### Author Topic: Do the odds of an event change as the number of trials increase?  (Read 10001 times)

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#### Avalon

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##### Do the odds of an event change as the number of trials increase?
« on: May 07, 2016, 09:28:09 AM »
This is something which I long suspected to be true, but never found any proof of it.
Lets keep out any mental biases of house edge, unbalanced wheels, etc and take a series of coin tosses. Similar to red/black, odds/evens.
If the last 10 tosses have been tails, does it mean that heads is "overdue"?

More importantly, has anyone actually betted on an overdue event and what were the results? I suspect that many have already tried it, so where are the results for and against?

#### Trilobite

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##### Re: Do the odds of an event change as the number of trials increase?
« Reply #1 on: May 07, 2016, 10:05:39 AM »

If the last 10 tosses have been tails, does it mean that heads is "overdue"?

No it does not, because the 10 tails tosses are past events leaving only the next toss to evaluate, which you must evaluate as a 50/50 proposition.

----------------------

I have another loosely related question.

Let’s say I bet a particular way on 1 dozen.
The long term chance of me making a profit is -2.7%

Let’s say I bet the particular way on 1 dozen and make a profit over 50,000 placed bets.

What then is the chance of me making a profit on the next 50,000 placed bets?

Let’s say I also make a profit on the 2nd run of 50,000 placed bets.

What then is the chance of me making a profit on the next 50,000 placed bets?
« Last Edit: May 07, 2016, 10:21:48 AM by Trilobite »

#### scepticus

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##### Re: Do the odds of an event change as the number of trials increase?
« Reply #2 on: May 07, 2016, 10:59:20 AM »

If the last 10 tosses have been tails, does it mean that heads is "overdue"?

No it does not, because the 10 tails tosses are past events leaving only the next toss to evaluate, which you must evaluate as a 50/50 proposition.

----------------------

I have another loosely related question.

Let’s say I bet a particular way on 1 dozen.
The long term chance of me making a profit is -2.7%

Let’s say I bet the particular way on 1 dozen and make a profit over 50,000 placed bets.

What then is the chance of me making a profit on the next 50,000 placed bets?

Let’s say I also make a profit on the 2nd run of 50,000 placed bets.

What then is the chance of me making a profit on the next 50,000 placed bets?

If past spins have no effect on future spins why do maths geeks claim that they can prove we must lose when what they provide is a lot of "Past Spins" ?
Once they  start  their Long Run doesn't each and every spin thereafter become a " Past Spin" ?
If each and every spin is independent doesn't this mean that we should concentrate on the " Now " ?And leave the future to the future.
So far as I am concerned an unpredictable future is an unpredictable future.

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#### Avalon

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##### Re: Do the odds of an event change as the number of trials increase?
« Reply #3 on: May 07, 2016, 11:09:58 AM »

If the last 10 tosses have been tails, does it mean that heads is "overdue"?
No it does not, because the 10 tails tosses are past events leaving only the next toss to evaluate, which you must evaluate as a 50/50 proposition.----------------------
Your reply is in line with the gamblers fallacy which evaluates each event as independent and unrelated to what happened before.

The main question was this, where are the results to prove or disprove the theory?
It shouldn't be that hard to run a small program to evaluate the result of betting on heads after n tails have passed.

#### Sputnik

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##### Re: Do the odds of an event change as the number of trials increase?
« Reply #4 on: May 07, 2016, 12:26:14 PM »
I never forget this quote from WIKI:

"Regression toward the mean simply says that, following an extreme random event, the next random event is likely to be less extreme. In no sense does the future event "compensate for" or "even out" the previous event, though this is assumed in the gambler's fallacy (and variant law of averages). Similarly, the law of large numbers states that in the long term, the average will tend towards the expected value, but makes no statement about individual trials. For example, following a run of 10 heads on a flip of a fair coin (a rare, extreme event), regression to the mean states that the next run of heads will likely be less than 10, while the law of large numbers states that in the long term, this event will likely average out, and the average fraction of heads will tend to 1/2. By contrast, the gambler's fallacy incorrectly assumes that the coin is now "due" for a run of tails, to balance out."

#### Avalon

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##### Re: Do the odds of an event change as the number of trials increase?
« Reply #5 on: May 07, 2016, 12:54:14 PM »
By contrast, the gambler's fallacy incorrectly assumes that the coin is now "due" for a run of tails, to balance out."
Actually, the gamblers fallacy says that past events have no bearing on the future, which is in direct opposition to reversion to the mean. I'm not a math whiz, but reversion to the mean is an accepted technique in statistics.
There was a post from kav in another thread which summed it up nicely. Trying to find it.

Still doesn't answer my question re actual results.
It's not very difficult to write a small computer program to read a set of spins ........ and bet on black after 5 consecutive reds have passed....... on 1000 bets, what are the results?
I would expect that many would have already done it, why aren't the results being made public?

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#### Trilobite

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##### Re: Do the odds of an event change as the number of trials increase?
« Reply #6 on: May 07, 2016, 09:22:53 PM »

It's not very difficult to write a small computer program to read a set of spins ........ and bet on black after 5 consecutive reds have passed....... on 1000 bets, what are the results?
I would expect that many would have already done it, why aren't the results being made public?

It's all been done before and the results were always negative. That's because the "5 reds" event doesn't change the odds, and doesn't improve the bet selection.

#### scepticus

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##### Re: Do the odds of an event change as the number of trials increase?
« Reply #7 on: May 08, 2016, 12:05:11 AM »

It's not very difficult to write a small computer program to read a set of spins ........ and bet on black after 5 consecutive reds have passed....... on 1000 bets, what are the results?
I would expect that many would have already done it, why aren't the results being made public?

It's all been done before and the results were always negative. That's because the "5 reds" event doesn't change the odds, and doesn't improve the bet selection.

True Trilo True !
This is because if you factor in a negative the answer will always be negative. This is why I think this kind of approach is futile. Though many disagree .

#### Sheridan44

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##### Re: Do the odds of an event change as the number of trials increase?
« Reply #8 on: May 08, 2016, 02:34:50 AM »
I tend to agree. Testing any system for a kazillion spins is always going to produce the same result (downward). I've been guilty of this myself, spending hours on a system, then putting it through an absurd test of thousands of spins - and feeling so deflated at the results from all the time and emotion I put into it. What the hell did I expect? ...I have to ask myself. I was testing it based on infinity....well - I'll never be playing it infinitely. I don't have that kind of stamina (or bankroll). I suspect a test of a complete cycle of the wheel ( 37 numbers X 37 Spins ) = 1369 Spins ( 1444 for the american wheel ) would be more than plenty enough as related to realistic play.

I think a more viable test would be of system resiliency...... how well it holds up before it takes its inevitable plunge.

From this, one could craft optimal progressions / regressions, betting selections, opportunistic timing.... win goals / loss limits..etc.

Another factor is the velocity of betting. Betting spin after spin is like being on a runaway locomotive racing towards the cliff of quick variability moves and house edge. You are more liable to lose your cool, abandoning your plans (if one had any) betting crazier, in a panic / desperation mode. A quick entrance / quick exit... might work better in instances...but saying it and doing it are two different things. It can be very hard to pry yourself away when being caught up in the action. We should have some circuit breakers in place. Slowing the velocity gives more opportunities to think clearly - and it creates time to develop and implement sounder strategies that are more likely to produce positive results on balance.

Strategic Planning / Tactical Planning

" \$\$\$ It's not how much you win, it's how little you lose \$\$\$"
« Last Edit: May 08, 2016, 03:53:19 AM by Sheridan44 »

#### dobbelsteen

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##### Re: Do the odds of an event change as the number of trials increase?
« Reply #9 on: May 08, 2016, 03:08:20 PM »
The profit percentage start with + 100% or -100% and decrease according the number of  spins to -2,7%.
In this way the result of an event depends on the length of the sample.
50 000 bets is that the same as 50 000 spins?.
The outcome of a spin can not compare with the result ofa session or sample.

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#### Harryj

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##### Re: Do the odds of an event change as the number of trials increase?
« Reply #10 on: May 11, 2016, 03:51:25 PM »
Avalon,
After seeing 10 blacks in a row the chance that the 11th will be black is 50/50. The chance that you will see 11 blacks in a row is 2047/1 ! The reason is that the 10 blacks are in thee past, and cannot in any way effect future spins.

The real question is. Having made a bet that the next 11 spins WILL NOT BE ALL BLACK do the odds  reduce as a number of blacks appear ? After all, even if there are 10 blacks the 11th could still win the whole bet.

Harry

#### palestis

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##### Re: Do the odds of an event change as the number of trials increase?
« Reply #11 on: May 12, 2016, 01:39:44 AM »
This is something which I long suspected to be true, but never found any proof of it.
Lets keep out any mental biases of house edge, unbalanced wheels, etc and take a series of coin tosses. Similar to red/black, odds/evens.
If the last 10 tosses have been tails, does it mean that heads is "overdue"?

More importantly, has anyone actually betted on an overdue event and what were the results? I suspect that many have already tried it, so where are the results for and against?
In my opinion past results influence future results as long as  you DEFINE WHAT FUTURE RESULTS are. For my playing purposes I define future results ONE AND ONLY ONE SUCCESSFUL WAGER in a very small  range of trials that will follow a rare event. Beyond that, there is no future results for me. Mission is accomplished.
Like a head after 10 consecutive tails in the next 3 tosses. It is the expectation that more positive results will occur that gives credit to the gambler's fallacy.
In the long run everything comes to equilibrium (and nobody can dispute that). In the short run don't expect equilibrium after a great imbalance. But you sure as hell can expect one successful result in a small range of bets.
In effect short runs are mini long runs, where one expected results can be realized, provided you don't aim to reach the equilibrium that occurs in long runs.
As long as you aim for one hit after a great imbalance, this single future result is greatly affected by past results. All tests done over the years lead to this conclusion.
« Last Edit: May 12, 2016, 01:45:25 AM by palestis »

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#### Sheridan44

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##### Re: Do the odds of an event change as the number of trials increase?
« Reply #12 on: May 12, 2016, 02:06:53 AM »
Exactly....... if coins have "no memory" one should be able to toss heads 10 times in a row quite frequently and more often.

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#### dobbelsteen

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##### Re: Do the odds of an event change as the number of trials increase?
« Reply #13 on: May 12, 2016, 08:33:50 AM »
Every experience player knows that nobody can predict the outcome of a spin.The hitchance of all chances of the next spin are well-known.
The real player is only interested in the outcome of the next spins.
When I wager SSB , I wager not on the next spin but on the 10 number event. My chance on a hit is nearly 100%. The profit % varies between 0.5% and 25%. See the challence.

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#### Jesper

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##### Re: Do the odds of an event change as the number of trials increase?
« Reply #14 on: May 13, 2016, 12:44:24 PM »
The chance for a number  to hit is on a fair wheel same for all, but if we miss a number for 600 spins, we can in the very much cases expect it in a few hundred. The most extreme is possible, but when will we see it?

1001 is the maximum times of a sleeping number I have seen, and I do not think it will be seen again by me.

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