Long vs short backgammon: what is the difference

In short: three differences

• Hitting. In long backgammon an opposing checker cannot be hit: the game is a race with positional blocking, not an exchange of blows. In the short game a lone checker — a blot — is exposed, and a hit sends it to the bar.
• Direction of travel. In the long game both players travel one shared ring in the same direction. In the short game they move toward each other, each to their own home board.
• The doubling cube. The long game has none at all. In the short game a player may double the stake at the start of their turn with a cube that multiplies the score from 2 up to 64.

Side by side

Eight parameters that genuinely separate the two games.

What long backgammon is

Long backgammon is played on a ring of 24 points where both players travel in the same direction and no checker can remove an opposing one from the board. White’s head sits on point 24 and Black’s on point 12 — exactly 12 points apart, diagonally. At the start each player holds all 15 of their checkers as a single stack on their own head, and nothing else is on the board.

The absence of hitting changes what a position costs. A point is closed by one checker rather than two, so a barrier of six consecutive closed points — a wall — costs exactly 6 checkers. The same barrier in the short game, where a closed point needs at least two checkers, would cost 12, twice as much.

The second peculiarity is the head rule: only one checker may leave the head per turn, except on the first turn with 3-3, 4-4 or 6-6, when two are allowed. The short game has no such restriction — no rulebook describes a separate rule about leaving the starting point. The full list is on the long backgammon rules page.

What short backgammon is

Short backgammon is the game most people mean by “backgammon”: the same 24-point board, different physics of movement. The players move toward each other to their own home boards and can hit a lone opposing checker, called a blot. The starting position is four groups rather than a single stack: according to the U.S. Backgammon Federation, two checkers on the 24-point, five on the 13-point, three on the 8-point and five on the 6-point — the same 15 per player.

A point counts as closed to the opponent only when two or more checkers of one colour stand on it. Bkgm.com puts it as “a checker may be moved only to an open point, one that is not occupied by two or more opposing checkers”. A hit checker goes to the bar and re-enters the game from the opponent’s home side, covering almost the whole route again.

The stake of a game is regulated by a doubling cube with faces from 2 to 64: a player offers the double at the start of their turn, before rolling, and the opponent either takes it or forfeits the game at the current stake. The rule is described in the USBGF beginner’s guide.

Telling them apart in ten seconds

1. Look for a separate strip at the side of the board holding checkers off the main points. That is the bar: if it exists, you are looking at short backgammon.
2. Look for a single opposing checker sitting alone among yours. In the long game you simply cannot put your checker there; in the short game you can, and it is a hit.
3. Look for an extra die marked 2 to 64 beside the two ordinary ones. If it is there — short backgammon. If not — long.

Which one to start with

There is no universal answer, only a practical guide. Long backgammon is simpler for a first encounter: with no bar, no doubling cube and no sudden loss of position, a game develops predictably.

Short backgammon has the longer competitive and research history. The first world championship was held in Las Vegas in 1967; according to the U.S. Backgammon Federation, it was organised by Alexis Obolensky. In 1995 Gerald Tesauro described TD-Gammon in Communications of the ACM, a neural network that reached the level of the strongest human players through self-play, and doubling thresholds are still being studied — a mathematical paper on them appeared on arXiv in October 2024.

The 24-point board and the 15 checkers per player are common to both games. The tactics, however, have to be learned separately: hitting changes almost everything.

What ProNardy plays, and why there is no cube

ProNardy is long backgammon: no hitting, no bar, one direction of travel for both players. The engine, the position evaluation and the Academy mistake detectors are built for this physics of the game, not for backgammon with a cube.

The absence of the doubling cube is a decision, not an omission. Tactical sources about backgammon drag the cube, match play and a foreign scoring scale along with them; those elements are kept out of the long-game core entirely, because mixing the physics of two games would break both. For the same reason the score here has four levels — Oin, Mars, Koks and Home Mars: the fourth was added deliberately, as the rarest event of all, rather than borrowed from the short game.

The features page covers playing the computer and reviewing games, and the tactics of a game without hitting are collected in long backgammon tactics.