Match play
Gammons, the doubling cube, and the rules that turn a string of games into a match.
Matches and stakes
A match is played to a target score — first to 3, 5, 7, and so on. You play game after game, adding the points won to a running total, until someone reaches the target. A "single game" here is simply a match to 1.
Each game is worth its base value (1 point) multiplied by two things: the result type and the doubling cube.
Gammons and backgammons
The win type sets the base multiplier:
- Single — 1 point.
- Gammon — 2 points (loser bore off no checkers).
- Backgammon — 3 points (loser bore off none and still has a checker in the winner's home board or on the bar).
Whatever this base, the doubling cube then multiplies it.
The doubling cube
The cube is a six-sided die marked 2, 4, 8, 16, 32, 64. It tracks the current stake. At the start of a game it sits in the middle at 1 and belongs to nobody.
Before rolling on your turn, you may offer to double the stake. Your opponent then chooses:
- Take — accept. The stake doubles, and they now own the cube (only they can make the next double).
- Drop — decline. The game ends immediately and they lose the current stake (before the double).
Ownership matters: once you double and your opponent takes, you can't double again until they've doubled you back. A well-timed double — or a disciplined drop — wins matches. The rough guideline: take if you'll win more than 25% of the time, double when you're a clear favourite but the game could still swing.
Beavers (money play)
In money games, a player who is doubled and believes they're actually the favourite may beaver: accept and immediately redouble to the next level while keeping ownership of the cube. Beavers don't apply in match play.
The Crawford rule
When one player gets to within a single point of winning the match (they are "1-away"), the very next game is the Crawford game, and the doubling cube is disabled for that one game. This stops the trailing player from doubling immediately out of desperation when they have nothing to lose.
Post-Crawford
After the Crawford game, the cube is live again. Now the trailing player will often double at the first opportunity — there's no reason not to, since they must win anyway. Because of this, the leader frequently faces a free drop: in some score situations they can decline a double at no real cost, which is a genuine skill of post-Crawford play.
The Jacoby rule (money play)
In money games, the Jacoby rule says gammons and backgammons count only as a single game unless the cube has been turned at least once. This discourages dragging out a game purely to play for a gammon, and speeds money sessions along. Like beavers, it's a money-play convention — match play scores gammons and backgammons in full regardless.
Backgammon with Friends models every game as a match (a single game is just a match to 1), so the cube, Crawford, post-Crawford, and Jacoby all run through the same engine whether you're playing one game or a long match.