English Chess Forum

Is anybody able to explain what this controversy is about without using technical language?

And without getting Carl into trouble!

Chessbase are selling chess programs that are very, very closely based on products written by other people and available for free.

Thanks. I assumed that was roughly what it was about: I wasn't sure (and I appreciate why it might be difficult to spell out) whether there was potentially a legal aspect here, or whether because it's open source, it might just be up to the customer to know better.

I don't think anyone is alleging that chessbase have done anything that is against the law. But I can empathise with the people who have put huge effort into Leela and Stockfish and are annoyed that their work is being exploited for commercial purposes.

Probably also a moment to reflect that anyone who has ever bought a commercial chess database should consider making a donation to TWIC. The is often a remarkable correlation between the things Mark publishes for free and the things others sell.

Basically they took open source software like Leela, changed the author name and a couple parameters, and said they created the engine while selling it at a profit (not sure whether the Leela and Stockfish licences allow commercial use )

In short, very predatory and scummy behaviour.

I think the answer to that lies in how difficult its become to both market and sell chess software. If its become so hard that the only way to do it is to try and emulate Alphazero then that should explain why all this has come about. It feels more like an act of desperation rather than an example of development in software itself. What chess.com and lichess offer is enough for me because, ultimately its more down to how you use them rather than what they can do themselves, something which is all too often overlooked.

Wadih Khoury wrote: ↑

Sat Feb 20, 2021 9:58 am

Basically they took open source software like Leela, changed the author name and a couple parameters, and said they created the engine while selling it at a profit (not sure whether the Leela and Stockfish licences allow commercial use )

In short, very predatory and scummy behaviour.

Agreed. In desperate times people undertake desperate measures. That's what it smells of to me.

"Probably also a moment to reflect that anyone who has ever bought a commercial chess database should consider making a donation to TWIC. The is often a remarkable correlation between the things Mark publishes for free and the things others sell."

A friend of mine started putting annotations like "A real Clint Eastwood move" in games and then looked at new Chessbase databases only to find the various annotations appeared in the games, with "Chessbase" as annotator!

Paul Cooksey wrote: ↑

Sat Feb 20, 2021 9:56 am

I don't think anyone is alleging that chessbase have done anything that is against the law. But I can empathise with the people who have put huge effort into Leela and Stockfish and are annoyed that their work is being exploited for commercial purposes.

Probably also a moment to reflect that anyone who has ever bought a commercial chess database should consider making a donation to TWIC. The is often a remarkable correlation between the things Mark publishes for free and the things others sell.

The full TWIC database is available from Mark for a reasonable donation, which is better than buying a commercial database I think

The engines that come with lichess and chess.com seem perfectly adequate to me.

JustinHorton wrote: ↑

Sat Feb 20, 2021 9:50 am

I wasn't sure (and I appreciate why it might be difficult to spell out) whether there was potentially a legal aspect here, or whether because it's open source, it might just be up to the customer to know better.

The answer is yes, there is a legal aspect. If it's a copy of Stockfish with modifications it's subject to the GNU General Public License v3.0 that the developers of Stockfish have applied.

That permits copying and reuse, but requires, for example:

• It must be disclosed as being based on Stockfish
• It must be subject to the GNU General Public License v3.0
• The source code must be made available

JustinHorton wrote: ↑

Sat Feb 20, 2021 9:50 am

Thanks. I assumed that was roughly what it was about: I wasn't sure (and I appreciate why it might be difficult to spell out) whether there was potentially a legal aspect here, or whether because it's open source, it might just be up to the customer to know better.

Not quite. If the software is covered by a specific licence (eg Gnu Public Licence) it is a requirement to identify where the program came from. The principle is that if you are going to use the work of others you a) acknowledge their work and b) 'pay it forward' by making your work available to others. NB There is no restriction on charging for such software (hence the expression 'free as in speech, not free as in beer') but you need to make it clear to the customer what you are really charging them for.
A non-chess example (with a link to chess) concerned the 'Samba' filesharing software developed by Dr Andrew Tridgell (the author of the Knightcap chess engine). A US company simply took the source code, changed the authors name and a few other things, and sold it for $50,000 a licence, passing it off as their own. The lawyers were called, and the sales soon stopped.

[Edit: Ian got in just ahead of me!]

There's also a statement from Stockfish.

One thing I'm not clear about is whether Chessbase has yet made available *all* of the source code / source data required by the GPL. It appears from the Stockfish statement that no source was made available at first and then, when a source was released, it wasn't everything. [edit: I'm not quite sure whether the part that was omitted is required by the GPL or not.]

The Lichess statement also states that FF2 was advertised as being the strongest engine available and in support of this presented results which were against not the version of Stockfish on which FF2 was based but an earlier version. If true that seems off, especially if, as Lichess claim, the version of Stockfish on which FF2 is based is actually stronger than FF2 - a somewhat strange situation [edit] in that the original is stronger than the derivative[/edit]!

Didn't Rybka get into some sort of similar controversy

"Allegations have surfaced that Rybka 1.0 beta and other versions of Rybka are derivatives of Fruit 2.1 and Crafty."
www.chessprogramming.org/Rybka_Controversy

Angus French wrote: ↑

Sat Feb 20, 2021 12:52 pm

One thing I'm not clear about is whether Chessbase has yet made available *all* of the source code / source data required by the GPL. It appears from the Stockfish statement that no source was made available at first and then, when a source was released, it wasn't everything. [edit: I'm not quite sure whether the part that was omitted is required by the GPL or not.]

ChessBase say (on the Description tab)

Fat Fritz 2 is an original neural network that is powered by a modified version of Stockfish. Stockfish is an open-source project licensed through the GPL v3 with all due rights. The source code of Stockfish and the modifications for Fat Fritz 2 can be found on Github.

It's in the Stockfish repository on github.

There's 50 pages of discussion on Fat Fritz 2 on TalkChess.com which includes the claim that the neural net published on github is different from the one ChessBase are selling.