The most important first: I pay you $1000 if you can prove that BGBlitz has unfair dice. Easy money?

It is often told, that Backgammon programs cheat, although no evidence has ever shown. BGBlitz doesn't cheat, but you don't have to take my word, you can simply prove that yourself.

A program can cheat in two ways (if you find another way, please tell me). First it can change the rolls, so that it gets more "fortunate" numbers. You could naturally use manual dice to avoid that, but this is a little bit cumbersome. Select "Game/Random Number Configuration" and type in any number as seed e.g. 7 and "Linear Congruence" as random number generator (RNG). Now play a game and record your dice (with this example the rolls will be 26, 52, 25, 36, 15 and so on).
Now set the seed to the identical value again (i.e. 7/LC). The exact same dice will come up, ever and ever again. You may move differently, whatever you will try, the same sequence of rolls occurs totally independent of the state of the game.

The second way to cheat is to peek a little bit in the future seeing the coming rolls.
Setup any position, look which move BGBlitz chooses. Then you may setup this position again and change the value of the seed. Anytime TachiAI will select the same move totally independent of the future rolls. You can also look at the "Best Moves" dialog box. There will be the same move ordering and the same evaluation every time, totally independent of the seed.

Since version 1.9.4 you have even more transparency. On the "Game/Random Number Configuration" dialog box, you can select the RNG to use:

  • the already used "Linear congruence" generator. (the algorithm is described in Watkins: "Discrete Event Simulation in C").
  • The well known Mersenne Twister.
  • The algorithm Sun Microsystems uses for cryptographic random.
  • When connected to the internet: real random numbers from www.random.org. If not connected, the Sun algorithm is used.
  • Precalculated numbers read from a text file.
With the seed you can initialize the chosen RNG and the counter gives the number of rolls to skip from the start. Further you can (with the exception of the real random numbers) *preview* any sequence of dice rolls, so you know the *forthcoming* numbers in advance (naturally the AI isn't allowed to do that).
preview of the next rolls

If you press "Set" the RNG is initialized accordingly and you will see the corresponding rolls during the game.

state of the RNG
During the game the current state and the type of the random number generator is displayed in the upper right status bar e.g. MT 123456/2 means Mersenne Twister generator ("FI" = file based, "MT" = Mersenne Twister, "RO" = random.org, "CR" = cryptographic random), the seed was 123456 and 2 numbers are already rolled, so the current one is the third roll. So you can check the dice constantly.
I hope that now every aspect of the random number generation is transparent and easily checkable and this will convince you that the dice are fair and BGBlitz doesn't cheat...

If you still believe in biased dice you can naturally enter your own dice manually.