CODA now has a released page.

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mar
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Re: CODA now has a released page.

Post by mar »

jasper.sinclair wrote: Mon Jul 13, 2026 1:02 pm
Can you give an example of code directly copied from Stockfish or any other engine?
ChatGPT: "Yes. One clear example is Syzygy tablebase probing.

Ethereal's syzygy.c is not an original implementation—it wraps Pyrrhic, which is itself a fork of Fathom, Ronald de Man's GPL Syzygy probing library that originated from the Stockfish ecosystem. Ethereal explicitly includes and interfaces with Pyrrhic rather than reimplementing the probing logic from scratch.
do you realize that you spread slop-generated lies about Pyrrhic and Fathom?
it seems the holy slopmachine has mixed a random word salad for you :shock:

that you didn't fact-check the output is no excuse
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chrisw
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Re: CODA now has a released page.

Post by chrisw »

Ras wrote: Mon Jul 13, 2026 1:03 pm
chrisw wrote: Mon Jul 13, 2026 11:57 amIf an LLM, asked to code an idea in the context of the chess engine eco system (100 sources or more?) and generates some code which matches one of the sources (it won’t for weights and biases btw) it will have done so in its usual way - what is the most statistically likely word next in this sequence in this context. That’s not copying.
If it reproduces verbatim code passages, or verbatim translations from another programming language, this is copying. See the legal case I provided as example. Obviously, ChatGPT did not store the lyrics as a text file. But it did encode it sufficiently in the weights to reproduce it. Which isn't even astonishing because the models get larger and larger, and the risk of "overtraining" has been a known NN phenomenon for decades.
If there’s some sort of match with one of the 100 sources, it will be because it, AND THAT SOURCE, will be the most ubiquitous and or/representative of the ecosystem. Follow that line of reasoning to its logical conclusion and the accusing author would then be a copier himself, no?
Ideas and concepts are not copyrightable. Only a specific implementation - if the creative value is sufficient (e.g. some quicksort implementation will hardly count IMO). But since Andrew made the claim, the proof of burden is on him. The general claim that by the way how LLMs work, there can be copyright violations, that is correct - but the mere possibility is not enough. Let's see whether Andrew is willing to share some specific analysis, and whether it has merit.
Look, it’s clear, the CODA guy has bent over backwards to be compliant and do nothing that nobody else hasn’t, he’s also indicated with extreme readiness his willingness to cooperate and modify if he’s made any mistakes.
That doesn't change the fact clear attribution is a condition of pretty much all OSS licences. The problem with AI coding is that you can't even really know whether you have a problem. The provenance tracking gets lost through the LLM. You don't even know what exactly you need to comply with. This isn't specific to CODA. It's even more of a problem for companies who develop proprietary software and can accidentally pull in e.g. GPL code that no SBOM auditing is even aware of.

Right now, the legal debate largely focuses on the AI providers themselves, see the linked lawsuit. But there's a whole next rabbit hole waiting with the consumers of AI if they use the AI output.
AG has basically dropped the case with respect to the thirty or so GPL engines, CODA is a GPL release and it does attribute and it is honest about it.
AG continues on with two engines that are AGPL as opposed to GPL, the difference being requirement to provide source code if your engine is playable over the cloud (which CODA is via Lichess). Looks like CODA has not done that, has acknowledged it, said it's an oversight and will fix it. It's not exactly an earth shattering breach of a licence, and surely not enough for claims of theft, deceit and dishonour.
So where is his gripe? What has CODA done wrong? (getting out of wholesale copying charges is standard practice in computer chess, you just prefix the GPL announcement). What has CODA done that is different? Well, it's got a lot of Elo and authors who've spent time copying ideas, tuning and testing feels usurped. Well, okay, such is life, a process has arrived which automates human work. But it's neither theft, deceit nor dishonour.
chessica
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Re: CODA now has a released page.

Post by chessica »

[d]5k2/pp3N2/5K2/5B2/8/8/8/8 w - - 0 1
#9

Coda 0.9.0-nogit:
32/32 00:00,969 0 0 +288,00 Sf7-d6 Kf8-g8 Sd6xb7 Kg8-f8 Sb7-a5 Kf8-e8 Sa5-c6 Ke8-f8 Sc6xa7 Kf8-g8 Sa7-b5 Kg8-h8 Sb5-d6 Kh8-g8 Sd6-f7 Kg8-f8 Lf5-h7 Kf8-e8 Sf7-e5 Ke8-d8 Lh7-e4 Kd8-c7 Se5-c4 Kc7-d7 Kf6-f7 Kd7-d8 Le4-c2 Kd8-c7 Lc2-a4 Kc7-d8 La4-b5 Kd8-c7

[d]7k/5pp1/8/8/8/8/1K6/R7 w - - 0 1
#18

Coda 0.9.0-nogit:
19/19 00:00,391 0 0 +288,00 Kb2-b3 Kh8-h7 Ta1-a7 Kh7-g6 Kb3-c4 Kg6-f6 Kc4-d5 Kf6-g6 Kd5-e5 Kg6-g5 Ta7xf7 Kg5-g6 Tf7-a7 Kg6-h6 Ke5-f5 Kh6-h7 Ta7-a8 Kh7-h6 Ta8-h8+
smatovic
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Re: CODA now has a released page.

Post by smatovic »

So the solution is to use GPL v3 engines only as templates for a GPL v3 AI generated engine release, give credit, topic solved?

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jasper.sinclair
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Re: CODA now has a released page.

Post by jasper.sinclair »

mar wrote: Mon Jul 13, 2026 2:05 pm
jasper.sinclair wrote: Mon Jul 13, 2026 1:02 pm
Can you give an example of code directly copied from Stockfish or any other engine?
ChatGPT: "Yes. One clear example is Syzygy tablebase probing.

Ethereal's syzygy.c is not an original implementation—it wraps Pyrrhic, which is itself a fork of Fathom, Ronald de Man's GPL Syzygy probing library that originated from the Stockfish ecosystem. Ethereal explicitly includes and interfaces with Pyrrhic rather than reimplementing the probing logic from scratch.
do you realize that you spread slop-generated lies about Pyrrhic and Fathom?
it seems the holy slopmachine has mixed a random word salad for you :shock:

that you didn't fact-check the output is no excuse
This is what is found when trying to verify ChatGPT's answer concerning Pyrrhic and Fathom:
https://github.com/AndyGrant/Pyrrhic
"Pyrrhic is a partial cleanup of the Fathom library for probing up-tp 7-man Syzygy Tablebases. Pyrrhic attempts to reduce the burden on the global namespace introduced by Fathom, as well as provide a more robust API for decoding the results of function calls. Pyrrhic is kept fairly up-to date with changes as they are made to Stockfish's implementation, or the Fathom repository itself."

https://github.com/basil00/Fathom
"Credits
The Syzygy tablebases were created by Ronald de Man. Much of the probing code tbprobe.c is a modified version of Ronald's tbprobe.cpp for Stockfish (all Stockfish-specific code has been removed). The tbcore.c file is virtually unchanged from Ronald's original version.

License
(C) 2013-2015 Ronald de Man (original code) (C) 2015 basil (new modifications)

Ronald de Man's original code can be "redistributed and/or modified without restrictions"."
The "lies" are not evident, at least to me.

PS I guess "slop" has become the defacto "go to" denunciation for the anti AI group. Don't like AI? log in and call it slop! It's getting kinda old IMO. Perhaps you can come up with another descriptive derogatory term...
adamtwiss
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Re: CODA now has a released page.

Post by adamtwiss »

Thanks Andrew for your findings. On reading it, you're right on most fronts, and I'm not going to argue it. Coda started as a personal project and I leaned on a lot of open-source engines while building it. Some code/values from AGPL-licensed engines - Reckless and Viridithas - got in that aren't compatible with Coda's GPL licence. That's my mistake; I should have caught it.

I've started fixing it over the weekend - the Reckless king-bucket layout is already out, and I've pulled the 0.9.1 release I just did before reading this. I'm now going through everything derived from AGPL engines and removing or rewriting it, out in the open so it can be checked. I'd rather get this right than try and defend it. I will check other engines too, but my initial focus is the AGPL/GPLv3 mismatch.

I have considered making the repo private in the meantime, but I think I'd rather be transparent. I propose to stick a prominent note in the README, and get cracking with auditing and fixing it. This also allows others to post issues and see it.
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Ras
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Re: CODA now has a released page.

Post by Ras »

chrisw wrote: Mon Jul 13, 2026 2:13 pmWhat has CODA done wrong?
It's not only the two AGPL engines. That's only where the new licence (GPL) is actually incompatible if AG's analysis holds water. And the CODA code does contain references to Reckless and Viridithas. A lot of references in the comments. Which in itself isn't necssarily an issue because copying ideas and concepts is not against copyright. But it does invite a closer look.

The bigger issue is... it's *every other* engine as well. You cannot simply say thanks to an engine for some included code. Not only GPL, but also BSD, MIT etc licence require that the copyright notice that was in the original code and belonged to it must not be deleted. It must remain clear which code came from whom. But the problem with AI generated code is... you lose traceability. You don't even know whether other code is in. You cannot attribute code when you don't even know you may have it. But not attributing such code, if it can count as copying, forfeits the licence. Which then makes using that code a copyright infringement.

Not only with the AGPL engines. With potentially *every other* engine, or even random code, that Claude has been trained on. It's made even worse in that Claude can translate between programming languages, to a degree. That's even harder to spot.

That has nothing to do with bad will. The CODA author does take effort to stay in compliance. It's a general AI coding problem. Right now, AI coding is a risky decision.
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