Our lawsuit against ChessBase

1. Lost profits due to the infringement.

2. The profits the infringer made from the infringement.

3. The amount the infringer would have had to pay to license the work to use the way they did it if they had requested such a license from the copyright owner.

The first one would likely not apply to something that is solely licensed under GPL, but the other two might, especially #2.

I'm curious how #3 is determined.

There is something similar in the US for patent infringement damages. That involves the court trying to determine what would have happened in a hypothetical negotiation if the patent owner had been willing to license the patent and the infringer had wanted to license the patent.

That can work because usually with patents you can compare to other patent in the same or related field that are about as valuable and have been licensed out. I don't think that there are a lot of open source world class chess engines that are dual licensed for proprietary use that a court could use for comparison.

[1] https://www.lexology.com/library/detail.aspx?g=cef58d76-21a2...

They are normally from $750-30000 per work infringed.

The lower limit can be lowered to $200 if the defendant can prove that they were an innocent infringer (they were not aware and had no reason to believe they were infringing). The defendant has the burden of proof for this.

The upper limit can be raised to $150000 if the infringement is "willful". The statute does not define "willful". Courts have taken it to mean reckless disregard. The defendant knew they were infringing and did it anyway.

The jury decides where in the range you end up, and they certainly might take into account the magnitude of your infringement so 10000 downloads might cost you more than 1000 by convincing the jury to choose somewhere high from the range, but the cap on the total will be $30k (or $150k if it was willful).

Note that this means that willfully distributing 10000000 copies of one movies is going to be a lot better for the defendant than distributing a single copy each of 300 different movies, if the plaintiff elects to ask for statutory damages.

The 10000000 copies of one movie is just one work infringed, so you are looking at $150000 worst case.

The single copy each of 300 movies is 300 works infringed, so best case (assuming you are not an innocent infringer) is the minimal amount of statutory damages per work, $750, times 300 works = $225000.

(But remember that the plaintiff gets to choose between statutory damages and actual damages. If you've distribute 10000000 copies of their movie, they'll probably go for actual damages which could be considerably more than $150000!)

1. ChessBase was in violation of the GPL, but then cured the violation by releasing code (https://stockfishchess.org/blog/2021/statement-on-fat-fritz-...). But the post claims they refused to release the weights.

2. But the weights are already being released with the program they're selling. Otherwise, how would the program run? Why would they refuse, when they already distribute the weights with every copy of the program? I thought maybe Fat Fritz 2 was a cloud-hosted solution (weights aren't provided locally), but https://en.chessbase.com/post/running-leela-and-fat-fritz-on... seems to indicate it can run on a laptop with a GPU.

I suspect Stockfish may be trying to argue that whatever code was used to generate the weights is also covered under GPL, and that ChessBase is in violation because they refuse to release this code. I hope they don't try that argument, because it's certainly not true; you're free to train a chess engine however you want, insert the weights into a GPL'd program, and then are under no obligation to release the code to train the weights.

3. Setting aside the question of copyright entirely, it's unclear that Fat Fritz 2 is actually worse. Stockfish references https://www.sp-cc.de/ as an independent rating system, but if you look at the detail view (https://www.sp-cc.de/files/programs.dat) Fat Fritz 2 only seems to be compared to Stockfish 13 (210218) and not the latest versions of Stockfish.

I'm on Stockfish's side here, because I suspect ChessBase simply duplicated StockFish's training methodology and tried to pass it off as their own. (The engine's performance seems almost identical.) But I hope Stockfish has an airtight case for court. It'd be a bad idea to hinge the GPL violation on "they refused to release the neural net weight training code."

https://sfconservancy.org/copyleft-compliance/enforcement-st... https://sfconservancy.org/copyleft-compliance/firmware-liber...

Note that it’s legal to sell stockfish as long as you’re compliant with GPLv3. ChessBase seems to be compliant.

Stockfish argues that ChessBase isn’t compliant because they refuse to release the weights. But this makes no sense; the weights are distributed with every copy of Fat Fritz 2. (Otherwise, how would the program run? It’s not cloud-based, as far as I can tell.)

Stockfish may be trying to say “you must open source any training code used to make the weights.” But this claim falls flat; you could use this same argument to say that any GPLv3 codebase must be fully open source in order to sell it, including all DLLs used by the program.

Stockfish seems to be saying that they have grounds for lawsuit because they have terminated ChessBase’s license. But GPLv3 doesn’t give you the ability to terminate a license arbitrarily; it requires you meet some specific criteria, and it’s unclear that ChessBase meets it.

I think it’s lame that ChessBase sold stockfish for $80. But that’s different than being illegal, and we should worry about the precedents set here.