Fabien's open letter to the community

[Prima]

if strelka is fruit (says fabian), and strelka is rybka (says vas rajlich), isn't this saying that rybka is fruit ?

Exactly! Straight from the horse's mouth (Vasik Rajlich) in the case of Rybka vs. Strelka. This could lead to potential legal problems or ethical issues for Vas, where the GPL license is concern. Fruit was/is open source with GPL license and Rybka is derived from Fruit, based on studies between Fruit & Rybka, but closed source and commercial.

Tord, thanks for this post. It explains a lot and confirms what the experts who studied Fruit-Rybka-Strelka have been saying all along.

[kingliveson]

And there was: viewtopic.php?f=3&t=297

[BB+]

I think the most relevant part of Osipov's comments as to Fruit/Rybka are:

6.And the most legally suspicious thing : I carefully studied the code of Rybka using disassembler trying to understand the algorithm of its work. Altogether, I studied about 20% of the code. I am not interested in how works UCI-protokol or other functions, such as move generator. I already have my own ones, and I was not intending to engage with any protocol, since I was not going to make an engine.
I was only interested in search heuristics and evaluation function. This allowed me to achieve greater similarity (resemblance) with Rybka. In addition, I found that Vasik walked the same way (path) – he has taken Fruit as a basis, rewrote it to bitboard and included tables of material imbalance of Kaufman. Some of the tables I kidnapped (ravished) from the Rybka.

[BB+]

Incidentally, there are pictures of Markov and Osipov(?), see the May 9th entry for 2007 at http://www.sdchess.ru/march_oct_07.htm

There is also an interview: http://www.sdchess.ru/osipov_int1.htm
This is a curious exchange:

5. Еще один вопрос связан с Вашим публичным появлением под псевдонимом. Это нежелание стать публичным в мире шахматного программирования и Ваша внутренняя склонность к “криптографии”?

Этот вопрос я хотел бы оставить без комментариев. Псевдоним имеет реального прототипа, и я бы не хотел ничего об этом говорить.

[Howard E]

Incidentally, there are pictures of Markov and Osipov(?), see the May 9th entry for 2007 at http://www.sdchess.ru/march_oct_07.htm

There is also an interview: http://www.sdchess.ru/osipov_int1.htm
This is a curious exchange:

5. Еще один вопрос связан с Вашим публичным появлением под псевдонимом. Это нежелание стать публичным в мире шахматного программирования и Ваша внутренняя склонность к “криптографии”?

Этот вопрос я хотел бы оставить без комментариев. Псевдоним имеет реального прототипа, и я бы не хотел ничего об этом говорить.

Is there an English translation available? Thanks.

[thorstenczub]

the next ethical question for the elo-list-groups could be:

is it right to have rybka in our rating-lists ? shouldn't we throw Rybka out
of the rating list ?

that would be logical and understandable.

the same question could be used for ICGA-championships and other tournaments:
as long as vas rajlich did not hand out the source codes to a team with fabien letouzey
in it, and fabien gives his ok, should rybka be allowed to participate in championships
or tournaments ? i don't think so.

i would advice a board of bob hyatt and fabien letouzey and another reputated programmer to analyse the source codes of rybka 2 and rybka3 to find out how much similarity is in it.
if this is done, and nobody finds similarities or copied passages,
rybka is allowed to continue as participant. otherwise... it would have
to be banned from computerchess tournaments and championships arround.

[BB+]

Is there an English translation available? Thanks.

Well, I'm not completely happy with the automatic ones, but:

5. Another issue associated with your public appearance under a pseudonym. This reluctance to become public in the world of chess programming, and your inner propensity to "cryptography"?

This issue I would like to leave without comment. Alias has a real prototype, and I would not want anything to talk about it.

So it has something to do with "Yuri Osipov" being a pseudonym.

[kingliveson]

Is there an English translation available? Thanks.

Well, I'm not completely happy with the automatic ones, but:

5. Another issue associated with your public appearance under a pseudonym. This reluctance to become public in the world of chess programming, and your inner propensity to "cryptography"?

This issue I would like to leave without comment. Alias has a real prototype, and I would not want anything to talk about it.

So it has something to do with "Yuri Osipov" being a pseudonym.

10) The same person Yuri Osipov Ivanovici (is he real ?) is stating in one of the above fora that you the Convekta company wanted to publish his engine but you got Vas veto. Is this a true statement ? He also is stating Rybka might contain substantial code parts from the Fruit chess engine, what is your opinion about this ? Is it possible to do something against these in our opinion defamatory statements ?

I consider that Yuri Osipov (Ivanovich) is his real name. He didn't hide it. However I can't state this with 100% assurance. For a long time Convekta developed Rybka GUI for mobile platforms (PocketPC and Nokia Smartphones). As Rybka engine was not ready yet and Convekta needed to have some income from this development we agreed with Vasik Rajlich to sell GUI with another engine for a while. I sent proposals to a few engine authors for making their engines mobile and to release with Convekta GUI. One of them was Yuri Osipov. He agreed to publish his engine. Knowing about possible legal problems with Strelka we asked Vasik for his opinion about this. The message was sent by Osipov first and then I duplicated Osipov's message as Vasik didn't receive it. The answer was no. So this quesion was not considered any more.

2010-01-24
Ippolit/Robbolito/Igorrit/IvanHoe/Firebird

191, MD http://www.playwitharena.com/?Newsticker:Archive_11

[Ted Summers]

It's going to be a difficult case, Vas never saved his sources codes, he doesn't have the Rybka 3 one, so I'm sure he doesn't have the code of Rybka 1.1 or 2.0, all the investigations would need to be done as reverse engineered code.

It was unfortunate that Vas claimed Strelka's code as his own, since later it was found out that it had significant parts of Fruit.

As about the ply and node count obfuscations, they have been explained at Rybka forum, 3 plies are added to normalize the count relative to other engines, as earlier plies are "thinner" and don't fulfill their definition of ply, nodes are recalculated so they can be used to compare different hardware, i.e. higher nodes must mean higher strength at all times, unlike other engines that with hyperthreading show higher node count but play weaker.

Question: If Vas LOST Rybka 3 Sources, Then how the Hell did he write Rybka 4 so fast. That is a hell of allot of code for a very strong program.

[jjh13]

Question: If Vas LOST Rybka 3 Sources, Then how the Hell did he write Rybka 4 so fast. That is a hell of allot of code for a very strong program.

I think Vas meant that he lost the Rybka 3 sources AFTER he developed Rybka 4 from them. He failed in archiving an older version.