Fat Fritz 2

[Collingwood]

Stockfish clone, likely worse, likely not special in training. If you want to spend money in the computer chess world, buy a copy of Komodo so that you are at least contributing to the continued progression of computer chess, not to the pockets of someone who has made no efforts or advancements in the field aside from going up the tax brackets. Perhaps something soon will appear worth buying...

A useless clone, taking advantage of the work of unpaid volunteers that didn't put a price tag for advancing computer chess, trying to get money from people that don't know better.

Legal but shady.

The scheme only work with deceptive marketing (using SF-dev for their clone, comparing performance to SF12...). It's not an outright scam, but it's not much better.

A boycott of Chessbase may be in order.

[dkappe]

Rybka, Houdini and now this one!
The question is:
Should I delete the links to Chessbase from the webpage?

Other products are really good (example: Chessbase database).

Possibly. At least add a message publicising what Chessbase has done here.

What has it done?

[AndrewGrant]

Rybka, Houdini and now this one!
The question is:
Should I delete the links to Chessbase from the webpage?

Other products are really good (example: Chessbase database).

Possibly. At least add a message publicising what Chessbase has done here.

What has it done?

Facilitated the sale of a product, in violation of the rights of another party, in regards to Houdini.

[Sesse]

The net and engine might be covered by different licenses, as is the case with Stockfish (GPLv3) and the stockfish networks (creative commons).

If they are, and the licenses are not compatible (which very roughly means that one is a subset of the other), you simply cannot combine them into one work and distribute (“convey”, as the GPLv3 says) the result. “You may convey a work based on the Program […] provided that you also meet all of these conditions: […] You must license the entire work, as a whole, under this License to anyone who comes into possession of a copy. This License will therefore apply, along with any applicable section 7 additional terms, to the whole of the work, and all its parts, regardless of how they are packaged.”

So if you combine Stockfish with a NNUE network, and distribute the result (whether you sell it or just offer it for download), the result becomes GPLv3, and thus, the network also has to be GPLv3 (or something more permissive). IOW, if you bought Fat Fritz 2, feel free to extract the network and share it with everyone as you see fit.

[dkappe]

The net and engine might be covered by different licenses, as is the case with Stockfish (GPLv3) and the stockfish networks (creative commons).

If they are, and the licenses are not compatible (which very roughly means that one is a subset of the other), you simply cannot combine them into one work and distribute (“convey”, as the GPLv3 says) the result. “You may convey a work based on the Program […] provided that you also meet all of these conditions: […] You must license the entire work, as a whole, under this License to anyone who comes into possession of a copy. This License will therefore apply, along with any applicable section 7 additional terms, to the whole of the work, and all its parts, regardless of how they are packaged.”

So if you combine Stockfish with a NNUE network, and distribute the result (whether you sell it or just offer it for download), the result becomes GPLv3, and thus, the network also has to be GPLv3 (or something more permissive). IOW, if you bought Fat Fritz 2, feel free to extract the network and share it with everyone as you see fit.

That’s not how copyright works. The whole work doesn’t magically become GPL just because you are in violation of the license. For example, if someone distributes one of my nets embedded in a GPLv3 licensed engine, that doesn’t mean I give up my copyright.

[AndrewGrant]

The net and engine might be covered by different licenses, as is the case with Stockfish (GPLv3) and the stockfish networks (creative commons).

If they are, and the licenses are not compatible (which very roughly means that one is a subset of the other), you simply cannot combine them into one work and distribute (“convey”, as the GPLv3 says) the result. “You may convey a work based on the Program […] provided that you also meet all of these conditions: […] You must license the entire work, as a whole, under this License to anyone who comes into possession of a copy. This License will therefore apply, along with any applicable section 7 additional terms, to the whole of the work, and all its parts, regardless of how they are packaged.”

So if you combine Stockfish with a NNUE network, and distribute the result (whether you sell it or just offer it for download), the result becomes GPLv3, and thus, the network also has to be GPLv3 (or something more permissive). IOW, if you bought Fat Fritz 2, feel free to extract the network and share it with everyone as you see fit.

That’s not how copyright works. The whole work doesn’t magically become GPL just because you are in violation of the license. For example, if someone distributes one of my nets embedded in a GPLv3 licensed engine, that doesn’t mean I give up my copyright.

I hate to say it, but I do agree with Dkappe. Whether the data is compiled in or not is mostly meaningless. UnoriginalFritz2 could just as easily obtain the same result by 1) Providing for free and the source for a Stockfish fork that has a constant changed, and 2) Selling you a weights file and telling you to use the Stockfish options to select that file.

[Sesse]

That’s not how copyright works. The whole work doesn’t magically become GPL just because you are in violation of the license. For example, if someone distributes one of my nets embedded in a GPLv3 licensed engine, that doesn’t mean I give up my copyright.

Actually that is how copyright works, only indirectly.

If someone distributes one of your nets embedded in a GPLv3-licensed engine, they are in violation of GPLv3, and the combination becomes undistributable (for everyone, including for them). But if they owned the copyright to the network, they had committed estoppel and implicitly licensed the network under GPLv3.

Or in different terms: They distributed (even sold!) a product well knowing that one of its parts was GPLv3, so the only reasonable interpretation is that they licensed the whole under GPLv3. You cannot after-the-fact come and say “oh, no, we sold you this product, but we chose not to grant you the rights we knew we had to grant you to be allowed to make that sale”.

[dkappe]

I hate to say it, but I do agree with Dkappe. Whether the data is compiled in or not is mostly meaningless. UnoriginalFritz2 could just as easily obtain the same result by 1) Providing for free and the source for a Stockfish fork that has a constant changed, and 2) Selling you a weights file and telling you to use the Stockfish options to select that file.

You show good judgement and taste agreeing with me.

My point was more about what happens if you are in violation of the GPLv3, that at the very least you have to stop being in violation. Putting the whole work under the GPL would be one option, but you may not have rights to the offending parts. In that case you might replace or rewrite those parts, or just stop distributing the whole thing.

[Sesse]

I hate to say it, but I do agree with Dkappe. Whether the data is compiled in or not is mostly meaningless.

This is true, and the license is clear on that (“however packaged”). What matters is that they are selling a combined work.

UnoriginalFritz2 could just as easily obtain the same result by 1) Providing for free and the source for a Stockfish fork that has a constant changed, and 2) Selling you a weights file and telling you to use the Stockfish options to select that file.

This is also true, but it's not what they did. Why do you think that is?

[AndrewGrant]

I hate to say it, but I do agree with Dkappe. Whether the data is compiled in or not is mostly meaningless.

This is true, and the license is clear on that (“however packaged”). What matters is that they are selling a combined work.

UnoriginalFritz2 could just as easily obtain the same result by 1) Providing for free and the source for a Stockfish fork that has a constant changed, and 2) Selling you a weights file and telling you to use the Stockfish options to select that file.

This is also true, but it's not what they did. Why do you think that is?

Oh don't get me wrong -- I think what they've done is very intentional. Last time around they made zero efforts to indicate the true nature of "their" product, and to inform users of the rights they have. I think selling a repackaged Stockfish is lazy, boring, unoriginal, and a downright scam targeting low information patrons.