In backgammon the doubling cube is used to increase the stakes during the game. The doubling cube is a relatively new addition to backgammon but it elevates the game to a new level in terms of strategy. It is important that you know the concept and strategy elements related to the doubling cube because it might be your key to great success.
Using the doubling cube
You normally play backgammon in Match play, i.e. the winner is the player who first reaches a predetermined number of points. Every game is worth one point in the beginning of the game, so in a normal win the winner gets one point.
In the beginning each game is worth one point. On his turn before a player rolls the dice he may decide to offer the doubling cube to the opponent. If the opponent accepts the cube it is turned with number 2 facing up and the opponent takes the cube into possession, meaning that only he can initiate the next doubling. But now that the doubling cube has been used once the game is worth two points. Should the doubling cube used a second time and the opponent would accept the game would now be worth 4 points.
If a player to whom the doubling was offered doesn’t want to accept the doubling he can resign. In that case the game is finished and the winner gets as many points as the game was worth before the doubling was offered.
The doubling cube is a normal die with the numbers 2, 4, 8, 16, 32 and 64 on it. Each number represents a multiplier, which can alwas be doubled. Therefore, if the doubling cube has been used four times a single straight win would be worth 16 points. Theoretically doubling can go on forever but in reality the doubling doesn’t go beyond 4.
Optional doubling cube related rules
Beavering is often used to keep players on their toes when doubling. If a player beavers, it means that he was offered the doubling cube but simply accepting it he re-doubles to the next number! In addition he also retains control of the doubling cube. So, if the player initiating the doubling misjudged the game the opponent may grab the situation and by beavering create a nasty situation for him by beavering and a little later when he is in clear lead probably again doubling and forcing the opponent to resign.
The Crawford rule has been introduced to limit the use of the doubling cube in critical situations. It is an optional rule but a sensible one. It states that if one player has come within one point of winning the match, the game that follows is played without the doubling cube. If the player who is losing wins this game the doubling cube is again being used. Imagine a situation 4-3 in a five point game. Without the Crawford rule the losing player could blindly double on his first turn becuase he has nothing to loose anyway. The Crawford rule ensures that no weird doubling cube action is taking place in backgammon.
Scoring with the doubling cube
As mentioned above each game is worth 1 point in the beginning and the value of the game may increase with the doubling cube. So, if the doubling cube has been used twice and number 4 is facing up a single win will give the winner four points. However, if the player wins with a gammon (worth 2 points), the value of the game is multiplied by two and in a backgammon win it is multiplied by three. For example, the player won with a gammon with the doubling cube showing four he scores 4 x 2 = 8 points.