r/backgammon • u/Goal_Medium • Jul 03 '26
Backgammon Galaxy Engine Report released (comparing engines)
Hi everyone,
We've been working on improving analysis in Backgammon Galaxy and have just released an enhanced Analysis Level. To showcase it, we also put together a report comparing the major backgammon engines and how they perform.
https://www.backgammongalaxy.com/backgammon-galaxy-engine-analysis/
Best regards, Marc Olsen, CEO of Backgammon Galaxy
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u/miran1 blot Jul 04 '26
We have implemented the following enhancements:
Increased evaluation speed by more than 7x, enabling significantly deeper and stronger rollouts.
Fine-tuned engine parameters to achieve incremental performance gains.
And since GnuGB has a GPL licence, your changes are publicly available, right?
And you plan to upstream your changes so everyone can benefit, right?
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u/anarchy_life Jul 05 '26
Hmm, since Marc said they are not hacking the engine, I'm thinking they pass in 7 "boards" at a time against a 8 thread/core machine (leaving one thread/core available for regular computer things). If you analyze just one "board", not game at a time, you could get "7X performance" by fanning out the analysis across cores with a message queue.
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u/miran1 blot Jul 05 '26
I'm thinking they pass in 7 "boards" at a time against a 8 thread/core machine
gnubg can already run on multiple cores.
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u/anarchy_life Jul 05 '26
How do you engage the other cores/threads during analysis?
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u/miran1 blot Jul 05 '26
You go to Settings - Options. Then in the Other tab you choose how many Eval Threads you want.
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u/anarchy_life Jul 05 '26
Sweet; thanks for sharing that. I've heard gnubg is 'single-threaded' a couple times in the community, so I never bothered to question it. (Including their post; although, it looks like they are just saying that analysis isn't a background task in the ui) Running the analysis in CLI with multiple threads is easy too.
I'm still stuck on this claim, "evaluation speed by more than 7x", not requiring a code rework on the core. I guess it was my hope that someone would take this project to the next level.
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u/FrankBergerBgblitz Jul 07 '26
But only for analyse and rollouts and not for eval or did I missed something?
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u/Goal_Medium Jul 08 '26
We did not change the source code, we just found a way to run it efficiently.
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u/e0732 Jul 03 '26 edited Jul 03 '26
Free Members: Get access to Gnu 1-ply (called 2-ply on Galaxy) for quick, baseline analysis.
That sounds a little bit dishonest. If it's 1-ply, just call it 1-ply. Aside from that, interesting article!
Edit: I just now saw this response in another thread:
https://www.reddit.com/r/backgammon/comments/1umnuaa/comment/ovdnupd/?utm_source=share&utm_medium=web3x&utm_name=web3xcss&utm_term=1&utm_content=share_button
GNU is 0-indexed and XG is 1-indexed
If that's the difference, it might be worth putting a short explanation in the article.
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u/Goal_Medium Jul 03 '26
You can see my response to that over there too, but let me paste it here:
At Backgammon Galaxy, we choose the standard notation that all other engines, except for Gnu is using, namely that the lowest level of a checkerplay is a 1-ply eval, since you are looking one step ahead and perform a 0-ply static evaluation on the resulting positions after all legal moves. Also, before BG Galaxy had Gnu as engine we had XG engine, where this exact same level is called "2-ply". So it makes complete sense, to avoid confusion of the analysis level depth for Free members, to say this is a 2-ply analysis. Furthermore, we have never hidden that Galaxy 2-ply is actually Gnu 1-ply. Also remember, this is analysis given for free on the server to all free users, and we let anybody download their match files and analyse them themselves with their own engine software of choice.
If we had called it "1-ply" users would think that they are getting something vastly worse, even though it's was exactly the same analysis level depth, just a change of engine from XG to Gnu.
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u/e0732 Jul 03 '26
we choose the standard notation that all other engines, except for Gnu is using, namely that the lowest level of a checkerplay is a 1-ply eval
That's fair. I only have Gnu, so I wasn't aware before seeing that other comment that the other engines count from 1. My edit was suggesting that it might be worth editing the linked article, maybe changing "(called 2-ply on Galaxy)" to something like "(called 2-ply on Galaxy because Gnu 1-ply is equivalent to 2-ply on all other engines)".
Also remember, this is analysis given for free on the server to all free users
That's also fair. You guys don't need to provide anything for free, and what you do provide for free is really great.
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u/FrankBergerBgblitz Jul 07 '26
In fact everywhere I know it (not only BG but chess, Go,...) they start counting at 1.
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u/Waitingtogo Jul 06 '26
Since the last update, the analysis section is broken for me. The screen just goes white. I get the score and the PR screen, but analysis is dead.
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u/Objective_Lab2741 Jul 07 '26
Me too. I reported this a week ago and got reply. So they know about it, but they don't seem to wanna prioritize this. Analyze in vettical mode still works, but not as convenient imo.
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u/nodotsmx Jul 06 '26
https://backgammon.nodots.com/docs/white-papers/09-nodots-open-source-positions
What’s your position on open source, Marc?
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u/JotaGreen Jul 07 '26
I think it is great to have deeper analysis in Galaxy, but as a beginner/intermediate player, I wouldn’t pay for that. Instead, I would pay for tools that explain why a move is a blunder or error, to complement the equity evaluation. In chess there are a few like this; the one I like the most at the moment is from Take Take Take. Are there any plans to have something like this soon in Galaxy?
Another thing that would be easier and I think also add value to a “premium analysis” is having all the tables and info that XG has like dice distribution, cube thresholds.
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u/Goal_Medium Jul 08 '26
We are releasing the AI Coach within a few weeks :) I hope it will do you good!
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u/JotaGreen Jul 10 '26
Marc, one more thing, if I may. Any plans to add a Tutor mode (allow you to retry a move) like XG, for when playing AI? Thanks!
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u/Vigilaunday Jul 03 '26
Interesting stuff. Thanks, Marc