Jason: I don't know how a program like that can work either, but a person and a program would have one thing in common...Neither one can know for certain what the next numbers will be, but only what they could be and how it could affect your position. It seems to involve a lot of what if thinking, but nothing as precise as the kind of thinking needed in chess. In chess I know why I'm making a move, in backgammon it's more a matter of knowing what could happen next.