
About us	Contact us	Site map

Double Trouble II

The backgammon position below is a taken from a money game, but the cube decision here applies to many match situations as well. Black is in a very interesting position and has a very enviable problem. He’s been doubled and he’s obviously turned the game around some, and he’s debating whether or not he should redouble. But with any doubling situation, there are really two questions to consider:

1. Should Black redouble?
2. If Black redoubles, should White take or drop?

One of the best ways to come to the answer to question 1 is to first answer question 2. Before you decide to give a cube (double) you should consider what you think your opponent should do. If you are SURE your opponent will or should drop, then you’ve got a great double. If you are SURE your opponent will or should take, then you may still have a double, but you need to give it more thought. You need to decide how much you would like to continue playing this game with your opponent holding the cube. And lastly, if you are not sure if he should take or drop, the FOR SURE, you should double.

It’s when you are unsure that a cube is an excellent cube, because if you are not sure, there’s a reasonable chance that neither is he. You might be a wrong if you double, and you might be wrong if you don’t double, but if you double, you also give your opponent a chance to make a mistake. You NEVER give him a chance to make a mistake if you don’t double.

In this situation, the answer to No. 2 is that CLEARLY white should take! There is no doubt it is a take, even though he is losing, for many reasons:

He can’t get gammoned but he can still win a gammon. If things go bad, he loses 4 points, but if he gets lucky he might even win 8 points.
Black still has a lot of work to do to win this game. He needs to close out his board and hold White in while he brings a lot of checkers around the board.
Even if Black completely closes his board, White already has 6 checkers off and he still has a chance to win. Black could open up a point before taking many checkers off and if White comes in quickly and rolls one big double, it’s his game. Or, Black could leave a shot bearing off, and if White hits it, again he has an excellent chance.

So if you agree that White has a clear take, that doesn’t mean Black shouldn’t double. To really get the answer on this, experts use the computer programs. I put this into Snowie and it told us some very interesting information.

What the Snowie evaluation tells us is that Black will win this game 76% of the time. White only wins 24% of the time, but look at the next number, because that’s a key number. The 8.7% is the percentage of times that White will win a gammon (and he even wins backgammons about 1 percent of the time).

But there is something else very important that is not stated in the above evaluation. One of the reasons that Black will win this game 76 percent of the time is because he holds the cube. If he continues to hold the cube and things go well on the next roll or two, he will win the game by turning the cube and getting a drop from white! If he gives away the cube now and white takes, he can no longer end the game that way. That means that if he gives the cube he will win the game less…my guess is that instead of winning 76% his win percentage will go down to something like 65 percent. So BY TURNING THE CUBE HE GIVES AWAY OVER 10 PERCENT OF HIS WINS.

If Black wins 10 percent less by turning the cube, it means White wins 10 percent more. The net effect is that when you add the two together, Black loses 20 percent of his net equity, or profit, (or dollars if you are playing backgammon for money) by turning the cube here.

Just about every time you give a cube you face this issue, but the amount you are giving away here if things go wrong, including the gammon risks, all add up to a “no cube” as the proper decision.