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RNG workings gnu question

Posted By: Frank Berger
Date: Friday, 21 August 2009, at 6:04 p.m.

In Response To: RNG workings gnu question (bob koca)

I am seeing how much difference the score makes on a take as compared to money. So to reduce variance in the difference I use the same seed for the 2 rollouts. Will that do what I want, namely that game 1 for each rollout uses the same dice stream (until 1 game ends) that game 2 then also uses the same dice stream, ...

Yes, but setting the rng, so it is used seems to be tricky. There is currently a thread at the gnubg mailing list. The recipe by Michael Petch:

>>>>>>>> Anyway, in current releases if you wish to use the GUI and set your own seed and get the same dice rolls for an entire match do this:

A) Click "New" icon. B) Enable "Manual Dice" checkbox C) set any other player options that you wish. D) Click "Ok" E) The dice selection screen will appear. Don't select a roll, just hit "Close" E) Go to Options/Settings/Dice tab and

a) Set the random number generator to Mersenne Twister (or which ever

seeded PRNG you like)

b) set the seed to some value (3101)

c) Click "OK"

[At this point the seed is set]

F) Click anywhere on the board and you should get a message along the lines of "A new match" has been started. G) Play the match

Now do this process again and from the start with the same seed. The rolls generated should be the same.
:>>>>>>>

I assume the same holds true for rollouts. Aalthough it might be different because the rollouts with multiples of 36 and 1296 havin evenly distributed rolls for the first 1/2 rolls, but you can easily check this if you do two rollouts with identical seed and parameters.

ciao Frank

Messages In This Thread

• RNG workings gnu question
  bob koca -- Friday, 21 August 2009, at 1:08 p.m.
  • RNG workings gnu question
    Frank Berger -- Friday, 21 August 2009, at 6:04 p.m.