Sensational! Y.Ossipov talking about STRELKA

[Ryan Benitez]

Some of the bugs in the 2 engines are inherited from Fruit actually. Fruit has very few bugs compared to other engines but some of the hack fixed bugs pop up when trying to cover your roots. I don't know how much if any GPL code either engine has, I am very open to the possibility that neither engine ever technically had any Fruits code in it at all. It is possible to rewrite Fruits algorithms in your own code and inherit the same bugs. Given the language barrier I don't think it is far to judge Osipov at this point. Keep in mind that people have very little to gain from making illegal clones of GPL engines and a lot to lose. The GPL gives programmers a lot of freedom to contribute to a project in a positive way. As someone who has not read this forum in several months it is disappointing to come back to see such a witch hunt for clones and so little positive computer chess talk.

[George Tsavdaris]

Why shouldn’t Rajlich discover code of Rybka to experts (as Osipov did) to prove that he didn't copy parts of Fruit?

This works in the opposite way. You are innocent until proven guilty.
And not guilty until proven innocent.
So V.Rajlich has every right to do whatever he wants!

And we can't support he did copy parts of Fruit because we don't have any evidence. Unless we find evidence we can only say that he didn't copy parts of Fruit.

Also the fact that Y.Osipov revealed his code does not mean that another programmer should do the same.

[Andrej Sidorov]

So V.Rajlich has every right to do whatever he wants! And we can't support he did copy parts of Fruit because we don't have any evidence. Unless we find evidence we can only say that he didn't copy parts of Fruit.

There was evidences, if you read this topic.
See http://64.68.157.89/forum/viewtopic.php?p=130102#130102

[George Tsavdaris]

So V.Rajlich has every right to do whatever he wants! And we can't support he did copy parts of Fruit because we don't have any evidence. Unless we find evidence we can only say that he didn't copy parts of Fruit.

There was evidences, if you read this topic.

There it says:

For me all this looks like there is something taken from Fruit code, but it is also possible that Fruit was the example on how to do the engineoutput.

[Dann Corbit]

Some of the bugs in the 2 engines are inherited from Fruit actually. Fruit has very few bugs compared to other engines but some of the hack fixed bugs pop up when trying to cover your roots. I don't know how much if any GPL code either engine has, I am very open to the possibility that neither engine ever technically had any Fruits code in it at all. It is possible to rewrite Fruits algorithms in your own code and inherit the same bugs. Given the language barrier I don't think it is far to judge Osipov at this point. Keep in mind that people have very little to gain from making illegal clones of GPL engines and a lot to lose. The GPL gives programmers a lot of freedom to contribute to a project in a positive way. As someone who has not read this forum in several months it is disappointing to come back to see such a witch hunt for clones and so little positive computer chess talk.

I have mixed feelings about it.
It is clear that he has his own innovation in Strelka.
It is also clear that he has borrowed ideas from others.

There is one thing that is disturbing:
He consistently failed to give credit (at least for ideas) to:
Fruit
Rybka
Beowulf

His usage of information from each system is on the edge of right/wrong and I have no idea if he has actually broken rules. But (at least emotionally) I think it is wrong that he did not give any credit in his write up for Strelka. Now, there are others that have done similar things (borrowing ideas without giving credit is quite common in computer chess) but in this case it seems more extreme than others to me.

I actually feel dissapointment on both sides of the fence. It really cools my love for computer chess in general.

[slobo]

Strelka is not written in the style of fruit.

Fruit consists of three times as many C++ files as the C files of Strelka.
Now that I know the heritage, I can spot (for instance) that pawn_info_t of strelka and fruit are very similar. There are twice as many structure types in Fruit as there are in Strelka. There are 55 functions in Strelka and 257 functions in Fruit 22. Strelka is a bitboard engine and fruit is not. The style of Strelka's author is not like Fabian (does not use the assert() masterfully like Fabian for instance -- not a single assert in the whole code base).

The code is quite significantly rewritten, but I can now see the Fruit skeleton for some functions.

If "Strelka´s code" is very different from the Fruit´s one, does it mean, then, you are talking of Rybka´s code under the name of "Strelka" ?

[Daniel Mehrmann]

http://kasparovchess.crestbook.com/view ... 578#p93578

Hi and thanks for the information.

This is a clear violation against the GPL.
As a member of the FSF, i will send a message to the FSF to verfiy possible measures in this case.

Best,
Daniel

Well, the similarity to Fruit can not be very high anymore, else Dann Corbit etc. would have recognised it.
I'm more concernd about the evaluation and tables he used from Fruit or Rybka, which took hundereds of hours of testing to optimize in the first place.

It doesn't count. You can change each byte in the source, it will be always GPL. So, we have a rewritten Fruit with stolen Rybka parts. That what i call a funny clone.



I think this shows a new level of cloning and a perfect work anyway. I fear many more will follow if we don't stop it right here and strike back with the full power of the law.

Best,
Daniel

And what do you suggest,hunt him down in Russia ,wish you a bunch of luck in your mission....

Thats's not my task of course. This will be done through the FSF http://www.FSF.org . Somebody else informed the FSF already. Now we have to wait what the FSF says and maybe does in this case.

Best,
Daniel

[Dariusz Orzechowski]

Thats's not my task of course. This will be done through the FSF http://www.FSF.org . Somebody else informed the FSF already. Now we have to wait what the FSF says and maybe does in this case.

Informed about what? And on what basis?

[tiger]

Maybe the same applies to Rybka.

I'm not sure why you answer with a laughing smiley, it looks like a serious possibility to me given the latest information.


// Christophe

[George Tsavdaris]

Maybe the same applies to Rybka.

I'm not sure why you answer with a laughing smiley, it looks like a serious possibility to me given the latest information.

What latest information?