CBG -- Clavierhaus BackGammon
The complete GNU Backgammon engine: play, coach, rollouts, career. Offline.
Version: 1.0.1
Added: 19-07-2026
Updated: 19-08-2026
Added: 19-07-2026
Updated: 19-08-2026
CBG Pro is the complete GNU Backgammon engine on Android -- and 1.0.0 is a major update that turns a strong backgammon app into the most capable analysis and training tool on the platform. It is not "based on" GNU Backgammon: it IS GNU Backgammon 1.08.003, vendored verbatim, with neural-net weights byte-identical to the desktop release. Every number on screen is the engine's own. Entirely offline -- the app does not even request the network permission. Free software, GPL-3.0, with reproducible builds verified by F-Droid's own pipeline against the developer's published binary.
New in the 1.0.0 major update:
* Regulation rollouts on your phone: 1296-trial, cubeful, variance-reduced, quasi-random -- the discipline desktop analysts use -- seed-reproducible, with the desktop-comparison harness published in the source repository.
* The Coach: every move judged against the engine -- best, fine-but-not-best (with what beat it), or flagged with the equity it cost. Tap any better alternative and watch it play out on the board against your own move. Cube actions judged too.
* Position set-up editor: build any position by hand, or paste a GNU BG ID, Match ID, or XGID from a forum or a book. Chequer rankings with dice on; double/take/drop equities with dice off.
* Your Personal Stats: match statistics computed by gnubg's own analysis -- error rates, luck, cube handling -- with every number labeled by what it is. No invented metrics.
* Your career, signed: finished matches enter a tamper-evident, cryptographically chained record. Your results, provable, in plain files you own.
* A tournament match clock (delay clock), offered upstream to the GNU Backgammon project itself.
The foundation, as always:
* Full matches at any length, seven strength levels from Beginner to Grandmaster.
* Complete cube play, Crawford, Jacoby, beavers, automatic doubles, and the canonical match-equity tables: Kazaross-XG2, Woolsey, Jacobs & Trice, Snowie, and the rest of gnubg's set.
* Save and review matches as standard SGF -- step through what you played, what the engine preferred, and what it cost. Files open unchanged in desktop GNU Backgammon and Backgammon Studio.
* Your matches and your career live in a folder you choose -- plain files, readable by anything, in twenty years too. Nothing is ever sent anywhere; there is no "anywhere" in this app.
Requires Android 12 or newer and a 64-bit ARM device.
New in the 1.0.0 major update:
* Regulation rollouts on your phone: 1296-trial, cubeful, variance-reduced, quasi-random -- the discipline desktop analysts use -- seed-reproducible, with the desktop-comparison harness published in the source repository.
* The Coach: every move judged against the engine -- best, fine-but-not-best (with what beat it), or flagged with the equity it cost. Tap any better alternative and watch it play out on the board against your own move. Cube actions judged too.
* Position set-up editor: build any position by hand, or paste a GNU BG ID, Match ID, or XGID from a forum or a book. Chequer rankings with dice on; double/take/drop equities with dice off.
* Your Personal Stats: match statistics computed by gnubg's own analysis -- error rates, luck, cube handling -- with every number labeled by what it is. No invented metrics.
* Your career, signed: finished matches enter a tamper-evident, cryptographically chained record. Your results, provable, in plain files you own.
* A tournament match clock (delay clock), offered upstream to the GNU Backgammon project itself.
The foundation, as always:
* Full matches at any length, seven strength levels from Beginner to Grandmaster.
* Complete cube play, Crawford, Jacoby, beavers, automatic doubles, and the canonical match-equity tables: Kazaross-XG2, Woolsey, Jacobs & Trice, Snowie, and the rest of gnubg's set.
* Save and review matches as standard SGF -- step through what you played, what the engine preferred, and what it cost. Files open unchanged in desktop GNU Backgammon and Backgammon Studio.
* Your matches and your career live in a folder you choose -- plain files, readable by anything, in twenty years too. Nothing is ever sent anywhere; there is no "anywhere" in this app.
Requires Android 12 or newer and a 64-bit ARM device.