contrary. I've been playing  roulette too  long. And I know exactly where I'm standing. Theories of the "real" type are more suitable for a new kid on the block.
« Last Edit: April 29, 2015, 12:50:28 AM by palestis »

#### Bayes

##### Re: A Common Error in Probability
« Reply #25 on: April 29, 2015, 12:25:18 PM »
palestis,

I think you misunderstand me, I'm not in the "Real" camp regarding math. I do have a lot of respect for the guy because he really is an expert in advantage play,  but as far as he's concerned the mathematical expectation tells you EVERYTHING you need to know about the "game".  He takes the view that the random game is unbeatable, so you have to target the physical device, environmental conditions, dealer "signature" and so on. It's not that he's seriously tried the other way and found it wanting, it's just that he dismisses it as a fallacy, because the mathematical expectation of the "ideal" game says that you will inevitably lose "in the long run" owing to the unfair payout, no matter what fancy systems  or MM you use.

I know he's mistaken, because I and others do consistently make a profit without using physics. Mathematical expectation is not the ONLY thing that determines whether you win or lose, and I'm not talking about the stuff that gambler's bang on about as being crucial, like "quitting while ahead" (which is meaningless unless you plan to never play again) or self-discipline, which is necessary of course, but not sufficient.

There is a kind of "toolbox" of techniques which I use in order to keep the deviations within reasonable limits. and once you can do that, MM takes care of the rest. One of those techniques is to exploit anomalies in the random stream, just as you do. I wouldn't be surprised if we play in a very similar way.

In a nutshell, I attack an anomaly for one or two spins, betting that it will end. If it doesn't I bet that it will continue, then when it does end I switch again and bet that it won't immediately repeat. I have one eye on my W/L results and switch to a different target if things aren't going well. I never "chase" a target with steep progressions, and I always follow a pattern as long as it continues to win. It's that simple.

I have written various programs which track spins and reveal patterns and anomalies, extreme events etc. There are countless opportunities occurring all the time, and I never wait for "triggers", but bet every spin.

I've attached a screenshot of one sequence of my morning's play. After the two long losing sequences (marked with black circles) I started betting for a return to some kind of normality. An event like this (6 wins out of the last 34 spins) is obviously an extreme event and cannot continue. Even if it HAD continued for a bit longer it wouldn't have been a disaster because I would just have kept my bets low until there was some indication of leveling off.

I strongly disagree about your assessment of probability as being useless, or worse, as an aid to playing roulette.

Quote
THE PLAYER PLAYS IN THE SHORT RUN. And in the short run the rules of probability do not apply.

In the first place, there is no definite line of demarcation between the "short run" and the "long run"; it's a matter of degree. And isn't the long run just a succession of short runs? In statistical jargon, the "sample" MUST resemble the "population" in some degree in terms of the relative frequency of events.

As I said in my previous post, the probability in the long run of an event (which is what you say IS valid, but useless for the short run - namely, playing roulette), is the BEST GUESS in the short run. If there was not a tendency for a series of single outcomes or events to converge towards their long run probability, then the long run probability would be something OTHER than what it is. That's just common sense.

And you seem to be ignoring the point I made earlier about Ashley Revell. Does probability really have NOTHING to say about what may be the best strategy to use for someone who wants to make his bank last as long as possible during an evening in the casino? This is surely the "short run", but according to you, it makes no difference whether he bets his entire bank on number 17 in one spin or splits it into 100 pieces and plays one piece at a time on red!

Then there's the issue of the house edge. Some games have a much higher house edge than others, does it really make no difference what game you play, since probability is irrelevant in the short run? obviously not.

Quote
That's y we have forums. To get information on how to exploit  instabilities in the short run and win.

And probability theory is one way of getting that information. You don't have to use it, but it's there to be used, and it can often suggest different lines of attack.

The problem is that guys like Real encourage the view that math and probability is just a stick with which to beat system players over the head with. "The math says you can't win". So end of story. It is so much more than that. It's also worth pointing out that the definition of probability as a "long run relative frequency" is just one interpretation, which is not always useful. See the Wikipedia article:

http://en.wikipedia.org/wiki/Probability_interpretations

It's true that the mathematical rules or laws of probability are the same in all interpretations, but these rules have more to do with logic than math; they are just a way of keeping you from contradicting yourself when reasoning with probabilities.
« Last Edit: April 29, 2015, 12:59:15 PM by Slacker »

#### Real

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##### Re: A Common Error in Probability
« Reply #26 on: April 29, 2015, 01:57:25 PM »
Quote
I know he's mistaken, because I and others do consistently make a profit without using physics. Mathematical expectation is not the ONLY thing that determines whether you win or lose, and I'm not talking about the stuff that gambler's bang on about as being crucial, like "quitting while ahead" (which is meaningless unless you plan to never play again) or self-discipline, which is necessary of course, but not sufficient.
Sorry Slacker,
But  I suspect that you're simply experience the waves of variance in a diminished number of trials.  But if you're having fun with it, then have at it.
Quote

There is a kind of "toolbox" of techniques which I use in order to keep the deviations within reasonable limits. and once you can do that, MM takes care of the rest. One of those techniques is to exploit anomalies in the random stream, just as you do. I wouldn't be surprised if we play in a very similar way
.-Slacker
"No betting system can convert a subfair game into a profitable enterprise... "— Probability and Measure(second edition, page 94) by Patrick Billingsley

"The number of ‘guaranteed’ betting systems, the proliferation of myths and fallacies concerning such systems, and the countless people believing, propagating, venerating, protecting, and swearing by such systems are legion. Betting systems constitute one of the oldest delusions of gambling history. Betting systems votaries are spiritually akin to the proponents of perpetual motion machines, butting their heads against the second law of thermodynamics." — The Theory of Gambling and Statistical Logic (page 53) by Richard A. Epstein
« Last Edit: April 29, 2015, 10:14:52 PM by kav »

#### Bayes

##### Re: A Common Error in Probability
« Reply #27 on: April 29, 2015, 02:20:24 PM »
Real,

You're so predictable.

Quote
But  I suspect that you're simply experience the waves of variance in a diminished number of trials.

I've placed well over 100,000 bets each year for the last 3 years or so. Variance? I don't think so.

There ARE those who win consistently without using advantage play. You can choose to believe it or not. That doesn't mean I subscribe to the gambler's fallacy or any other fallacies.

#### Real

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##### Re: A Common Error in Probability
« Reply #28 on: April 29, 2015, 02:21:42 PM »
Slacker,

How many units were won over the 100k bets?
A live wheel or an RNG wheel online in fun mode?
« Last Edit: April 29, 2015, 03:41:55 PM by kav »

#### palestis

##### Re: A Common Error in Probability
« Reply #29 on: April 29, 2015, 08:44:17 PM »
palestis,

I know he's mistaken, because I and others do consistently make a profit without using physics. Mathematical expectation is not the ONLY thing that determines whether you win or lose, and I'm not talking about the stuff that gambler's bang on about as being crucial, like "quitting while ahead" (which is meaningless unless you plan to never play again) or self-discipline, which is necessary of course, but not sufficient.

There is a kind of "toolbox" of techniques which I use in order to keep the deviations within reasonable limits. and once you can do that, MM takes care of the rest. One of those techniques is to exploit anomalies in the random stream, just as you do. I wouldn't be surprised if we play in a very similar way.
Well there you go. You covered a lot in your post and I'm certainly impressed.
The bottom line is that you win consistently. And it's not by physics or device exploitation.
According to Real, NOBODY can win consistently,  unless you take the physics route. If you played that many spins and you are ahead of the game it's definitely not a coincidence. I doubt if Real will believe you, but I have no reason to doubt you because I'm at the same level. And I know people who win consistently. By the way I too play in a similar way. I look for trends and short  term anomalies. The secret is to limit the bets to a minimum, whether following an anomaly or betting that it will stop. That way you can never lose your shirt, especially with aggressive progression if the exception happens. If it doesn't work in one cycle, it is highly unlikely that it won't work in the next cycle of anomalies. And with a good MM system you can recover and also you can neutralize the effects of the HE
When we talk about probabilities, it's not always about "what is due to happen". I'm sure you have your own probability figures regarding the chances of an anomaly being continued for one more time or the probability to stop after a certain point. But I can't let probability and the unfair payout prevent me from winning, as there are opportunities emerging all the time that can be taken advantage of.
Probability is only a part of the game. there are other things involved as long as you know how to spot opportunities. That is y I don't spend much time philosophizing about probability. My focus is to identify opportunities. Whatever probability is behind it, I don't care. It automatically kicks in because all these opportunities fall into identifiable groups. Once you have established a plan of action there is no need to consult with probabilities. They are built  in the plan of action.
But anyway, after saying that you have been winning consistently, you obviously admit that there are ways to win roulette with systems, So the argument is settled.
Because from your initial posting, you came across as a non believer of systems. And as your reasoning seemed to be the probability disadvantage.
Now the question is, can you convince another member in this forum?
Because he's already started to ask you questions about your play. If it was live wheel or RNG or play for fun. Obviously he doesn't believe that you have consistent winnings, even if he initially agreed with  your reasoning.
Maybe you should post one of your systems regarding anomalies or trends so we can analyze it.
That would be for more productive, instead of dwelling on probability theories.
As far as physics and VB and bias and defects, in the pic below the expert author describes his encounter with casino stuff, after watching and clocking the wheel.
Not after playing and winning, but simply by watching.