OT: OzLotto Randomness

[David L. Jones]

OT thought for the day...
Bought my ticket for tomorrows $90M draw and was told they are the winning
numbers, so I'm sitting pretty, but I digress...
Ever since I can remember I've always noticed something with the "random"
machine picked numbers.
The numbers always seemed quite spread out, no matter how many times I've
played the random pick over the years. Occasional clumps within, but always
appers to be one number at either end etc
I would have expected sooner or later to hit upon some numbers that were all
grouped at one end or the other, or in the middle etc, but I can't ever
recall that happening.
Anyone else noticed that?
Just wondering if it's truly random, or whether it uses some other algorithm
designed to "appear more random" to the average punter who might be a bit
miffed if the machine spitted out all numbers under 10 for example?
Any statisticians in the house that can calculate the odds of all 7 numbers
being within a window of say 15 in a random pick?

Dave.
--
================================================
Check out my Electronics Engineering Video Blog & Podcast:
http://www.alternatezone.com/eevblog/

 

[Phil Allison]

"David L. Jerkoff"

OT thought for the day...
Bought my ticket for tomorrows $90M draw and was told they are the winning
numbers, so I'm sitting pretty, but I digress...
Ever since I can remember I've always noticed something with the "random"
machine picked numbers.
The numbers always seemed quite spread out, no matter how many times I've
played the random pick over the years. Occasional clumps within, but
always appers to be one number at either end etc
I would have expected sooner or later to hit upon some numbers that were
all grouped at one end or the other, or in the middle etc, but I can't
ever recall that happening.
Anyone else noticed that?
Just wondering if it's truly random, or whether it uses some other
algorithm designed to "appear more random" to the average punter who might
be a bit miffed if the machine spitted out all numbers under 10 for
example?
Any statisticians in the house that can calculate the odds of all 7
numbers being within a window of say 15 in a random pick?

** Forget all that probability stuff from your HSC Maths ??

OK :

Imagin the seven balls being withdrawn one at a time out of 45 numbered
balls.

Ball 1 can be any number.

Ball 2 must be within a group of 15 numbers of which ball 1 is a member.

So, there are 14 candidates for ball 2 in the group.

The chance of picking one of them is 14/44 or 0.318

Similar arguement goes for each of the remaining 5 balls.

So P = 14/44 x 13/43 x 12/42 x 11/41 x 10/40 x 9/39

therefore P = 0.0004254

or 1 chance in 2350

With one draw a week, it means around 45 years until you expect to see such
a close grouping.



...... Phil

 

[Sylvia Else]

Phil Allison wrote:

"David L. Jerkoff"
OT thought for the day...
Bought my ticket for tomorrows $90M draw and was told they are the winning
numbers, so I'm sitting pretty, but I digress...
Ever since I can remember I've always noticed something with the "random"
machine picked numbers.
The numbers always seemed quite spread out, no matter how many times I've
played the random pick over the years. Occasional clumps within, but
always appers to be one number at either end etc
I would have expected sooner or later to hit upon some numbers that were
all grouped at one end or the other, or in the middle etc, but I can't
ever recall that happening.
Anyone else noticed that?
Just wondering if it's truly random, or whether it uses some other
algorithm designed to "appear more random" to the average punter who might
be a bit miffed if the machine spitted out all numbers under 10 for
example?
Any statisticians in the house that can calculate the odds of all 7
numbers being within a window of say 15 in a random pick?


** Forget all that probability stuff from your HSC Maths ??

OK :

Imagin the seven balls being withdrawn one at a time out of 45 numbered
balls.

Ball 1 can be any number.

Ball 2 must be within a group of 15 numbers of which ball 1 is a member.

So, there are 14 candidates for ball 2 in the group.

No, there are up to 28 candidates - 14 either side of the first ball -
except that there are fewer if the first ball is less than 15, or more
than 31.

After the second ball has been chosen, the number of remaining
candidates is determined by how far apart the first ball and second ball
are; if the second ball is at the other end of a 15 grouping, then there
are only 13 candidates remaining. On the other hand, if the second ball
is adjacent to the first, then there are 26 candidates remaining - 13
either side of the pair, but again subject to end effects.

So this probability calculation is nothing like as simple as you're
suggesting.

Sylvia.

 

[Sylvia Else]

Phil Allison wrote:

"Sylvia Else"
Phil Allison wrote:
"David L. Jerkoff"
OT thought for the day...
Bought my ticket for tomorrows $90M draw and was told they are the
winning numbers, so I'm sitting pretty, but I digress...
Ever since I can remember I've always noticed something with the
"random" machine picked numbers.
The numbers always seemed quite spread out, no matter how many times
I've played the random pick over the years. Occasional clumps within,
but always appers to be one number at either end etc
I would have expected sooner or later to hit upon some numbers that were
all grouped at one end or the other, or in the middle etc, but I can't
ever recall that happening.
Anyone else noticed that?
Just wondering if it's truly random, or whether it uses some other
algorithm designed to "appear more random" to the average punter who
might be a bit miffed if the machine spitted out all numbers under 10
for example?
Any statisticians in the house that can calculate the odds of all 7
numbers being within a window of say 15 in a random pick?

** Forget all that probability stuff from your HSC Maths ??

OK :

Imagin the seven balls being withdrawn one at a time out of 45 numbered
balls.

Ball 1 can be any number.

Ball 2 must be within a group of 15 numbers of which ball 1 is a member.

So, there are 14 candidates for ball 2 in the group.
No, there are up to 28 candidates - 14 either side of the first ball -
except that there are fewer if the first ball is less than 15, or more
than 31.

After the second ball has been chosen, the number of remaining candidates
is determined by how far apart the first ball and second ball are; if the
second ball is at the other end of a 15 grouping, then there are only 13
candidates remaining. On the other hand, if the second ball is adjacent to
the first, then there are 26 candidates remaining - 13 either side of the
pair, but again subject to end effects.

So this probability calculation is nothing like as simple as you're
suggesting.


** My calc was a bit simplified.

Which is OK if you say so, and provide an argument that shows that it
represents either an upper or a lower limit on the probability. As it
stands, it's just a calculation of a probability for a different problem
with no indiciation of how the result relates to the question asked.

But there is a group of 15 consecutive numbers at the end of the picking and
the 5 balls chosen are all members of that group.

Do it your way and tell us the answer.

Bet you have to write a program for it.

That seems the obvious approach anyway. The figure I get is exactly 15
in 7052, or about 1 in 470.

For one draw a week, that's once every 9 years.

Sylvia.

 

[Franc Zabkar]

On Mon, 29 Jun 2009 13:14:40 +1000, "David L. Jones"
<altzone@gmail.com> put finger to keyboard and composed:

OT thought for the day...
Bought my ticket for tomorrows $90M draw and was told they are the winning
numbers, so I'm sitting pretty, but I digress...
Ever since I can remember I've always noticed something with the "random"
machine picked numbers.
The numbers always seemed quite spread out, no matter how many times I've
played the random pick over the years. Occasional clumps within, but always
appers to be one number at either end etc
I would have expected sooner or later to hit upon some numbers that were all
grouped at one end or the other, or in the middle etc, but I can't ever
recall that happening.
Anyone else noticed that?
Just wondering if it's truly random, or whether it uses some other algorithm
designed to "appear more random" to the average punter who might be a bit
miffed if the machine spitted out all numbers under 10 for example?
Any statisticians in the house that can calculate the odds of all 7 numbers
being within a window of say 15 in a random pick?

Dave.

You first need to count the total number of ways that 7 balls can be
arranged in a group of 15 where there is a ball at each endpoint.

Ball 1 - 5 balls in 13 positions - Ball 15
Balll 2 - 5 balls in 13 positions - Ball 16
....................................................
Ball 31 - 5 balls in 13 positions - Ball 45

Then you need to do the same for groups of 14, 13, 12, ... 7.

The total number of possible "clumps" is ...

(31 x 13C5) + (32 x 12C5) + (33 x 11C5) + ... + (39 x 5C5)

The total number of ways you can select 7 balls from 45 is 45C7.

So the chance of a clump of 15 or less is ...

(31 x 13! / 8! + 32 x 12! / 7! + 33 x 11! / 6! + 34 x 10! / 5! + 35 x
9! / 4! + 36 x 8! / 3! + 37 x 7! / 2! + 38 x 6! / 1! + 39 x 5! / 0!) x
42 / (45 x 44 x 43 x 42 x 41 x 40 x 39)

http://www.google.com/search?hl=en&client=opera&rls=en&num=25&newwindow=1&q=%2831+x+13%21+%2F+8%21+%2B+32+x+12%21+%2F+7%21+%2B+33+x+11%21+%2F+6%21+%2B+34+x+10%21+%2F+5%21+%2B+35+x+9%21+%2F+4%21+%2B+36+x+8%21+%2F+3%21+%2B+37+x+7%21+%2F+2%21+%2B+38+x+6%21+%2F+1%21+%2B+39+x+5%21+%2F+0%21%29+x+42+%2F+%2845+x+44+x+43+x+42+x+41+x+40+x+39%29&btnG=Search

http://preview.tinyurl.com/n6xgw9

= 0.00212705615

= 0.2%

= 1 in 500

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

 

[Sylvia Else]

Phil Allison wrote:

Bet you have to write a program for it.

I wrote one. However...

There are:

39 ways in which the first and last balls extend over 7 numbers.

38 ways in which the first and last balls extend over 8 numbers. The
middle 5 balls can be laid out in 6!/5!/1! different ways.

37 ways in which the first and last balls extend over 9 numbers. The
middle 5 balls can be laid out in 7!/5!/2! different ways.

36 ways in which the first and last balls extend over 10 numbers. The
middle 5 balls can be laid out 8!/5!/3! different ways.

And so on until

31 ways in which the first and last balls extend over 15 numbers. The
middle 5 balls can be laid out 13!/5!/8! different ways.

So the total number of ways of laying out 7 balls such that they extend
no more than 15 numbers is

(39 + 38 * 6!/1! + 37 * 7!/2! + 36 * 8!/3! .... + 31 * 13!/8!) / 5!

I can't see any way of simplifying it, but it comes to 96525.

The possible ways of laying out 7 balls in 45 positions is 45379620, so
the odds are 1 in 45379620 / 96525, which is indeed 15 in 7052 or about
1 in 470.

Sylvia.

 

[David L. Jones]

Franc Zabkar wrote:

On Mon, 29 Jun 2009 13:14:40 +1000, "David L. Jones"
altzone@gmail.com> put finger to keyboard and composed:

OT thought for the day...
Bought my ticket for tomorrows $90M draw and was told they are the
winning numbers, so I'm sitting pretty, but I digress...
Ever since I can remember I've always noticed something with the
"random" machine picked numbers.
The numbers always seemed quite spread out, no matter how many times
I've played the random pick over the years. Occasional clumps
within, but always appers to be one number at either end etc
I would have expected sooner or later to hit upon some numbers that
were all grouped at one end or the other, or in the middle etc, but
I can't ever recall that happening.
Anyone else noticed that?
Just wondering if it's truly random, or whether it uses some other
algorithm designed to "appear more random" to the average punter who
might be a bit miffed if the machine spitted out all numbers under
10 for example?
Any statisticians in the house that can calculate the odds of all 7
numbers being within a window of say 15 in a random pick?

Dave.

You first need to count the total number of ways that 7 balls can be
arranged in a group of 15 where there is a ball at each endpoint.

Ball 1 - 5 balls in 13 positions - Ball 15
Balll 2 - 5 balls in 13 positions - Ball 16
....................................................
Ball 31 - 5 balls in 13 positions - Ball 45

Then you need to do the same for groups of 14, 13, 12, ... 7.

The total number of possible "clumps" is ...

(31 x 13C5) + (32 x 12C5) + (33 x 11C5) + ... + (39 x 5C5)

The total number of ways you can select 7 balls from 45 is 45C7.

So the chance of a clump of 15 or less is ...

(31 x 13! / 8! + 32 x 12! / 7! + 33 x 11! / 6! + 34 x 10! / 5! + 35 x
9! / 4! + 36 x 8! / 3! + 37 x 7! / 2! + 38 x 6! / 1! + 39 x 5! / 0!) x
42 / (45 x 44 x 43 x 42 x 41 x 40 x 39)

http://www.google.com/search?hl=en&client=opera&rls=en&num=25&newwindow=1&q=%2831+x+13%21+%2F+8%21+%2B+32+x+12%21+%2F+7%21+%2B+33+x+11%21+%2F+6%21+%2B+34+x+10%21+%2F+5%21+%2B+35+x+9%21+%2F+4%21+%2B+36+x+8%21+%2F+3%21+%2B+37+x+7%21+%2F+2%21+%2B+38+x+6%21+%2F+1%21+%2B+39+x+5%21+%2F+0%21%29+x+42+%2F+%2845+x+44+x+43+x+42+x+41+x+40+x+39%29&btnG=Search

http://preview.tinyurl.com/n6xgw9

= 0.00212705615

= 0.2%

= 1 in 500

That's around about the figure I would have expected by gut feel.
So if you take say a dozen games a week (fairly common) you'd expect to see
something like that in under a year. Then there's Lotto and Powerball too.

Thanks
Dave.

--
---------------------------------------------
Check out my Electronics Engineering Video Blog & Podcast:
http://www.alternatezone.com/eevblog/

 

[Sylvia Else]

David L. Jones wrote:

That's around about the figure I would have expected by gut feel.
So if you take say a dozen games a week (fairly common) you'd expect to see
something like that in under a year. Then there's Lotto and Powerball too.

Thanks
Dave.

Is there more than one OzLotto draw a week?

Sylvia.

 

[Sylvia Else]

Sylvia Else wrote:

David L. Jones wrote:

That's around about the figure I would have expected by gut feel.
So if you take say a dozen games a week (fairly common) you'd expect
to see something like that in under a year. Then there's Lotto and
Powerball too.

Thanks
Dave.


Is there more than one OzLotto draw a week?

Sylvia.

Forget that, I misread your original posting.

Sylvia.

 

[Sylvia Else]

David L. Jones wrote:

Franc Zabkar wrote:
On Mon, 29 Jun 2009 13:14:40 +1000, "David L. Jones"
altzone@gmail.com> put finger to keyboard and composed:

OT thought for the day...
Bought my ticket for tomorrows $90M draw and was told they are the
winning numbers, so I'm sitting pretty, but I digress...
Ever since I can remember I've always noticed something with the
"random" machine picked numbers.
The numbers always seemed quite spread out, no matter how many times
I've played the random pick over the years. Occasional clumps
within, but always appers to be one number at either end etc
I would have expected sooner or later to hit upon some numbers that
were all grouped at one end or the other, or in the middle etc, but
I can't ever recall that happening.
Anyone else noticed that?
Just wondering if it's truly random, or whether it uses some other
algorithm designed to "appear more random" to the average punter who
might be a bit miffed if the machine spitted out all numbers under
10 for example?
Any statisticians in the house that can calculate the odds of all 7
numbers being within a window of say 15 in a random pick?

Dave.
You first need to count the total number of ways that 7 balls can be
arranged in a group of 15 where there is a ball at each endpoint.

Ball 1 - 5 balls in 13 positions - Ball 15
Balll 2 - 5 balls in 13 positions - Ball 16
....................................................
Ball 31 - 5 balls in 13 positions - Ball 45

Then you need to do the same for groups of 14, 13, 12, ... 7.

The total number of possible "clumps" is ...

(31 x 13C5) + (32 x 12C5) + (33 x 11C5) + ... + (39 x 5C5)

The total number of ways you can select 7 balls from 45 is 45C7.

So the chance of a clump of 15 or less is ...

(31 x 13! / 8! + 32 x 12! / 7! + 33 x 11! / 6! + 34 x 10! / 5! + 35 x
9! / 4! + 36 x 8! / 3! + 37 x 7! / 2! + 38 x 6! / 1! + 39 x 5! / 0!) x
42 / (45 x 44 x 43 x 42 x 41 x 40 x 39)

http://www.google.com/search?hl=en&client=opera&rls=en&num=25&newwindow=1&q=%2831+x+13%21+%2F+8%21+%2B+32+x+12%21+%2F+7%21+%2B+33+x+11%21+%2F+6%21+%2B+34+x+10%21+%2F+5%21+%2B+35+x+9%21+%2F+4%21+%2B+36+x+8%21+%2F+3%21+%2B+37+x+7%21+%2F+2%21+%2B+38+x+6%21+%2F+1%21+%2B+39+x+5%21+%2F+0%21%29+x+42+%2F+%2845+x+44+x+43+x+42+x+41+x+40+x+39%29&btnG=Search

http://preview.tinyurl.com/n6xgw9

= 0.00212705615

= 0.2%

= 1 in 500

That's around about the figure I would have expected by gut feel.
So if you take say a dozen games a week (fairly common) you'd expect to see
something like that in under a year. Then there's Lotto and Powerball too.

Thanks
Dave.

If you feel that that doesn't happen, then it suggests that using radom
machine picked numbers is a mistake, and you should instead be using
obviously non-random sequences.

The point being that it doesn't change your chance of winning, but does
change the chance that you'll have to share the jackpot with someone else.

Sylvia.

 

[terryc]

On Mon, 29 Jun 2009 13:14:40 +1000, David L. Jones wrote:

Just wondering if it's truly random,

Computer generated random numbers are NOT truly random.

I've noticed when playing a lot of online games with randomly generated
loot drop, that at certain times of the day, the drop is consistently
better. I suspect all games rank game drop from lowest to highest value
and the underlying bias moves up and down the scale according to a random
number affected by time of day. N.B. tested over 1,000 drops, so do not
waste your money on Lotto (different number generation mechanism).

 

[keithr]

terryc wrote:

On Mon, 29 Jun 2009 13:14:40 +1000, David L. Jones wrote:


Just wondering if it's truly random,

Computer generated random numbers are NOT truly random.

I've noticed when playing a lot of online games with randomly generated
loot drop, that at certain times of the day, the drop is consistently
better. I suspect all games rank game drop from lowest to highest value
and the underlying bias moves up and down the scale according to a random
number affected by time of day. N.B. tested over 1,000 drops, so do not
waste your money on Lotto (different number generation mechanism).

True, you cannot generate truly random numbers in software the pattern

will always repeat eventually. If you know the period of the algorithm
though, you can change the seed before anything repeats.

If you want true random, then you need to do it with hardware, the yanks
used radioactive decay to produce one time tapes for the hot line, and
the poms at least used to use gas discharge tubes for their premium bonds.

 

[The Real Andy]

On Mon, 29 Jun 2009 13:14:40 +1000, "David L. Jones"
<altzone@gmail.com> wrote:

OT thought for the day...
Bought my ticket for tomorrows $90M draw and was told they are the winning
numbers, so I'm sitting pretty, but I digress...
Ever since I can remember I've always noticed something with the "random"
machine picked numbers.
The numbers always seemed quite spread out, no matter how many times I've
played the random pick over the years. Occasional clumps within, but always
appers to be one number at either end etc
I would have expected sooner or later to hit upon some numbers that were all
grouped at one end or the other, or in the middle etc, but I can't ever
recall that happening.
Anyone else noticed that?
Just wondering if it's truly random, or whether it uses some other algorithm
designed to "appear more random" to the average punter who might be a bit
miffed if the machine spitted out all numbers under 10 for example?
Any statisticians in the house that can calculate the odds of all 7 numbers
being within a window of say 15 in a random pick?

Dave.

The chances of your numbers being consecutive are the same as them not
being consecutive.

The only reason you dont recall seing it is because you probably
haven't. I have spend a long time in the gaming and wagering industry
and I can assure you that I have seen numbers being drawn
consecutivley, from a hardware RNG and a ball cage.

 

[Sylvia Else]

The Real Andy wrote:

On Mon, 29 Jun 2009 13:14:40 +1000, "David L. Jones"
altzone@gmail.com> wrote:

OT thought for the day...
Bought my ticket for tomorrows $90M draw and was told they are the winning
numbers, so I'm sitting pretty, but I digress...
Ever since I can remember I've always noticed something with the "random"
machine picked numbers.
The numbers always seemed quite spread out, no matter how many times I've
played the random pick over the years. Occasional clumps within, but always
appers to be one number at either end etc
I would have expected sooner or later to hit upon some numbers that were all
grouped at one end or the other, or in the middle etc, but I can't ever
recall that happening.
Anyone else noticed that?
Just wondering if it's truly random, or whether it uses some other algorithm
designed to "appear more random" to the average punter who might be a bit
miffed if the machine spitted out all numbers under 10 for example?
Any statisticians in the house that can calculate the odds of all 7 numbers
being within a window of say 15 in a random pick?

Dave.

The chances of your numbers being consecutive are the same as them not
being consecutive.

Er, hardly.

The chance of any given sequence, whether consecutive or not, is the
same as the chance of any other given sequence. But that's a different
thing entirely.

Sylvia

 

[terryc]

On Thu, 02 Jul 2009 20:09:47 +1000, Sylvia Else wrote:

The chance of any given sequence, whether consecutive or not, is the
same as the chance of any other given sequence. But that's a different
thing entirely.

what are the other forms of sequence?


--
Great advances in Debian Linux; post a bug report and get spam in three
days.

 

[Phil Allison]

"terryc"

On Thu, 02 Jul 2009 20:09:47 +1000, Sylvia Else wrote:


The chance of any given sequence, whether consecutive or not, is the
same as the chance of any other given sequence. But that's a different
thing entirely.

what are the other forms of sequence?

** Anything you like - does not have to follow any rule like these do.

2,4,6,8,10,12 ....

1,3,5,7,9,11,13 ...

1,3,5,11,13,17 ....


..... Phil

 

[David Eather]

David L. Jones wrote:

OT thought for the day...
Bought my ticket for tomorrows $90M draw and was told they are the winning
numbers, so I'm sitting pretty, but I digress...
Ever since I can remember I've always noticed something with the "random"
machine picked numbers.
The numbers always seemed quite spread out, no matter how many times I've
played the random pick over the years. Occasional clumps within, but always
appers to be one number at either end etc
I would have expected sooner or later to hit upon some numbers that were all
grouped at one end or the other, or in the middle etc, but I can't ever
recall that happening.
Anyone else noticed that?
Just wondering if it's truly random, or whether it uses some other algorithm
designed to "appear more random" to the average punter who might be a bit
miffed if the machine spitted out all numbers under 10 for example?
Any statisticians in the house that can calculate the odds of all 7 numbers
being within a window of say 15 in a random pick?

Dave.

To answer your question:

The "truth" is out there, but Australian lotteries commissions are tight
lipped with the answers.

"Normally" the numbers for a "quick pick" are selected by a Pseudo
random number generator, the seed for which is periodically updated
using a clock or timer input. The most commonly used random number
generator for this purpose is a type called a "Multiply With Carry"
generator.

Imperfections come about when the generator does not have enough "state"
and so not all combinations are possible. It should be possible to check
this with the lottery commissions as if it has been implemented properly
then it makes no difference if everyone knows how it was done. If it was
done badly it may be possible to prove that some historically winning
combinations were *never* possible to pick with the PRNG, and hence,
every one who had a quick pick in those draws has a valid claim to
compensation.

My experience with Queensland golden casket is that no information is
forthcoming without an FOI application and even then they will obstruct
the process and stall beyond what is supposed to be legal.

 

[The Real Andy]

On Sun, 05 Jul 2009 02:52:15 +1000, David Eather <eather@tpg.com.au>
wrote:

David L. Jones wrote:
OT thought for the day...
Bought my ticket for tomorrows $90M draw and was told they are the winning
numbers, so I'm sitting pretty, but I digress...
Ever since I can remember I've always noticed something with the "random"
machine picked numbers.
The numbers always seemed quite spread out, no matter how many times I've
played the random pick over the years. Occasional clumps within, but always
appers to be one number at either end etc
I would have expected sooner or later to hit upon some numbers that were all
grouped at one end or the other, or in the middle etc, but I can't ever
recall that happening.
Anyone else noticed that?
Just wondering if it's truly random, or whether it uses some other algorithm
designed to "appear more random" to the average punter who might be a bit
miffed if the machine spitted out all numbers under 10 for example?
Any statisticians in the house that can calculate the odds of all 7 numbers
being within a window of say 15 in a random pick?

Dave.

To answer your question:

The "truth" is out there, but Australian lotteries commissions are tight
lipped with the answers.

"Normally" the numbers for a "quick pick" are selected by a Pseudo
random number generator, the seed for which is periodically updated
using a clock or timer input. The most commonly used random number
generator for this purpose is a type called a "Multiply With Carry"
generator.

Imperfections come about when the generator does not have enough "state"
and so not all combinations are possible. It should be possible to check
this with the lottery commissions as if it has been implemented properly
then it makes no difference if everyone knows how it was done. If it was
done badly it may be possible to prove that some historically winning
combinations were *never* possible to pick with the PRNG, and hence,
every one who had a quick pick in those draws has a valid claim to
compensation.

My experience with Queensland golden casket is that no information is
forthcoming without an FOI application and even then they will obstruct
the process and stall beyond what is supposed to be legal.

Actaully, the PRNG is typically determined by the regulator. In
Queensland, that was Knuth, now its Mersenne-Twister. Visit the OLGR
website, its all documented there somewhere.

 

[David Eather]

The Real Andy wrote:

On Sun, 05 Jul 2009 02:52:15 +1000, David Eather <eather@tpg.com.au
wrote:

David L. Jones wrote:
OT thought for the day...
Bought my ticket for tomorrows $90M draw and was told they are the winning
numbers, so I'm sitting pretty, but I digress...
Ever since I can remember I've always noticed something with the "random"
machine picked numbers.
The numbers always seemed quite spread out, no matter how many times I've
played the random pick over the years. Occasional clumps within, but always
appers to be one number at either end etc
I would have expected sooner or later to hit upon some numbers that were all
grouped at one end or the other, or in the middle etc, but I can't ever
recall that happening.
Anyone else noticed that?
Just wondering if it's truly random, or whether it uses some other algorithm
designed to "appear more random" to the average punter who might be a bit
miffed if the machine spitted out all numbers under 10 for example?
Any statisticians in the house that can calculate the odds of all 7 numbers
being within a window of say 15 in a random pick?

Dave.
To answer your question:

The "truth" is out there, but Australian lotteries commissions are tight
lipped with the answers.

"Normally" the numbers for a "quick pick" are selected by a Pseudo
random number generator, the seed for which is periodically updated
using a clock or timer input. The most commonly used random number
generator for this purpose is a type called a "Multiply With Carry"
generator.

Imperfections come about when the generator does not have enough "state"
and so not all combinations are possible. It should be possible to check
this with the lottery commissions as if it has been implemented properly
then it makes no difference if everyone knows how it was done. If it was
done badly it may be possible to prove that some historically winning
combinations were *never* possible to pick with the PRNG, and hence,
every one who had a quick pick in those draws has a valid claim to
compensation.

My experience with Queensland golden casket is that no information is
forthcoming without an FOI application and even then they will obstruct
the process and stall beyond what is supposed to be legal.

Actaully, the PRNG is typically determined by the regulator. In
Queensland, that was Knuth, now its Mersenne-Twister. Visit the OLGR
website, its all documented there somewhere.

All I said was MWC was the most used PRNG - which it is. In this regard
I said nothing about specific regulators or any choice they may have
made. I ruled out no other possibilities, so please don't put words in
my mouth.

 

[The Real Andy]

On Mon, 06 Jul 2009 11:56:15 +1000, David Eather <eather@tpg.com.au>
wrote:

The Real Andy wrote:
On Sun, 05 Jul 2009 02:52:15 +1000, David Eather <eather@tpg.com.au
wrote:

David L. Jones wrote:
OT thought for the day...
Bought my ticket for tomorrows $90M draw and was told they are the winning
numbers, so I'm sitting pretty, but I digress...
Ever since I can remember I've always noticed something with the "random"
machine picked numbers.
The numbers always seemed quite spread out, no matter how many times I've
played the random pick over the years. Occasional clumps within, but always
appers to be one number at either end etc
I would have expected sooner or later to hit upon some numbers that were all
grouped at one end or the other, or in the middle etc, but I can't ever
recall that happening.
Anyone else noticed that?
Just wondering if it's truly random, or whether it uses some other algorithm
designed to "appear more random" to the average punter who might be a bit
miffed if the machine spitted out all numbers under 10 for example?
Any statisticians in the house that can calculate the odds of all 7 numbers
being within a window of say 15 in a random pick?

Dave.
To answer your question:

The "truth" is out there, but Australian lotteries commissions are tight
lipped with the answers.

"Normally" the numbers for a "quick pick" are selected by a Pseudo
random number generator, the seed for which is periodically updated
using a clock or timer input. The most commonly used random number
generator for this purpose is a type called a "Multiply With Carry"
generator.

Imperfections come about when the generator does not have enough "state"
and so not all combinations are possible. It should be possible to check
this with the lottery commissions as if it has been implemented properly
then it makes no difference if everyone knows how it was done. If it was
done badly it may be possible to prove that some historically winning
combinations were *never* possible to pick with the PRNG, and hence,
every one who had a quick pick in those draws has a valid claim to
compensation.

My experience with Queensland golden casket is that no information is
forthcoming without an FOI application and even then they will obstruct
the process and stall beyond what is supposed to be legal.

Actaully, the PRNG is typically determined by the regulator. In
Queensland, that was Knuth, now its Mersenne-Twister. Visit the OLGR
website, its all documented there somewhere.

All I said was MWC was the most used PRNG - which it is. In this regard
I said nothing about specific regulators or any choice they may have
made. I ruled out no other possibilities, so please don't put words in
my mouth.

You said no information was forthcoming, so I gave you some
information and told you it was available on the OLGR website.

Putting more words into your mouth, here is some of that doco:
http://www.olgr.qld.gov.au/resources/gamDocs/randomNumberGeneratorsMinimumTechnicalRequirementsVerOne3.pdf

Does not mention specific PRNG but they wont approve knuth, dont like
hardware RNG and will approve MT.