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Open source chess developers warn about a commercial engine based on Stockfish

285 points| 1337shadow | 5 years ago |lichess.org | reply

130 comments

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[+] themodelplumber|5 years ago|reply
I'm glad the group spoke up. Free software or no, details matter, and in this case the details point to false claims and unethical behavior:

> It is sad to see claims of innovation where there has been none, and claims of improvement in an engine that is weaker than its open-source origins. It is also sad to see people appropriating the open-source work and effort of others and claiming it as their own.

> Everyone is permitted and encouraged to modify and improve code from Stockfish/Leela while giving credit; that is the intent of open-source software. Everyone is allowed to copy Stockfish/Leela and sell them, provided the terms of the Stockfish/Leela license are met. But don’t pretend that the product being sold is something it isn’t.

[+] cven714|5 years ago|reply
ChessBase is selling this Stockfish clone for €99.90. They have also disabled comments on all of their articles so far about Fat Fritz 2. Not a good look.

Related Article on Lichess (which is also open source) about Fat Fritz 2: https://lichess.org/blog/YCvy7xMAACIA8007/fat-fritz-2-is-a-r...

[+] autocorr|5 years ago|reply
Thanks for the link. That git diff is absurd: 9 changed files with 21 additions and 30 deletions[1]. It really is just Stockfish using different weights and changing the name... The fact this Albert Silver fella did the same with Leela Chess Zero two years ago is even worse, no remorse!

[1] https://github.com/official-stockfish/Stockfish/compare/550f...

[+] cambalache|5 years ago|reply
They are a sketchy company, from the over-zealousness to defend their "IP" to the price they demand for their yearly software, to the creepy vibe their articles about young female players have. So no sympathy from me, go stockfish.
[+] boarquantile|5 years ago|reply
ITT: People missing the point by making it about software licenses, when the real issue is lying about the product.

ChessBase could easily comply with any open source license by linking the full source code, including the method they used to generate NN weights (if they think the license applies here as well), in a footnote.

It would still be a scam, because their claims of superiority, originality ("almost from scratch"), and innovation (see the funny part about technology from Japan) are wrong, and purposely so.

[+] kazinator|5 years ago|reply
False claims of authorship (essentially plagiarism) are not entirely outside of the domain of copyright.

https://en.wikipedia.org/wiki/Attribution_(copyright)

For instance, let's look at the BSD license. It requires copyright notices in source code to be preserved. That means that it reserves the attribution right.

The original license required them in executable code; the two-clause version relaxes it; it doesn't demand any expression of attribution in the compiled code.

However, it does not appear to fully waive the attribution right; it requires the copyright notices and license clauses to remain in the source code. The compiled code is still the original author's copyright; nothing in the license says that it isn't.

If someone claims they developed it, it's infringement on the attribution copyright, even though they have the license-granted right to redistribute the code without making such deceptive claims.

IANAL, but if you're going to plagiarize, I suspect the safest bet is to pick something that has lapsed into the public domain, not something with copyrights and licenses in it.

[+] zelphirkalt|5 years ago|reply
What are these _open source_ licenses, which require you to link to the full source code? I might not have seen such a license yet. Usually "open source license" equates to MIT license and BSD licenses, which do not require you to link to the source code.
[+] vdddv|5 years ago|reply
Many commenters are missing that the issue is not that an Open Source project was repackaged as a commercial project, but that the open source origin has been hidden.
[+] 1337shadow|5 years ago|reply
> Many commenters are missing that the issue is not that an Open Source project was repackaged as a commercial project, but that the open source origin has been hidden.

That is not what Joost VandeVondele, current maintainer of the Stockfish project, posts:

> Recently, ChessBase has started distribution and sales of the Fat Fritz 2 chess engine. This chess engine is a Stockfish derivative, with a few lines of code modification (engine name, authors list and a few parameters), and a new set of NNUE net weights considered proprietary

> Selling Stockfish derivatives is possible with the GPLv3 license we grant, but not without requirements. In particular, the license states that if one redistributes a program derived from our work, the corresponding modifications of our sources and all information needed to build that program must be made available. Only after explicitly informing Albert Silver (the author of the net in Fat Fritz 2) of a license violation have matching C++ sources, but not the net weights, been made available. Obviously, we condemn the approach taken.

https://blog.stockfishchess.org/post/643239805544792064/stat...

[+] aaron695|5 years ago|reply
> but that the open source origin has been hidden.

What is the specific licensing issue here?

If this is about them not liking the product, fine, but don't dirty the open source ethos unless they are breaking the license. Part of the problem is the current HN headline perhaps.

[+] ufo|5 years ago|reply
This article is light on the details about this being a GPL license violation or not. The final paragraph also makes it sound like Stockfish is under a permissive license (only requiring attribution) when in fact it's licensed under the copyleft GPLv3.
[+] bonzini|5 years ago|reply
It was, but according to Wikipedia they sorted that out by moving the proprietary neural network out of the executable. If this is correct, it means that the source is available and the nature of the changes (including removing the original authors) should be visible.
[+] tromp|5 years ago|reply
ChessBase just posted a new article by A. Silver at

https://en.chessbase.com/post/how-a-neural-network-is-made

where the author tries to argue that doubling the neural network size in StockFish makes for an appreciable strength increase. However, only blitz results are shown. Looking at http://computerchess.org.uk/ccrl/4040/ we see Fat Fritz being only 2 ELO stronger than SF at blitz while losing out on longer time controls. This questionable tradeoff makes for a very poor excuse to charge $100 versus the free SF.

Public comments are once again blocked.

[+] yesenadam|5 years ago|reply
Some stories from ChessBase Chess News describing these products, roughly reverse chronological order:

https://en.chessbase.com/post/chess-and-artificial-intellige... ChessBase founder Frederic Friedel talks about Fat Fritz

https://en.chessbase.com/post/interview-with-albert-silver-h... 1 hr video interview with Silver about his "path to inventing the [Fat Fritz] 2.0 engine"

https://en.chessbase.com/post/fat-fritz-2-0-the-new-number-1 "Fat Fritz has revolutionised the world of chess engines."

https://en.chessbase.com/post/fat-fritz-2-best-of-both-world...

https://en.chessbase.com/post/fat-fritz-ingenious-without-st...

https://en.chessbase.com/post/fat-fritz-and-the-1200 has a section "What differentiates Fat Fritz from Leela?"

https://en.chessbase.com/post/fat-fritz-defeats-stockfish-ma...

https://en.chessbase.com/post/fat-fritz-what-on-earth-is-tha... 2019 - Albert Silver describes in detail how he made his "AlphaZero clone" Fat Fritz

[+] zucker42|5 years ago|reply
Have there been any court cases about whether neural net weights can be included under software licenses?
[+] xiphias2|5 years ago|reply
Copyright doesn't make a distinction between software and other text, but GPL3 probably does, and maybe allows changed weights without them being released (unlike software, where it's explicitly stated). I didn't read the license though.
[+] rbobby|5 years ago|reply
Are neural net weights code or configuration settings? Are email connectivity parameters code or configuration settings?

How would a judge distinguish the two?

[+] enjeyw|5 years ago|reply
I would have assumed that most people interested in chess engines are a pretty savvy and will do their research before buying anything, making the whole "create a sub-par ripoff" a rather ineffective strategy.
[+] dmurray|5 years ago|reply
Not really. Plenty of middling to world-class chess players aren't technically literate, but use chess engines for preparation. And Chessbase is the biggest name in chess software, though they've always had a slightly scummy approach to marketing.
[+] wobblyasp|5 years ago|reply
As long as the license allowed it, I'm not seeing the issue. Sure; it's a less-then-advertised product, but the world is full of those.

If people want to drop 100$ on something that doesn't work as well as the free alternative, more power to them. People do it everyday in the real world.

[+] AntonyGarand|5 years ago|reply
While this is something I would expect from a small random company, ChessBase is pretty big in the chess world.

For them to promote this "new" engine on their shop[0] feels wrong, I would expect them to meet certain quality threshold.

Lichess does mention this in the bottom of the post, which has the same feeling:

> Everyone is permitted and encouraged to modify and improve code from Stockfish/Leela while giving credit; that is the intent of open-source software. Everyone is allowed to copy Stockfish/Leela and sell them, provided the terms of the Stockfish/Leela license are met. But don’t pretend that the product being sold is something it isn’t.

[0] https://shop.chessbase.com/en/

[+] cbroadcast|5 years ago|reply
"It is sad to see claims of innovation where there has been none, and claims of improvement in an engine that is weaker than its open-source origins. It is also sad to see people appropriating the open-source work and effort of others and claiming it as their own."

The license allows to use the code, it does NOT allow taking the credit for things you did not do.

There's way too little credit given in open source in general, and I'm glad to see people fight back again (it was more customary to fight back before 2010).

[+] arnaudsm|5 years ago|reply
Just like dropshipping, it may be legal but is amoral to many people. And informing the general public is important.
[+] tudelo|5 years ago|reply
And I might be the only idiot here, but I tried to run stockfish from source and it was not an instant process. In addition, there isn't really a front end, you essentially end up with a CLI to input moves.

And for those who say, hey you, there are prebuilt binaries, just download them! Check out this message [1]

" The binaries at the top of the table are fastest, but may not support all CPUs. If you don't know which CPU you have, you can go down the list and pick the first binary that does not crash. "

Yeah okay, a pragmatic set of instructions that can't fail...

From this I think we could see why a product built on top of stockfish might make sense, even if the linked product might not do as such.

[1]https://stockfishchess.org/download/

[+] thom|5 years ago|reply
There is no way this is the outcome, but I’d love to live in the world where ChessBase get a proper commercial license to Stockfish to sell to people who don’t want to click three buttons to set it up themselves, in exchange for permanently opening up their database to the public.
[+] krick|5 years ago|reply
Can somebody explain to me how NN is used in Stockfish? I always assumed that some heuristic rules are used by Stockfish to evaluate the position, and I think this was actually the case not that long ago. So, does this mean heuristics are now being completely replaced by NN evaluations in Stockfish, all the prior work being completely thrown away?

In fact, isn't the position evaluation pretty much the only thing that makes Stockfish different from Leela, the rest being just some tweaks on top of traversing the decision tree? And if it now seems that NN is better at this after all, what is the purpose of having these 2 engines at all, shouldn't all the future work just be moving over to Leela?

[+] garrtt|5 years ago|reply
Clicking the link with lichess installed just opens the app. Long-press to open in a new tab.
[+] enneff|5 years ago|reply
FYI the lichess mobile apps have been abandoned in favour of the web view, if I recall correctly.
[+] pk_kinetic|5 years ago|reply
Copyright issues aside, you would think claims of innovation would be taken with a grain of salt until this engine competes with, and beats Stockfish and Leela at the TCEC (top computer engine championship).
[+] antirez|5 years ago|reply
Please read till the end:

Everyone is permitted and encouraged to modify and improve code from Stockfish/Leela while giving credit; that is the intent of open-source software. Everyone is allowed to copy Stockfish/Leela and sell them, provided the terms of the Stockfish/Leela license are met. But don’t pretend that the product being sold is something it isn’t.

[+] xiaodai|5 years ago|reply
so sad. I will not use chessbase for anything lichess it is
[+] mhh__|5 years ago|reply
Stockfish is under the GPL (IIRC) so I wouldn't be that worried.
[+] im3w1l|5 years ago|reply
GPL means you can put a version with proprietary modifications in the cloud and sell api access, without contributing anything back.
[+] jojobas|5 years ago|reply
Would it finally be the case where a GPL violator is taken to court?
[+] chongli|5 years ago|reply
Hopefully. I also hope this gets spread throughout the online chess community so that ChessBase gets their name dragged through the mud, as they rightfully should, for this blatant plagiarism.

Taking the work of others, erasing their name and inserting your own, is the kind of crap we expect from lousy cheaters in high school, not businesses who want to establish themselves in a market based on a centuries-old global institution.

[+] deeeeplearning|5 years ago|reply
> Everyone is allowed to copy Stockfish/Leela and sell them, provided the terms of the Stockfish/Leela license are met. But don’t pretend that the product being sold is something it isn’t.

What's the issue? Did OS contributors suddenly realize you can make money off software? They're upset at marketers doing marketing?

Don't understand the downvotes. If they violated the terms of the license or did something illegal then sue, otherwise they're just whinging.

[+] beermonster|5 years ago|reply
“It is sad to see claims of innovation where there has been none, and claims of improvement in an engine that is weaker than its open-source origins. It is also sad to see people appropriating the open-source work and effort of others and claiming it as their own.”

These seem to be their main gripes

[+] orwin|5 years ago|reply
It's a scam (it doesn't even use the best version of stockfish, so much for "the best chess engine available").

Moreover, it infringe GPL. I would love if a country started enforcing GPL with huge fines. Company-destroying fines.

[+] MaxBarraclough|5 years ago|reply
If a seller only gets sales because of the ignorance of their customers, it's a rip off. I'd be annoyed if my work was being used to rip people off, even if no licence terms or laws were being broken.
[+] cycomanic|5 years ago|reply
Apart from the question of legality of removing copyright notices/changing authorship (which is definitely a copyright violation in some jurisdictions), there is more than just legality.

One can (and most people do) condemn some actions even if they are technically legal.

[+] enneff|5 years ago|reply
They’re just letting the community know that they shouldn’t fall for the scam.