frolind:
The odds change with every throw of the dice. There are only so many times one can get a 6-6, or a 5-5, or a double anything in one game. I think the odds are that any combination of dice thrown will be equivalent to a 7, but we all know that backgammon, winning at backgammon, can turn on the doubles. So when a player has to throw the dice and cannot move anyway...IT CHANGES THE ODDS!