Random Number Generator

[Acerak]

Tom -

As a nice exercise, maybe you can automate a routine that checks the dice rolls in every game log you have. I have a strange feeling that the game rolls a larger number of 1's than expected

-Chet

[GalakStarscraper]

Pink Horror and I are working on generating a sample to statistically test the rolls to valid the game with short term dice analysis.

It's going to take a while but we are in the process of double checking the randomizer.

We've tested the randomizers both for D6 and 2D6 rolls over a 3 sets of 100,000 and it came out fine statistically on all 6 samples.

Pink and I and now running sets of 30 rolls to test the probablity of the 20 groups of sequential rolls of 6 dice in this set (see PinkHorror's know buried post on probabilities of chains of 6 rolls of dice on the BBC ( http://pub10.ezboard.com/fbloodbowlcent ... ic&index=3 )). We will probably run 200 to 400 sets to test the the groups in the set and then the probablilites in the only the first 6 of each set as well.

Its in motion Chet, its just time consuming to reload the program 400 times to generate all the samples. We confirmed that the randomizer is working fine long term. We are now verifying that it works fine short term. Also keep in mind that the same routine that rolls the D6, rolls the Block dice and I'm pretty sure that 6 is linked to Pow and I've seen a lot of complaints about those as well. At the end of the day, it may come down to human perception.

Galak

[Dangerous Dave]

Acerak,

Back at the end of last year, similar queries were raised which prompted Galak to roll 100,000 dice 3 times - he assured us he didn't lose count!


> Okay, I ran each one of the three methods through
> 100,000 dice rolls 3 times for each method for each
> of the D6 and 2D6 rolls ..... I'll let someone with
> better statistics figure out if it all means anything.
>
> Father Tim, Martyn, or anyone else you wants
> to look it over here you go.


Father Tim ran some tests and replied:-


Okay, I crunched the numbers and ran a few tests, including chi-squared. At the 0.001 level of significance (meaning 999 times out of 1000) all three algorithms produce near-perfect distibutions.

Erwin raised an excellent point, though. We need to look at the order in which each result occurs with each algorithm. Unfortunately, I can't think of any way to do this other than sequentially examine 100,000 rolls.



So in terms of total rolls all 3 options seem to give roughly the right distribution of results. However, as far as I'm aware, no test was done on the sequence of the numbers to see if there was any problem there. Eg if the program always rolled the following sequence "1,2,3,4,5,6,1,2......", statistically the results would be accurate in terms of each roll - however, the rolls could never be said to be random - which obviously is crucial for a random number generator.


FYI, the number of ones rolled in total for all algorithms combined - was 150,141 from 900,000 dice rolls - 16 more than expected - presumably these 16 are filtering into your games! Of the 3 methods, Brian's algorithm rolled the lowest number of 1s (49,879 from 300,000 rolls) - 121 fewer than expected - perhaps you should change to that algorithm! (although Tom's method rolled 81 less than expected!). Incidently both Brian's and Tom's algorithms rolled more than the expected number of 6s...... the standard Delphi rolled more 1s and less 6s - perhaps you are using this method!!!

Here is the summary of the rolls (sorry they don't tab very well):-

Code: Select all

             Delphi                   Brian                   Tom   
Set    1st     2nd     3rd     1st     2nd     3rd     1st     2nd     3rd
1    16,711  16,775  16,855  16,337  16,784  16,758  16,669  16,664  16,588
2    16,597  16,949  16,731  16,695  16,898  16,571  16,362  16,841  16,893
3    16,616  16,544  16,622  16,721  16,637  16,693  16,950  16,563  16,666
4    16,772  16,736  16,595  16,882  16,594  16,599  16,524  16,575  16,657
5    16,646  16,363  16,721  16,696  16,560  16,523  16,651  16,561  16,606
6    16,658  16,633  16,476  16,669  16,527  16,856  16,844  16,796  16,590
    100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000

Dave

(Galak edited Dave's post to help line up the numbers for him)

[Acerak]

Thanks, guys.

-C.

[Trambi]

I think that it's a natural think, to always remember this ***** 1 roll. And the other ones.

[Acerak]

Trambi -

I agree with you in principal. It's a psychological phenomenon - you'll remember the bad stretch more clearly than you will any good luck.

But really, you have to see my games. They're rather unreal

-C.