Backgammon: Basic Doubling Strategy (Part I)
Doubling is one of the most important and exacting aspects of backgammon. Good doubling decisions will often make the difference between winning and losing a series of games. Let us review the rules:
The doubling cube starts out "in the middle". That is, either player may double whenever he feels he has a significant advantage. In doubling, he offers to double the stakes of the game by turning the cube to 2 and passing it to his opponent. The double must be made when the player is on roll, but before he has rolled the dice.
His opponent then has two options:
1. He may refuse (pass) the double and lose the original one unit, thus ending the game.
2. He may accept (take) the double, in which case the game continues with a value of two units - double the original stake.
The player who has been doubled is said to own the cube, which gives him the exclusive right to re-double should he feel at any time that he is the favorite. If he re-doubles, his opponent may pass, giving up the present stake of the game - two units; or he can take, playing on at the re-doubled stake of four units.
Re-doubling can, in theory, continue on forever, keeping in mind that only the player who owns the cube (the last player to have been doubled) may offer a re-double. Experienced players seldom re-double a game beyond the four or eight level.
The question of when you possess a sufficient advantage to warrant doubling is unanswerable in easy terms. The player owning the cube has a built-in advantage in that he alone may decide whether to make the next double. You should therefore avoid doubling with a trifling advantage, for this gives your opponent ownership of the cube (which can be a powerful weapon against you) too cheaply. On the other hand, you must have the courage to double when you have a solid lead.
The double may have two effects: First, it may force your opponent to pass, thus ensuring a definite win. Failure to double allows your opponent to play on "for free" and possibly get a lucky sequence of rolls to reverse the position and win the game. In such a case you have only yourself, not the dice, to blame.
Secondly, if your opponent takes, he is now faced with a loss of twice as much. Failure to double allows him to escape with a lesser penalty than he deserves. In backgammon there is no reward for such humane treatment - your opponent cannot be expected to extend the same courtesy to you.