geots wrote:And again, i say 4 programmers who have studied it will never reach a unified decision.
Amazing! How about 5?! I believe I understand these gentlemen correctly and there is a general consensus.
Dr. Bob Hyatt, Matthias Gemuh, Fabien Letouzey, Dr. Alexander Schmidt, Zach Wegner... I would be willing to bet there are others who "know what they are talking about" would say at least a "more likely than not" burden of proof... if not much stronger.
I would be surprised one could not find 4 more!
geots wrote:We are getting dangerously close to what i call "Follow the crowd simpletons".
I would not say the "naysayers" are simpletons... just dyed-in-the-wool supporters of Vas or simply willing to naysay to justify what engine they wish to use.
geots wrote:I've talked to too many programmers-off the record and dont want to get involved in what they call this- a snake pit.
Notable Quotes I pulled... and this just from the, "Fabien's open letter to the community" thread.
"- Vasik claimed that Strelka 2.0 is a clone of Rybka 1.0 (and you know what that would imply!)" > Fabien Letouzey " - Zach Wegner found many Fruit ideas (and nearly identical code) in Rybka 1.0; I think someone else did, too" > Fabien Letouzey
"Implemented algorithms were "translated" to a bitboard infrastructure. The translator ends up with a working implementation of an algorithm he may never have been able to code from scratch. It is "copy and paste" with unavoidable adaptations/translations. That is how DanChess once cloned Crafty's evaluation, and was condemned in this forum as a clone." Matthias Gemuh
"More important is "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 says a lot about the issue. In a short summary, strelka encapsulates the ideas and data structures in Fruit, although there is not a character by character match since strelka came from reverse-engineering of Rybka 1. He makes it pretty clear that the "source" for strelka was obviously fruit. Which is what several of us have been saying for a long time. Function names and variable names are, of course, meaningless, assuming the original Rybka beta was stripped of all symbols for reasons unknown. But as I mentioned when the debate started, there are global similarities that are way too significant to write off as random chance of two different programmers writing the same code..." Bob Hyatt
"Of course, this is nothing new to those of us that looked and listened in the first place..." Bob Hyatt "Bob, We never really met, so, nice to meet you! I am sorry that many people apparently did not listen to you." Fabien Letouzey. " Me too. But if someone believes something strong enough, _nothing_ will alter their opinion. Basic human nature. We have now reached a totally insane point in computer chess where we have dozens of strong programs, claiming to not be derivative works." Bob Hyatt
"Proof that Rybka is a Fruit derivative has been presented since Rybka 1.0 beta, though some people will never accept any amount of proof as adequate." Matthias Gemuh
"VR used Fruit code. Noone who looked at the facts can disagree." " Takeing the code, and changeing it is a GPL violation. Thats what happened. There is no other explenation for similaries in non-chess-playing-related-parts like the UCI communication, error messages, crashes." Alexander Schmidt
Bob Hyatt: "Just for the record, to eliminate this specific argument, when Zach, CT, I and others looked at the fruit/rybka1 question, we did _not_ involve Strelka. Strelka was the thing that exposed the issue, but we directly compared fruit to rybka, so the strelka issue could not be raised again..."
Fabien Letouzey: " What happened then?"
Bob Hyatt: "We found _lots_ of similarities. Zach created a web page that went into great detail with the analysis. There are some obvious differences between Fruit and Rybka, but there are a _ton_ of similarities. Too many to be pure luck."
"I would like to put events into proper time-frame / perspective.
1. Strelka came along.
2. Vas looked at it, claimed it was Rybka and therefore he was going to release the strelka source under his name.
3. He then discovered that even if you take a source from a questionable place, once you modify it, the modifications are _your_ copyright. Since Strelka admittedly had some changes made (improvements according to Vas) he then realized he could not release it as his code as then he would be violating the "author's" copyright. Even though Vas had violated the Fruit GPL.
So he was damned if he did (release the code as his own) or damned if he didn't (someone else was getting credit and his ideas were exposed)...
That's all there was to that little episode." Bob Hyatt
"I am not sure how Rybka would be legal in light of the GPL fruit was issued under. I've not seen any source code for Rybka 1 beta, yet I have seen executables, which is a direct violation of the GPL. Strelka is a reverse engineered derivative of fruit. I am not sure what in the hell that means, however.
" Bob Hyatt
"Maybe we can ask other people whether they would consider it a new engine. Apart from the different ordering of moves with equal score (due to mailbox vs. bitboard move generation order), the engine behaviour would be identical.
Same search, same eval.
By "huge undertaking", maybe you mean that one has to understand CC basics and modify a lot of code.
But the way I see it is different:
Which is the hugher undertaking:
a) convert Fruit to bitboards
b) write a world-class engine (as of 2005) from scratch"
"I have always said that changing the infrastucture of move generation (e.g. from mailbox to bitboards) and then adapting (or "translating") the remaining source code is just another form of "copy and paste". The result of the adaption is not a new engine. As a chess programmer, I know what I'm talking about." Matthias Gemuh
"If you start with the complete Fruit code and change it, is it copy and paste? Yes. It's a copy of the whole code. You answered the question yourself. Thats what happend with Rybka, there is no other logical explenation for the similaries in not chess related parts." Alexander Schmidt
Rob O. / Watchman