Average number of double rolls

Wipeout · Joined: 14 Jun 2007 Posts: 19

I have been playing online and have noticed that my opponent’s (be it a live person or a computer) are often rolling five or even six doubles in a game! To me, this seems like a lot and it had me wondering about the fairness of what are supposed to be random dice. Can anyone tell me what the average number of doubles that can be expected in a given game is? Would five or six doubles be unusually high?

Maddox · Joined: 14 Jun 2007 Posts: 25

The chances of rolling a double are actually 6/36 or 16.67% so it isn’t that big of a feat to roll a double. There are somewhere between twenty and thirty moves per game so the average number of doubles you could expect in a game is four or five. It really wouldn’t be that out of the ordinary for a player to roll six, or even seven in a game.

joliver · Joined: 14 Jun 2007 Posts: 25

Yeah, rolling doubles all comes down to the luck of the draw. I play backgammon with a friend who consistently rolls five or six doubles a game while I roll only two or three. Unfortunately there is nothing you can do if you aren’t “blessed” with the luck to roll doubles time and time again.

Anyhow, I think if you note down the number of doubles that you roll and that your opponent’s roll in online backgammon you will see that overtime the results will even out. Online dice are generally fair and there hasn’t been any evidence to the contrary.