AbigailII:The doubling cube is not meaningless when there are draws, one must just decide what to do with draws. I thought that we would simply discard them and count them as 0-0 (like in a n-wins match). Note that it doesn't make draws meaningless. The draw rate gives more incentive to take the cube.

It sounds also possible to count a draw as 1/2-1/2, subject to doubling (a doubled draw would be 1-1, etc.). This raises the question of what to do with the Crawford rule. I suggest that when the first players reaches 1 point or half a point away of the goal, none of the players may double in the next game (note that the leader could want to double if the position is a certain draw, because a doubled draw would win the match). That variant seems to require play-testing, so the simple variant should probably be retained.