Doubling cube in tournaments

[MarkSteere]

Is the doubling cube ever used in tournaments, or is it just used in two-player matches?

[euklid314]

I just looked at the available tournaments. The tournament series "Quarterly Swiss League" is played via 5-point-matches with doubling cube.

The next of these tournaments (Q4-2025) will start on 01.10.2025.

[edit: I know you are a game designer with interest in adding a doubling cube in one of your games. If this is your main interest you might try out playing BG arena which has 3-point matches with doubling cube in the current season. Or challenge me for a turn-based 7-point match. The most "strange" rule for doubling in Backgammon is the Crawford rule which disallows doubling in certain situations.
Please note that there are some (non-gamebreaking) bugs in the handling of the doubling cube in the current BG implementation. E.g., if the current value of the cube is sufficient to win the whole match the cube is dead for you and you are not allowed to double. Here on BGA it is possible, however.]

[MarkSteere]

Thanks for the information. Follow up question: Regardless of how many points you win the match by, it only counts for 1 point in the tournament, right?

I googled that doubling cube rule. Google AI is not tremendously reliable, but here's what it had to say...

"Yes, you can double again even if the current cube value is sufficient to win the match, as long as you have cube ownership. This is known as a redouble, and if the opponent drops, they concede the points based on the last stake, but if they take, the cube shifts to their ownership at twice the value. There is no limit to the number of times a double or redouble can be offered in a game, but a special rule called the Crawford Rule may apply to prevent doubling in the game immediately before the match ends."

I'll play Backgammon with you in real time if you want to arrange a time.

I ended up adding a doubling cube, up to 21 point matches, and the Crawford rule to Jokerball. If anyone is interested to play, please let me know and I will challenge you. It's still in alpha.

https://www.marksteeregames.com/Jokerball_rules.pdf

[euklid314]

Yes, you are correct. In Backgammon tournaments a win is a win - independent of the score. If you play a 9-point match within a tournament, a 9:0-win is equal to a 9:8 win in every aspect.

And... if the score is, say, 6:2 and you win 4 points (e.g. via a doubled gammon or a single win with cube on 4) then the final score will be noted as 9:2, not 10:2. This is another "wrong" implementation on BGA (but again not game-breaking at all, just unusual if you are accustomed to Backgammon nomenclature)

There are different tournament systems (KO, round robin, or last man standing tournaments were every player is eliminated after their, say third, loss) but they generally have in common that each round is a 2 vs. 2 duel, a match to X points with doubling cube (X odd).

[Scharlach]

I googled that doubling cube rule. Google AI is not tremendously reliable, but here's what it had to say...

"Yes, you can double again even if the current cube value is sufficient to win the match, as long as you have cube ownership. This is known as a redouble, and if the opponent drops, they concede the points based on the last stake, but if they take, the cube shifts to their ownership at twice the value. There is no limit to the number of times a double or redouble can be offered in a game, but a special rule called the Crawford Rule may apply to prevent doubling in the game immediately before the match ends."

I wouldn't trust a neural network as a rules reference.

Tournament rules at Backgammon Galore imply that such doubling is indeed possible:

A match ends as soon as one player's score meets or exceeds the agreed upon match-length as written on the draw sheet. Neither player may concede the match prior to this occurrence. Note that regardless of score, a match may not end on a dropped cube.
Example: If a player is leading 2-away/4-away and the leader holds a 2 cube and redoubles, if the other player drops the match does not end. Instead, the player is alerted of his error, accepts the double, and completes the game.

On the other hand, US Backgammon Federation rules disallow it as euklid said:

The cube is dead for a player who would win the match by winning the game at the current cube level. Any cube action during the Crawford game or with a dead cube is void.

[euklid314]

Fascinating! I have never heard of rules like the Backgammon Galore rules. They are from 2012 - are they still in use in RL or online tournaments?

I have chatted with Mark via PM and told him that my source is from the World Backgammon Federation (https://wbgf.info). Their tournament rules are 19 pages in total and rule 4.4 handles dead cubes (in an identical manner to the USBGF).

[MarkSteere]

From the Jokerball wiki, now including a reference to USBGF and WBGF:

The "dead cube" rule (as defined by USBGF and WBGF): If the player owning the doubling cube could win the match by winning the current game, then she has no reason to offer a double, and is not allowed to offer a double.

[Scharlach]

I have no idea if the BKGM rules are in use anywhere. It suprised me too to find this variant.