vpFREE2 Forums

Pseudo-random number generators and Murder

#1

For those still interested in this thread, I offer the following:

Court records demonstrate that vp machines have been gaffed in Nevada
in the past, HOWEVER, these were all at small " mom and pop" bars
with a handful of machines. A $4,000 royal could create serious cash-
flow problems for some of these establishments, hence a programmer
made a little after-market fix to prevent those pesky royals, I
believe he ended up getting murdered for his trouble.

Now, I believe it would be beyond foolish for a major casino
operation to knowingly gaff their machines. They really don't have,
just lower the pay-schedules offered. I believe the advantage Las
Vegas locals on this site have a distorted view of the percentage of
vp players who "know what they are doing". Let me offer this example
(great by local standards) machines (NSUD, 9/6 JOB, 99.8% TDB) they
even went so far as to put a flashing sign above the machines saying
that these machines all pay above 99%. Right next to these machines
are inferior versions of the same games. Which set of machines do you
think are busier day after day...you guessed it the inferior
machines. Some people not only don't mind inferior pay schedules,
they DEMAND them.

Onto pseudo-random number generators (prng). Generating pseudo random
numbers is not as easy as you might think, most prng tend to
deteriorate over time and produce biased results, that is why they
often need to be "reset". I believe it is possible for the prng to be
temporarily biased, both in favor and against the player, however, I
would expect this bias to wash-out in the long run. Although, if a
bug in the software prevented the prng from resetting after the
appropriate number of cycles, it could end up with a lasting bias in
the outcomes.

I'm not sure if this is "urban legend", but , I heard this story:
Several years ago, on one of the river-boats that would turn-off all
the slot machines at the end of the gaming day and then restart the
machines at the same time each day. Well, the prng took the seed
number from ths slot machine's internal clock, hence each day the
machines would run through the same initial cycle, and hence could be
easily beat...until the next seed reset.

···

from my local market. Harrah's recently put in a bank of 10 good

#2

I recall something about the Casino de Montreal. They closed every morning at 3 or 4 am and powered off the machines until opening time. An accountant came in every day after work to play Keno for an hour or so, and picked up on the fact that the winning numbers had some sort of repeat. Apparently he won around $200k. When they hauled him in, he explained how he won. He ended up keeping the money, and the casino went to 24-hour powerup.

···

jaydavidson118 <jaydavidson118@yahoo.com> wrote:
I'm not sure if this is "urban legend", but , I heard this story:
Several years ago, on one of the river-boats that would turn-off all
the slot machines at the end of the gaming day and then restart the
machines at the same time each day. Well, the prng took the seed
number from ths slot machine's internal clock, hence each day the
machines would run through the same initial cycle, and hence could be
easily beat...until the next seed reset.

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#3

There was also the case profiled on TV (Discovery or Travel channel)
where the guy who worked for the Nevada gaming commission and figured
out how the Keno results could be predicted, I believe he said he
could predict all nine? numbers, I don't play Keno, with 3%
certainty...that's huge! Assuming vp random number generator works
similarly, perhaps all vp games can be beat.
Let's hear it for pseudo-random number generators.

I recall something about the Casino de Montreal. They closed every

morning at 3 or 4 am and powered off the machines until opening time.
An accountant came in every day after work to play Keno for an hour
or so, and picked up on the fact that the winning numbers had some
sort of repeat. Apparently he won around $200k. When they hauled him
in, he explained how he won. He ended up keeping the money, and the
casino went to 24-hour powerup.

jaydavidson118 <jaydavidson118@y...> wrote:
I'm not sure if this is "urban legend", but , I heard this story:
Several years ago, on one of the river-boats that would turn-off

all

the slot machines at the end of the gaming day and then restart the
machines at the same time each day. Well, the prng took the seed
number from ths slot machine's internal clock, hence each day the
machines would run through the same initial cycle, and hence could

be

···

--- In vpFREE@yahoogroups.com, Brian Lavoie <blavoie46@y...> wrote:

easily beat...until the next seed reset.

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#4

I use Excel to teach statistics to first year Marketing students. If I have my students generate random samples from a population and then calculate the sample mean-well guess what, all 25 students get the same random numbers and the same sample mean. The program always uses the same random seed when it generates random numbers. It will go to the same seed every time you start up Excel. If you generate a second random sample it will have different numbers as long as you don't quit the program and start over all again. So your story may not be an urban myth.

Myra

···

On 9-Dec-04, at 1:23 PM, jaydavidson118 wrote:

I'm not sure if this is "urban legend", but , I heard this story:
Several years ago, on one of the river-boats that would turn-off all
the slot machines at the end of the gaming day and then restart the
machines at the same time each day. Well, the prng took the seed
number from ths slot machine's internal clock, hence each day the
machines would run through the same initial cycle, and hence could be
easily beat...until the next seed reset.

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#5

I dunno for certain but I would bet money that this is an urban
legend. It's true that computers often use the clock value as a seed
for their random number generators. However, my understanding is that
the precision is such that there's no way we humans can use that
knowledge to predict random numbers, even in the cases cited here.
They strip digits off the "clock" (a 15-20 digit number, with whole
days from some start point to the left of the decimal and the
fraction of the current day elapsed to the right) in the fractions of
seconds range to use as the seed. Thus the power would have to come
on at precisely the same time down to a nanosecond or so.
For example, go into MS Excel and type the function =NOW(). Then
change the format to make it read like a number with 12 decimal
places. You will see there are 10 digits to the right of the decimal.
One second is 1/(24*60*60) or about 0.00001 so that 10th digit is
something like 1/100,000 of a second.

I recall something about the Casino de Montreal. They closed every

morning at 3 or 4 am and powered off the machines until opening time.
An accountant came in every day after work to play Keno for an hour
or so, and picked up on the fact that the winning numbers had some
sort of repeat. Apparently he won around $200k. When they hauled him
in, he explained how he won. He ended up keeping the money, and the
casino went to 24-hour powerup.

jaydavidson118 <jaydavidson118@y...> wrote:
I'm not sure if this is "urban legend", but , I heard this story:
Several years ago, on one of the river-boats that would turn-off

all

the slot machines at the end of the gaming day and then restart the
machines at the same time each day. Well, the prng took the seed
number from ths slot machine's internal clock, hence each day the
machines would run through the same initial cycle, and hence could

be

···

--- In vpFREE@yahoogroups.com, Brian Lavoie <blavoie46@y...> wrote:

easily beat...until the next seed reset.

---------------------------------
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Read only the mail you want - Yahoo! Mail SpamGuard.

[Non-text portions of this message have been removed]

#6

There are two ways to "seed" a RNG. You can use the
same starting number each time or you can use a number
generated by the clock (or some other source of
constantly changing numbers).

If you use the same number each time, the sequence
produced by the RNG will always be the same and I
believe this is supposed to be what happened with the
machines in the story. I don't know if the story is
true or not. It seems pretty naive to me for the
engineers to think no one would notice!

carlos

I dunno for certain but I would bet money that this
is an urban
legend. It's true that computers often use the clock
value as a seed
for their random number generators. However, my
understanding is that
the precision is such that there's no way we humans
can use that
knowledge to predict random numbers, even in the
cases cited here.
They strip digits off the "clock" (a 15-20 digit
number, with whole
days from some start point to the left of the
decimal and the
fraction of the current day elapsed to the right) in
the fractions of
seconds range to use as the seed. Thus the power
would have to come
on at precisely the same time down to a nanosecond
or so.
For example, go into MS Excel and type the function
=NOW(). Then
change the format to make it read like a number with
12 decimal
places. You will see there are 10 digits to the
right of the decimal.
One second is 1/(24*60*60) or about 0.00001 so that
10th digit is
something like 1/100,000 of a second.

--- In vpFREE@yahoogroups.com, Brian Lavoie
<blavoie46@y...> wrote:
> I recall something about the Casino de Montreal.
They closed every
morning at 3 or 4 am and powered off the machines
until opening time.
An accountant came in every day after work to play
Keno for an hour
or so, and picked up on the fact that the winning
numbers had some
sort of repeat. Apparently he won around $200k. When
they hauled him
in, he explained how he won. He ended up keeping the
money, and the
casino went to 24-hour powerup.
>
> jaydavidson118 <jaydavidson118@y...> wrote:
> I'm not sure if this is "urban legend", but , I
heard this story:
> Several years ago, on one of the river-boats that
would turn-off
all
> the slot machines at the end of the gaming day and
then restart the
> machines at the same time each day. Well, the prng
took the seed
> number from ths slot machine's internal clock,
hence each day the
> machines would run through the same initial cycle,
and hence could
be
> easily beat...until the next seed reset.
>
>
>
>
>
> ---------------------------------
> Do you Yahoo!?
> Read only the mail you want - Yahoo! Mail
SpamGuard.
>
> [Non-text portions of this message have been
removed]

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···

--- blaw57 <blaw57@yahoo.com> wrote:

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#7

Not necessarily slot machines, but some machines with RNGs use ambient temperature as a seed as well as motor movement, key presses, and other environmental and unpredictable factors.

When I created a PHP signature key for secure email, I had to move my mouse around for a minute and my computer used this movement as a seed to create my PHP key.

DB in SD

Carlos Lebron wrote:

···

There are two ways to "seed" a RNG. You can use the
same starting number each time or you can use a number
generated by the clock (or some other source of
constantly changing numbers).

If you use the same number each time, the sequence
produced by the RNG will always be the same and I
believe this is supposed to be what happened with the
machines in the story. I don't know if the story is
true or not. It seems pretty naive to me for the
engineers to think no one would notice!

carlos

--- blaw57 <blaw57@yahoo.com> wrote:
>
> I dunno for certain but I would bet money that this
> is an urban
> legend. It's true that computers often use the clock
> value as a seed
> for their random number generators. However, my
> understanding is that
> the precision is such that there's no way we humans
> can use that
> knowledge to predict random numbers, even in the
> cases cited here.
> They strip digits off the "clock" (a 15-20 digit
> number, with whole
> days from some start point to the left of the
> decimal and the
> fraction of the current day elapsed to the right) in
> the fractions of
> seconds range to use as the seed. Thus the power
> would have to come
> on at precisely the same time down to a nanosecond
> or so.
> For example, go into MS Excel and type the function
> =NOW(). Then
> change the format to make it read like a number with
> 12 decimal
> places. You will see there are 10 digits to the
> right of the decimal.
> One second is 1/(24*60*60) or about 0.00001 so that
> 10th digit is
> something like 1/100,000 of a second.
>
> --- In vpFREE@yahoogroups.com, Brian Lavoie
> <blavoie46@y...> wrote:
> > I recall something about the Casino de Montreal.
> They closed every
> morning at 3 or 4 am and powered off the machines
> until opening time.
> An accountant came in every day after work to play
> Keno for an hour
> or so, and picked up on the fact that the winning
> numbers had some
> sort of repeat. Apparently he won around $200k. When
> they hauled him
> in, he explained how he won. He ended up keeping the
> money, and the
> casino went to 24-hour powerup.
> >
> > jaydavidson118 <jaydavidson118@y...> wrote:
> > I'm not sure if this is "urban legend", but , I
> heard this story:
> > Several years ago, on one of the river-boats that
> would turn-off
> all
> > the slot machines at the end of the gaming day and
> then restart the
> > machines at the same time each day. Well, the prng
> took the seed
> > number from ths slot machine's internal clock,
> hence each day the
> > machines would run through the same initial cycle,
> and hence could
> be
> > easily beat...until the next seed reset.

#8

<<I dunno for certain but I would bet money that this is an urban legend.>>

Don't bet it - it IS true - happened in Canada on a keno game. Widely-reported in many reliable sources.

···

________________________________________
Jean $¢ott - Go to http://www.FrugalGambler.biz
  for VP software and strategy cards and for the
  Frugal series of books.

[Non-text portions of this message have been removed]

#9

..if it wasn't 5 in the morning and I've had no coffee
yet, I could think of a joke about the machines
"running hot or cold"....

carlos

···

--- Devin Braun <dbraun4@yahoo.com> wrote:

Not necessarily slot machines, but some machines
with RNGs use ambient
temperature as a seed ....[etc]

#10

Excellent post. I agree, particulary that many Vegas locals on this board, over estimate visitors VP skill.

···

jaydavidson118 <jaydavidson118@yahoo.com> wrote:
For those still interested in this thread, I offer the following:

Court records demonstrate that vp machines have been gaffed in Nevada
in the past, HOWEVER, these were all at small " mom and pop" bars
with a handful of machines. A $4,000 royal could create serious cash-
flow problems for some of these establishments, hence a programmer
made a little after-market fix to prevent those pesky royals, I
believe he ended up getting murdered for his trouble.

Now, I believe it would be beyond foolish for a major casino
operation to knowingly gaff their machines. They really don't have,
just lower the pay-schedules offered. I believe the advantage Las
Vegas locals on this site have a distorted view of the percentage of
vp players who "know what they are doing". Let me offer this example
from my local market. Harrah's recently put in a bank of 10 good
(great by local standards) machines (NSUD, 9/6 JOB, 99.8% TDB) they
even went so far as to put a flashing sign above the machines saying
that these machines all pay above 99%. Right next to these machines
are inferior versions of the same games. Which set of machines do you
think are busier day after day...you guessed it the inferior
machines. Some people not only don't mind inferior pay schedules,
they DEMAND them.

Onto pseudo-random number generators (prng). Generating pseudo random
numbers is not as easy as you might think, most prng tend to
deteriorate over time and produce biased results, that is why they
often need to be "reset". I believe it is possible for the prng to be
temporarily biased, both in favor and against the player, however, I
would expect this bias to wash-out in the long run. Although, if a
bug in the software prevented the prng from resetting after the
appropriate number of cycles, it could end up with a lasting bias in
the outcomes.

I'm not sure if this is "urban legend", but , I heard this story:
Several years ago, on one of the river-boats that would turn-off all
the slot machines at the end of the gaming day and then restart the
machines at the same time each day. Well, the prng took the seed
number from ths slot machine's internal clock, hence each day the
machines would run through the same initial cycle, and hence could be
easily beat...until the next seed reset.

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#11

Good one! Perhaps, you don't need that cup of coffee after all.

···

--- In vpFREE@yahoogroups.com, Carlos Lebron <calebr0n@y...> wrote:

..if it wasn't 5 in the morning and I've had no coffee
yet, I could think of a joke about the machines
"running hot or cold"....

carlos

--- Devin Braun <dbraun4@y...> wrote:

>
> Not necessarily slot machines, but some machines
> with RNGs use ambient
> temperature as a seed ....[etc]

#12

This is not an urban legend. For a good discussion of PRNG and the details of the real story, see

http://catlin.casinocitytimes.com/articles/1243.html

or

http://users.andara.com/~brsears/notrand.htm

Her's a press report from the time:

_The Toronto Star_
Wednesday, April 20, 1994

`Computer nerd' outsmarts casino

Wins $200,000 pot -- twice in a row

MONTREAL (CP) -- Ask Daniel Corriveau how he beat
staggering odds to win $400,000 at the Montreal
casino and he'll talk about a butterfly flapping
its wings in Bejing.
    After the computer consultant hit a $200,000
jackpot twice in a row playing electronic Keno 10
days ago, the casino shut down the popular
lottery-type game and started an investigation.
He has yet to collect.
    "I'm confident I will get the money," Corriveau
said. "It's a normal process for the casino to be
investigating."
    Celebrated by Quebecers as a mild-mannered genius
who beat the system, the province's latest hero
is a computer nerd who claims to have used "chaos
theory" to defy mind-numbing odds at the casino.
    The arcane mathematical concept, which the 40-year
old Corriveau found himself expounding on television,
is based on the notion that random-looking data aren't
so random.
    One of the theory's axioms is that if a butterfly
flaps its wings in Bejing, it will have an effect on the
weather system in New York City.
    The rules of Keno are less esoteric. Placing bets
of between $2 and $5, gamblers try to pick some of the
20 numbers that are drawn from an 80-number pool in
the computerized game.
    On April 10, Corriveau managed to pick 19 of 20
numbers twice in a row, a feat not accomplished even
once since the casino opened last October.
    Corriveau said he discovered "a bug in the system"
that made the Keno odds more player-friendly.
    Corriveau visited the casino about a dozen times
over four months, writing down the winning sequences
of numbers. The brainy bettor plugged the data in
to his home computer and put on his thinking cap.
    "I found the same 19-number sequence twice in 240
draws," he explained, "That proved the weakness in
the system."

#13

Interesting! That is exactly what Excel does. If you quit Excel, restart it, and then generate a random sample from a population you will get exactly the same numbers as before. Excel will go to the identical seed and just repeat the random numbers.

Myra

···

On 10-Dec-04, at 3:34 PM, Dick Kalagher wrote:

This is not an urban legend. For a good discussion of PRNG and the details
of the real story, see

http://catlin.casinocitytimes.com/articles/1243.html

or

http://users.andara.com/~brsears/notrand.htm

Her's a press report from the time:

_The Toronto Star_
Wednesday, April 20, 1994

`Computer nerd' outsmarts casino

Wins $200,000 pot -- twice in a row

MONTREAL (CP) -- Ask Daniel Corriveau how he beat
staggering odds to win $400,000 at the Montreal
casino and he'll talk about a butterfly flapping
its wings in Bejing.
    After the computer consultant hit a $200,000
jackpot twice in a row playing electronic Keno 10
days ago, the casino shut down the popular
lottery-type game and started an investigation.
He has yet to collect.
    "I'm confident I will get the money," Corriveau
said. "It's a normal process for the casino to be
investigating."
    Celebrated by Quebecers as a mild-mannered genius
who beat the system, the province's latest hero
is a computer nerd who claims to have used "chaos
theory" to defy mind-numbing odds at the casino.
    The arcane mathematical concept, which the 40-year
old Corriveau found himself expounding on television,
is based on the notion that random-looking data aren't
so random.
    One of the theory's axioms is that if a butterfly
flaps its wings in Bejing, it will have an effect on the
weather system in New York City.
    The rules of Keno are less esoteric. Placing bets
of between $2 and $5, gamblers try to pick some of the
20 numbers that are drawn from an 80-number pool in
the computerized game.
    On April 10, Corriveau managed to pick 19 of 20
numbers twice in a row, a feat not accomplished even
once since the casino opened last October.
    Corriveau said he discovered "a bug in the system"
that made the Keno odds more player-friendly.
    Corriveau visited the casino about a dozen times
over four months, writing down the winning sequences
of numbers. The brainy bettor plugged the data in
to his home computer and put on his thinking cap.
    "I found the same 19-number sequence twice in 240
draws," he explained, "That proved the weakness in
the system."

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#14

While some very old VP machines may have suffered from poor prng
routines (either from bad programming and/or inferior processing
power), you can bet that all modern VP machines are far more
sophisticated. There are undoubtedly some complicated re-seeding
routines running to reduce the odds of the "repeating" problem.

But even if that weren't the case and you could figure out how to
duplicate the sequence of numbers the PRNG generates, there are
multiple obstacles that would make it impossible to use that
information to predict upcoming hands, at least from a practical
standpoint.

First, you'd need to know the actual algorithm used to translate the
series of random numbers into cards that produce VP hands.

Second, the PRNG runs so fast you'd need a dual computer running next
to the machine to keep up with the numbers and stay in sync with the
VP machine.

Third, modern VP (and slot) machines continue to "shuffle" between
hands. That means they're running off hundreds or even thousands of
random numbers every second. The hand you see on the deal is
determined by the timing at which you hit the deal button (or drop the
first coin in). A split second delay and you get a totally different
hand. So even if you could duplicate the prng algorithm, the seeding
routines, the card translations, and have all this running on a
computer next to the VP machine, you'd still need the ability to hit
the button with super-human precision. Unless IGT starts installing a
USB port next to the deal button, consider all this effectively
impossible.