Backgammon NJ: Dice Rolls
How random number generators work:
Backgammon NJ uses the Mersenne Twister algorithm to generate random numbers. This is similar to how the majority of computer programs generate random numbers. The algorithm starts with a Seed (a number). Using this Seed, the algorithm produces an unending sequence of random numbers. Each different Seed generates a different sequence. If you record a particular Seed, you can generate its sequence again by restarting the algorithm with that Seed.
Each time you run Backgammon NJ, it chooses its Seed based on the system clock. The Seed chosen is the number of seconds that have elapsed since Jan 1, 1970. This ensures that you will never get the same sequence of dice twice as long as you don't turn back your clock.
At the bottom of the Settings window, you can find the RNG (Random Number Generator) Seed that was chosen when you started the game. By using the Seed listed, you can generate the exact sequence of dice rolls that the game is using. You can then check the roll sequence against the rolls (both past and future) in the game to convince yourself that the rolls are not being altered to benefit the computer. You should be able to verify that the rolls are based solely on the Seed and not based on any knowledge about the game or position.
How to use the RNG Seed to print out dice rolls:
Each time you run Backgammon NJ, it chooses a new RNG Seed. If you wish to analyze dice rolls for a particular RNG Seed, you must keep Backgammon NJ running, set the RNG Seed to the proper value (in the Settings window) the next time you run the app, or set the "Save RNG Seed" option to "On".
To generate the dice rolls, enter the RNG Seed and the Number of Rolls to generate into the form below. Then, click the Submit button.
The dice rolls will be printed in rows of 10 from left to right, starting with the first roll (roll #0). The Next Roll Number in Backgammon NJ is shown in the Settings. You can use this to compare the printout of dice rolls with the ones the computer generates in Backgammon NJ at any point in time.
For example, in the screenshot above, the RNG Seed is 1262415540 and the Next Roll Number is 6.
The computer does not cheat by looking at upcoming dice rolls:
Backgammon NJ does not cheat by looking at upcoming dice rolls. To prove this, follow these steps.
Dice roll generator program with source code:
If you want to run the dice roll generator program on your desktop computer instead of through our website, we're making it available for download as both a windows executable and in source code form. Download it here.
What this feature is used for:
This feature was added primarily to address the claims of those who think that Backgammon NJ is cheating because they cannot win against the AI. Read more about this here.