Re: [Bug-gnubg] Dice Rolls

[JD]

On 08/16/2013 07:56 PM, Michael Petch wrote:
> On 16/08/2013 7:35 PM, JD wrote:
> > Played5 games (me vs gnu-bg).
> > Of course, I played the best I know how for both
> > myself and gnu-bg.
> > I only won 1 game.
> > Sounds funny doesn't it?
> > I played BG against myself and I lost!!
> >
> > Well,the fact of the matter is that I was
> > astounded by the amazing dice rolls for gnu-bg
> > when I had the advantage on the board. Gnu-bg
> > got itself oout of multiple jams by dice rolls favorable
> > to itself.
> >
> > Because of what was clear to me as a preferential
> > dice rolls for gnu-bgin all 5 games, I decided that
> > the dice areskewed in favor of gnu-bg.
> >
> > Best way to test it is to have actually equally matched
> > individuals play 10 or even 100 games (or of course,
> > some might say thousands or millions of games) of Human vs Human,
> > always making note of the dice rolls for gnu-bg.
> >
> > As of right now, I am not impressed with the designers of the dice
> > roll algorithm.
> The default dice roll algorithm is actually based on Mersenne Twister.
> The source code is available and to date (After 15 years) no one has
> found the code that gives preferential treatment to the bot unless you
> set that option. GNUBG supports a number of alternative dice generation
> algorithms including manual dice (you can roll them with your own dice
> and enter manually). There is also dice generated from www.random.org
> which provides randomness through real world entropy (and isn't based on
> a pseudo random number generator. That can be set via
> Settings/Options/Dice . If you want the bot to give itself better rolls
> (or yourself) there is a mode for that. No one has found code that makes
> the bot look ahead to future rolls to make its decisions.
>
> The neural net plays at a world class level and is better (IMHO) than a
> significant majority of the players in the world. Many players also
> overestimate their own skill and don't easily accept that the bots play
> significantly better. The better someone plays the more lucky they may
> appear.
>
> I also did a statistical study (I'll see if I can dig it up) of 100
> million rolls and 10's of thousands of matches the bot played against
> itself. The results were that the rolls produced were indistinguishable
> from what you'd get with properly thrown precision dice in the real world.
>
> If GNUBG outplays a particular human consistently then my guess would be
> that the bot is better than that human.
Hello Michael,
While you can do a statistical study of the randomness of
dice rolls, it does not take into account that the engine can
see current board, and determine that it (the gnubg pseudo-player,
which is also me  - since I selected human against human, and
player 0's default name is gnubg). I find it very strange that
in 4 out of 5 games, where I was playing both as player 0 and player 1,
with player 0 being gnubg, the rolls for gnubg were incredibly
winner rolls - totally amazing to me.
So, I was not playing against the bot, as you say. I was playing
human against human, and I did not enable the "Dice Manupulation"
option at all.
But I can tell you in all honesty that I was doing my best for each roll
of the dice for both players (0, and 1).

At any rate, I do not have the skill to discern how the engine might
do what I observed, even if I peruse the source code.

Cheers,

JD