[CoLoCo] dice rolls in C

[David L. Willson]

ESP and psycho-kinesis are objectively provable, at least to my
satisfaction, but they do "wear out" with sheer repetition and loss of
interest, so that eventually even the most perceptive or
psycho-kinetically able subject will no longer be able to influence the
results, and their initially very non-random results will be swamped in
perfectly random results, thereby "proving" that no such thing as ESP or
psycho-kinesis exists.

On Wed, 2008-02-06 at 09:03 -0700, Jim Hutchinson wrote:
> On Feb 6, 2008 7:36 AM, Kevin Fries <kfries at cctus.com> wrote:
> > The problem with these types of "simulations" is that they rarely are
> > able to properly simulate actual dice throws.  All they are able to do
> > is pick pseudo-random numbers from an algorithm and normalize it between
> > 1 and the number of sides on the dice.  This assumes in a perfect world,
> > every number has an equal number of chances of coming up, and therefore
> > should create a situation where every number will come up an even number
> > of times, given a large enough sampling.
> 
> This is the point I'm going for. Dice rolling is actually one of the
> true forms of random number generating. Computers are psuedo-random
> and we want to "see" how that actually plays out. We want to see that
> these these generators are not truly random. The reality, however is
> that they are very good. I ran the C program with 10 million rolls and
> 10 billion rolls and the results just got closer to the theoretical
> probabilities. I was going to run it 10 trillion times but it was
> going to take more than 10 days. I was hoping to see periodicity and
> maybe it's there. Maybe my test isn't sophisticated enough.
> 
> >
> > The problem with this exercise is that it is neither random (has to do
> > with how RPG works at the lowest level) nor accurate.  In a physical
> > world, the dice throws are never truly random either.  Watch someone
> > throw a pair of dice say 20 times.  Every time they will pick the dice
> > up in a particular way, roll them in their hands in a particular way,
> > and toss them in a particular way.  Each of these ways are as unique as
> > the player.  Note the numbers that come up.  Then repeat the experiment
> > with four other players.  Due to the differences in the way each person
> > will do it, you will find, despite what you would think, certain numbers
> > will come up more often for certain players.  This is one area where
> > theory and reality are very different from one another.
> 
> This is a common misconception. While with a small sample you may see
> certain number come up more often (you should see 7 more often because
> it has the highest probability but with small samples that doesn't
> always happen) the rolls are still random in that each roll is not
> dependent upon any roll before - as long as you aren't just dropping
> them from 2 inches with the numbers you want showing. Rolling a 7 on
> one roll will not impact the odds of rolling a 7 or any other number
> on the next roll. Each roll is independent. Given a large enough
> sample this becomes obvious. 1000 rolls is not large enough and 20 or
> 30 is way too small. Using the true random number generator at
> random.org I simulated 5000 dice rolls and the frequencies are exactly
> what you would expect. If they would let you do 10 million it would no
> doubt be even more perfect. 500 rolls wasn't bad either but you could
> see the variability inherent in small samples.
> 
> > As a casino, having
> > higher paying hands come up more often turns a winning machine into a
> > losing one.
> 
> Casinos don't lose in the long run though because the odds are in
> their favor. Given a large enough sample (like years and years of
> playing) the casino always wins. Slot machines pay back around 97-98%
> but if you continually lose 2% of your money you will eventually have
> none left and the casino will have it all. It's called gambling
> because you might get luck and hit a large payout. If you stop you
> walk away a winner. If you keep playing you will give it all back.
> 
> Thanks again to all for the great discussion and information. I'm
> still not sure how we are going to set this up as a true experiment
> that a 6th grader can reasonably understand, do and explain.
> 
> -jim
> 
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