Backgammon Dictionary

In a chouette, members of the team who play with the captain against the box.

The movement of a checker from one quadrant of the board to an adjacent quadrant.

The total number of crossovers needed to get all your checkers home and then borne off.

The forced evacuation of desirable points (2) due to the lack of alternate plays; in particular, a position in which you are forced to bury checkers deep within your home board.

A position which has collapsed, with several checkers being forced to the low points (1) in the player's home board while other checkers remain in the opponent's territory.

A priming game in which one side is about to collapse, but has not done so yet.

[Noun.]  Doubling cube.

[Verb.]  To offer a double.

All of the cube decisions associated with a given position, namely: (a) whether the player on roll should double, and (b) whether his opponent should accept the double, refuse the double, or possibly beaver.

The choice of whether or not to offer a double, or the choice of whether to accept, or refuse a double that has been offered.

In money play with the doubling cube, the absolute value of a position to one of the players compared to the initial stake being played for.  See: Equity. Cubeful equity considers the current value of the cube, cube ownership, and the potential for future doubles. In match play, cubeful equity corresponds to the probability of winning the match from the current position.  Compare: Cubeless Equity.

A rollout performed with the doubling cube in play. All appropriate cube decisions are made as the position is played out. That means some trials will end in a dropped double and others will end with the cube at 2, or 4, or even higher. Cubeful rollouts more accurately simulate actual games than cubeless rollouts, but they have greater variance, so they do not converge as quickly. And cubeful rollouts may be more susceptible to systematic error because of cube misplays.

The art or skill of making cube decisions.

See: Centered Cube.

The value of a position if the game is played without a doubling cube. This is a value between -3 and +3 and is equal to P(W) + P(Wg) + P(Wbg) - P(L) - P(Lg) - P(Lbg), where P(W) is the probability of winning the game, P(Wg) is the probability of winning a gammon (or backgammon), P(Wbg) is the probability of winning a backgammon, P(L) is the probability of losing the game, P(Lg) is the probability of losing a gammon (or backgammon), P(Lbg) is the probability of losing a backgammon.  Compare: Cubeful Equity.

The chance of winning the game if no doubling cube is used; also called game winning chances.

Which player has the right to make the next double. At the start of the game, the cube is in the middle and either player may double. After one player accepts another's double, he owns the cube, and only that player may make the next double.

The act of offering a double, or the act of accepting or refusing the opponent's double.

The art or skill of making cube decisions.  Compare: Checker Play (2).

An error in checker play that induces the opponent to double on his turn. The ploy could be intentional, an attempt to get the opponent to double too early, but the term "cube provocation play" is often used mockingly to refer to an obvious error.   See:  Danny Kleinman (1980) "Cube Provocation Play".

A correct checker play that leads the opponent to correctly double when at least one other play is available after which the opponent would be wrong to double. This can happen if the better play produces a more volatile position -- the opponent is forced to double because he has too many market losers. Examples are Wisecarver Paradox positions.

A player in a chouette who temporarily handles the cube for another while that player is away from the game. See post by Ilia Guzei.

A position for which the correct cube action is known which serves as a standard by which other similar positions may be judged. See post by Chuck Bower.