Fabien's open letter to the community

[Terry McCracken]

My good friend Fabien Letouzey, author of Fruit, asked me to post the following message for him:

Hello,

Long time no see.

First, I am not back to computer chess, sorry about that. I just want to clarify a few things. Sorry if that's old but there is some misunderstanding I need to fix, and I found out only yesterday. Bear in mind that I am mostly unaware of what has happened for five years though.

First there was the Strelka case. Dann approached me with some "Strelka" source code for me to check. I had never heard of it. I assumed it was some closed-source free engine and that people wanted to know whether it was based on the Fruit source code.

The short answer was "no", it was not a verbatim copy of the source code. All the code had been typed (can't say "designed" though, see below) by an individual. So legally there was no issue that I knew of. It was however a whole re-write (copy with different words if you like, similar to a translation) of the algorithms. Not just an extraction of a couple of ideas as is common, and normal.

That being said, some original changes and ideas were also included in the program. So it was, as has since been stated many times in fora I suppose, a bitboard re-write of Fruit with some personal (or otherwise) ideas. Also note that the source code Dann sent me might not be the from the 2.0 version.

Edit: I've just had a look at the 2.0 sources. On top of what I said above, there are many constant and function names that are identical to Fruit's. I remember noticing it back then as well.

Hope it helps, because my email answer to Dann was unusually short and cryptic even by my standards. And Dann, please next time make it clear when you want a public statement instead of a private opinion, thanks.

I want to point out something immediately: there was no mention of Rybka whatsoever. Indeed I was unaware of any relation between Strelka and Rybka, this is precisely what I learned only yesterday. I insist because it seems I have often been quoted about "not caring" about the (possible) Fruit/Rybka relationship, but this is not so. Strelka did not look like a problem because I assumed it was free.

Next, I was approached by Ryan (I think) and Christophe Theron about whether I could help with some "possible Fruit code inside Rybka" issues. I answered "yes, but how?", but did not get a reply. This did not make me really aware of a clone possibility however because I thought they were talking about some insignificant UCI-handling code or whatnot. Also this was several years after the initial Rybka release, and I guess quite a few people had a close look at it. Apparently Chrilly did?

Now if someone could tell me a bit more about the major events last five years and the current state of affairs, I'd be much obliged.

A few things I noticed yesterday, can you confirm?
- Rybka search info was obfuscated in some way (like displaying depth-3 or something), any pointers on details please?
- Vasik claimed that Strelka 2.0 is a clone of Rybka 1.0 (and you know what that would imply!)
- Zach Wegner found many Fruit ideas (and nearly identical code) in Rybka 1.0; I think someone else did, too
- Some even stronger open-source program appeared as a decompilation of Rybka (with own ideas, sounds familiar), what came up of looking at those?

Any questions, now is the one time to ask.

Thanks for your attention,

Fabien Letouzey.

By Silvian, a creative member at the Rybka Forum.

Rybka-Fruit GmbH

[BB+]

In all, I don't really care what most of these characters say, but it's a bit disappointing to read intellectual dishonesty coming from those whom you respect for their work in the chess community.

I guess I've just seen this so many times in my life by now, that it can't shock me much. And I said in my dismay, "No man can be trusted..." (Ps 116:11).

I still think the best was "Of course he lies. That just shows he is no idiot." [Along with the sudden shift to the legal aspect: "Well, being a liar is not illegal, when you are not given evidence in court."]

It is a bit amazing how the show has suddenly shifted to the "legality" foot for many, when at the same time R3/IPPOLIT was phrased as an "ethical" issue if the "stolen code" flag-rallying could not be made to stick. Perhaps the best I can say is that the CCRL moderation seems not to have been stressed into over-drive yet.

[orgfert]

Perhaps the best I can say is that the CCRL moderation seems not to have been stressed into over-drive yet.

Perhaps if they could bring themselves to think on their opponents time and learn from past moves of dubious merit ...

[thorstenczub]

"mythology" ?

You deny that there are commercial interests in hiarcs, rybka, talkchess forums ?

[orgfert]

"mythology" ?

You deny that there are commercial interests in ... talkchess forums ?

At talkchess there is none.

[Howard E]

Hi Fabien,

1. In your letter does "yesterday" mean this present time in Jan, 2011 or is this an older letter?

2."I want to point out something immediately: there was no mention of Rybka whatsoever. Indeed I was unaware of any relation between Strelka and Rybka, this is precisely what I learned only yesterday. I insist because it seems I have often been quoted about "not caring" about the (possible) Fruit/Rybka relationship, but this is not so. Strelka did not look like a problem because I assumed it was free." F.L.

This paragraph is telling. For me it means that you have a major concern that a programmer may have used large portions of Fruit (a free one) to make a commercial one. Is this a true interpretation of your words?

3."Vasik claimed that Strelka 2.0 is a clone of Rybka 1.0 (and you know what that would imply!)" F.L.
From what I've read this has been confirmed, that Vasik did claim that Stelka was his work.

Is it confirmed for you now also?

Are the implications that Rybka 1.0 is largely your work with a few additions?

Thanks Fabien for your chess program and all the best to you in your future endeavors.

Howard Exner

[alfons]

BB+ wrote:

It is a bit amazing how the show has suddenly shifted to the "legality" foot for many, when at the same time R3/IPPOLIT was phrased as an "ethical" issue if the "stolen code" flag-rallying could not be made to stick. Perhaps the best I can say is that the CCRL moderation seems not to have been stressed into over-drive yet.

Yes, all true.
But I welcome hgm's sober thoughts on the issue:

* Rybka is a legal derivative of Fruit

from: http://talkchess.com/forum/viewtopic.ph ... 43&t=37762

I think it sums it up pretty nicely and decent: "derivative" [work from Fruit].

Mind you: Mr. Fischbrät never commited himself to this kind of refreshing honesty.

Maybe the statement*: "I went through the Fruit 2.1 source code forwards and backwards and took many things." has to be altered to "[...] and took things I understood, could elaborate, implement, which sounded feasible and were cheap enough [...to catapult my Fischbrät to number one chesslisttestingcrookwise]."

memovox regards


a.

*from ze interview: http://chessprogramming.wikispaces.com/ ... #Interview

[Sentinel]

At talkchess there is none.

You all (Bob included) just wave how Sam blows. He gives you a little illusion of control and power, but in the end it's his own interest that is supported. Whether his interest is classic commercial interest as CB is another question.

[Harvey Williamson]

Q: Why don't you allow participation of Ippolit, Robbolito, Houdini engines on your online chess platform?
Harvey Williamson: Those engines are suspicious. Vasik Rajlich said they are clones of Rybka, and they're not listed by CCRL.

One thing that is illegal all over the world is to quote words that have not been said.

[Jeremy Bernstein]

Q: Why don't you allow participation of Ippolit, Robbolito, Houdini engines on your online chess platform?
Harvey Williamson: Those engines are suspicious. Vasik Rajlich said they are clones of Rybka, and they're not listed by CCRL.

One thing that is illegal all over the world is to quote words that have not been said.

An additional universal all over the world is satire. But Harvey Williamson, as long as you're here, I have a question: Why don't you allow participation of Ippolit, Robbolito, Houdini engines on your online chess platform?