playBunny: The parallel is that in chess like in backgammon, there are more than 2 possible results (win or loss). In chess there is the draw as well. So there is the question of what result you get after you time out. And the universally accepted solution in chess is that you get the worse possible result - that is, you get a draw if and only if the rules make impossible for you to lose.

Porting that principle to backgammon would mean that :
- By default, timing out costs a backgammon.
- If a backgammon cannot possibly be lost from the position, timing out costs a gammon.
- If a gammon cannot possibly be lost from the position, timing out costs a single game.