The Doubling Cube
Idiot's Guide to the Doubling Cube
by Phil Simborg, 2008
Phil Simborg
The game of backgammon has been around for centuries, but the doubling cube is only about 60 years old. My guess is somebody slaughtered his best friend or wife or someone in a game of backgammon and didn't see enough suffering, so he invented the cube.

The idea of the cube is to allow either party to double the stakes of the game. Instead of playing for $1.00, you can raise the bet to $2.00 or force your opponent to quit and pay you the $1.00. And when you double the stakes of the game, you are also doubling the cost for gammons (which is double the cube) and backgammons (which is triple the cube).

So why should you play with the cube? Some say because it makes the game more fun, interesting, and challenging. Others say it makes the game more complicated and intellectually stimulating. The truth is, it's the doubling cube that really makes backgammon known as "the cruelest game."

Doubling Cube In poker, when you think you have the better hand, you want to raise the stakes. So you make a bet. Using the doubling cube is the way to raise the stakes in backgammon. In poker, there are hidden cards and bluffing, but in backgammon, all the cards are on the table.

So let's say you are playing a money game and you are playing someone for, let's say, $1 a point. If you are winning, wouldn't you rather play for twice as much? So, it seems, giving the cube is easy. If you're winning ... give the cube.

The rules say you can only double when it is your turn to roll, and you must give the cube before you roll. But there's a problem giving the cube just because you're winning. Your opponent just might take it. And once he is holding the cube, if he gets to a winning position, he can give the cube back to you at double whatever you gave it to him for. So you give him the cube at 2, and he can give it back at 4.

The tricky thing about the doubling cube is that it truly is a weapon. If the cube is in the middle, it is a weapon either player can use, but once one of the players has the cube, only he can use it. And just because he has that weapon, his odds of winning actually go up. As we all know, games change with every roll, and the person who might be ahead at one point might find himself behind a few rolls later. The person with the cube is the one who has the weapon that he can use to either end the game or double the pressure on the other player.

So the lesson here is that you should not give the cube too soon or too lightly.

Now, what about taking the cube? Why should you take the cube if you are losing the game? The answer is, if you drop the cube just because you are losing a little, you lose more money than if you take the cube and win once in a while. In fact, in a money game, if you can win only 1 out of 4 games (25 percent) you are better off taking the cube than dropping it. Of course, you also have to consider gammons and backgammon risks, and that makes things more complicated, but generally, 25 percent is the key number.

When you play matches, the cube becomes incredibly more complicated, because differences in score drastically change that 25 percent number, and the value of winning or losing gammons and backgammons also changes. I know players who have studied the game seriously for many years and still don't completely understand these odds and calculations, they can get so complicated. So I won't try to go into detail on this here.

I do want to say that if you are a beginner, or relatively new to backgammon, and you are not playing with the doubling cube, that's okay. For starters. Playing without the cube allows you to concentrate strictly on checker play and allows you to complete every game and see how it plays out. But once you get a little more experienced, I strongly recommend you add the doubling cube to your game. It is a lot more fun and exciting and I promise you, you will enjoy the game more.

Phil Simborg is a fulltime backgammon player and teacher.
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