Two Points To Go
Kit Woolsey, 1980
Las Vegas Backgammon Magazine, October 1980

Kit Woolsey
Several years ago when I played in my first big backgammon tournament, I was fortunate enough to reach the quarterfinals. The score progressed to 19–19 in the 21-point match. I started with 3-1 and 4-2, while my opponent's first two rolls accomplished nothing much. I then chose to double, figuring that I might as well put the match up for grabs while I had an advantage. He took, and I eventually lost the game and the match.

Afterward, I asked a couple of good players if my double was correct. The general consensus was that it was a good double if my opponent dropped, but otherwise it was questionable. As we shall see, I actually doubled one roll too late!

A couple of years later I was kibitizing a 15-point match at the European championships, along with Al Lorenz, one of Europe's best players. The score progressed to 13–13, at which point Al whispered to me, "If these guys know what they are doing, the next game should be the last game of the match."

At the time this seemed to be somewhat of an overstatement. I knew that it was correct to double earlier than usual at this score, but is it right to always double so early that it becomes a take, regardless of the sequence of rolls? It turns out upon careful analysis that Al was quite correct. With proper play at this score, no double should be made so late that the opponent has as drop.

The argument for doubling on any advantage when each side has two points to go in a match can be seen by examining the possible costs of being wrong by doubling or not doubling. Suppose we start with a 3-1 roll, making our 5 point, and our opponent rolls 3-2, bringing two men down.

 15 13 13
Should White double?
The cost of being wrong by not doubling is the same as always — we might roll a joker such as 4-4 or 6-6 on our next roll, and our opponent will now have a drop when we would have preferred to play the game for the match.

Now, what is the cost of doubling when things fail to go well immediately? We lose the opportunity to double our opponent out later, but should that situation arise we will be happy to have already doubled. Suppose the game turns around. If the cube is still in the middle, and our opponent knows what he is doing (i.e., if he has read this article), he will double early enough that we will still have to take. Consequently, we will be playing the game for the match whether we double now or not, even if things go sour and we lose our advantage. Therefore, there is no cost at all in doubling immediately if we are wrong, so we should double now to avoid the risk of losing our market.

Another way of seeing the argment is as follows: The reason we do not double on a slight advantage in regular money play is that our opponent would then own the cube, which means that he has the option for the rest of the game of jacking the stakes up to 4, while we do not have that option. However, when each side has two points to go in the match, this cube ownership becomes worthless. Consequently, we are giving away nothing by giving away the cube, so we should double if it is at all possible that we will lose our market on the next roll.