Reports | July 17, 2011 0:15

Rybka affair: Rajlich speaks

Rybka disqualified and banned from World Computer Chess ChampionshipsIt seemed that Vasik Rajlich, the programmer of Rybka, had been silent ever since he had been disqualified and banned by the International Computer Games Association (ICGA), at the end of June. However, as it turns out he gave a half an hour interview on July 4th already, which has been posted on YouTube. "'I had a nice little spike of sales," said a down-to-earth Rajlich.

On June 29th we broke the news about Rybka: the chess program and its programmer Vasik Rajlich had been disqualified and banned from previous and future World Computer Chess Championships. The ICGA accused Rajlich of plagiarizing two other programs, Crafty and Fruit, and demanded that he returns the trophies and prize money of the World Computer Chess Championships in 2007, 2008, 2009 and 2010.

The news made the mainstream media: it was picked up from ChessVibes by the influential ExtremeTech and then copied by hundreds if not thousands of sites, including the New York Times and Der Spiegel. The chess news site of Chessbase, who distribute Rybka, didn't cover the story at all. In their shop, Rybka 4 still has the JPEG image with the tag line 'Computer Chess World Champion'.

Shortly before putting the story online, we had sent an email to Vasik Rajlich asking him to comment on the allegations. Unfortunately we never received an answer from him, and it seemed that the programmer remained silent to other media as well. However, during the last week several readers pointed out to us that Rajlich did agree to an interview, which was posted on YouTube. It was conducted by a Nelson Hernandez, who seems to be good friends with him.

Rajlich starts with a personal statement:

Before we start I'd like to make a short statement about these ICGA allegations. First, I did not wrongly omit anything from our entry form, nor did I break any other tournament rules. I did not list Fruit on the entry form because there is no direct game playing Fruit code in Rybka. Rybka uses a different board representation than Fruit and uses a different structure of search routines, so this should be quite clear. Now it's true that I did take a number of things from Fruit which are above the level of source code. This is something that I discussed many times, something which is perfectly normal practice, and it's not something which is asked about on the entry form.

Vasik Rajlich at the Computer Chess World Championship in Turin, 2006

Second, Rybka 1 was already disassembled and published back in 2006. Everything about Rybka 1 has been completely transparent for 4 1/2 years or so. So if somebody, if one of our competitors or the ICGA had a problem with something in Rybka 1 or with information that I provided on our entry form, then that was the time to raise it, you know, before the tournament. Once our tournament entry is approved, there's no grounds at all for reversing course and applying some kind of retroactive penalties. Third, if the ICGA wants to open this Pandora's Box of what exactly is an acceptable level of similarity, why is Rybka being singled out? Why is Rybka being the only engine which is investigated?

(...)

If the ICGA wants to go down this path to establish some kind of quantitative measures of what is and is not acceptable, they need to apply those measures to every single participant. Fourth, I completely disagree with this entire business that was conducted. There was all kinds of public statements and accusations, the ICGA made an accusation. By the time I was asked to address the accusers and discuss the topic with them, which was again not at all a proper protocol, by this point they had themselves made multiple public statements. So it was pretty obvious to me that this was not going to be some sort of a fair hearing and so I did not participate.

Vasik Rajlich at the Computer Chess World Championship in Turin, 2006

Then Hernandez asks Rajlich whether there is any code from Fruit in any of the Rybka versions. Rajlich:

Rybka has numerous code from other programs from the public domain inside. I use that throughout the code, that's accepted practice and that's legal and that's code that's in the public domain.

Certain public domain functions may well be in Fruit and Crafty as well, so they may be shared with me and Crafty, Fruit and Rybka, I'm not really sure. And it's even entirely possible that I would have taken them from Crafty and Fruit and put them into Rybka. For example the Nalimov tablebase code, that I remember quite specifically taking from Crafty. And that's normal.

In the interview Rajlich didn't want to comment on the ICGA's findings and in general he seems to have reservations in accepting the ICGA as a legitimate governing body. Rajlich also denied that he violated the rule involving program originality. We wouldn't be surprised if the Rybka programmer was preparing a lawsuit against the ICGA. To the question what he's going to do now, the answer was: "no comment". Asked about the effect of the negative publicity, Rajlich said: "I had a nice little spike of sales."

Peter Doggers's picture
Author: Peter Doggers

Founder and editor-in-chief of ChessVibes.com, Peter is responsible for most of the chess news and tournament reports. Often visiting top events, he also provides photos and videos for the site. He's a 1.e4 player himself, likes Thai food and the Stones.

Chess.com

Comments

Merlinovich's picture

@Dennis M
Anybody who claims Rajlich looks very innocent must be delirious (by the way I'm not being ironic here). I am sure he would have been burned on the stakes as a witch in 1450.

"So as I understand it, Rajlich is only off the hook here, maybe, if what he took was only public domain and what he took was more or less irrelevant to how the program finds, calculates and evaluates moves." No reason 1: when getting close to endgames, call(s) to tablebases will most certainly change search, calculation and evaluation results even though these positions have not arisen yet on the board. No reason 2: there are public domain algorithms that effect all 3. No reason 3: Even copying copyrighted protected material that doesn't directly affect the 3 will if proved be an infringement that is punishable.

Your Hamlet example is very good. ICGA has succesfully rejected participants before that copied a chess program literally. However, Hamlet was in fact written based on ideas from Amleth, preserved by Saxo Grammaticus, and is therefore not an "original work". What Rajlich did was to analyze Hamlet and say "what mechanics make Hamlet work so well, hmm, an uncle killing the father of our hero, his mother, his desire and hesitation to kill his uncle in revenge etc. etc. Now comes Saxo and Shakespeare and accuses Rajlich "see you did exactly the same as me, you cheater!". Who should we believe?

Copyright is all about preserving ideas and originality, but not in a general way, only in a literal way. The purpose is to encourage making and even investing in ideas without automatically making it impossible for others to use those ideas in a different implementation. That is exactly why ICGA shy away from using it, because they know the most valuable thing in chess programs are exactly the ideas and not implementation, so they define this "originality" claim that is supposed to mean that each programmer go away to an isolated place and figure out ideas, and not let themselves be influenced by anybody else's ideas. It's an impossible goal which clearly would have failed in a business world because by presenting an idea you will have patented it forever, and even a programmer that painstakingly invented the same idea in his isolated workroom and now come out to present it, will not be able to because somebody had and presented the idea first.

When I look at the comparison of the evaluation algorithm of Fruit/Crafty/Rybka and other programs, the whole presentation is (to me) just ideas. Once the mobility is born as an idea, there are just so many ways you can calculate knight mobility, bishop mobility, rook mobility etc. It is just beyond me why Crafty calculates bishop mobility and rook mobility, but not knight mobility and queen mobility, while Fruit/Rybka calculates all 4, but that is now used as an argument to say that Rybka is a copy of Fruit, even though there are minor differences in implementation between Fruit/Rybka in many of these algorithms.

The dilemma here is the imperfection of the copyright paradigm, and all the programmers in ICGA can't stand that it can be so easy to copy their ideas. I sympathise with that, but not with how they are bashing Rajlich with it. The reason we have the currently strongest program Houdini is because a collection of ideas were copied and then tuned in a better way than those from which it was taken. That is why Houdini won't participate in WCCCs, but it makes these tournaments kind of hollow, made for hobbyists with a pure morale of only using their own ideas. In reality it is easy to prove that these high standards are in fact hollow themselves. Why are there fora with chess programmers discussing algorithms lively, even implementations etc.? The are not taking the ICGA oath seriously to "only use original work".

And that is in the end beneficial for us end-users. We get stronger programs when they all copycat each other. But ICGA president David Levy thinks it is disgusting. Don Quijote would have been proud. Go bash some windmills. (irony may have been used here).

Mentor's picture

Rybka will be forgotten in 3 or 4 years time.

Chessbase will now actively look for new engines / new talent.

Rajlich may attempt to re-brand but he is finished in this field.

Daan's picture

nanos gigantium humeris insidentes

and

'In computing, we mostly stand on each other's feet.'
-- Richard Wesley Hamming

sundararajan ganesan's picture

it is disappointing that vishy anand is not playing for India,( he never plays for the country in the olympiads) yet again! this is a major chink in the otherwise pleasant/positive persona of anand.

Michel83's picture

@ Merlin

Thanks for your answer, I will look into the links. From a legal point of view that's all quite interesting.

On a little side note: If you have the scrips for this site (chessvibes) switched on, you should be able to answer to somebody directly by clicking on the little "answer" button at the end of their post. Like this I had to scroll down to see by chance you answered to me further down.
No offense, would just make it easier. : )

ll's picture

Bad faith, downright arrogance, and not that clever after all. Was VR glad to accept the World Championship titles from ICGA to spike his sales? Not he'll gladly ignore them. Btw did he also cheat to get his IM title (using a computer in the bathroom..) . Who knows now? There is nothing worse than shameless denial. Next stop a chess game with Gaddafi?

Dennis M's picture

I recognize that there's a difference between open source and public domain and that Rajlich may be confusing the two. However, even if the code he took really was in the public domain, how is that a sufficient defense if he's accused of violating an ICGA rule about the software's being his own original work? Shakespeare's works have long been in the public domain, but I'm not going to win an award for best new writer by republishing "Hamlet" as my original work.

So as I understand it, Rajlich is only off the hook here, maybe, if what he took was only public domain and what he took was more or less irrelevant to how the program finds, calculates and evaluates moves.

MICHAEL's picture

Yes i think what he is saying is that its standard practice among programmers to use codes in the public domain, what he is saying is that his codes have been used also by others and he use s others and that between programmers this is normal standard practice, so one will have to investigate every programmer and every engine to see who used what from whom and either punish them all, or no one.
Who ever made these complaintS must be totally innocent of not using anyones codes and thus a programming saint
THIS IS WHY HE ASKS WHY IS RYBKA BEING SINGLED OUT WHEN ALL ARE GUILTY OF USING stealing from each other.
Maybe its an unspoken rule among programmers but the original code writers might be in for a windfall if there codes are being used by everyone but again he states they were already in the public domain

The Terminator's picture

I think Rajlich took all the best parts of all open source engines he could find but then he gradually implemented his own ideas after years of painstaking research which resulted in Rybka being the strongest engine in the world for several years.

Taking source code from Fruit and Crafty, etc., probably saved Rajlich years of painstaking coding, or else he would have done all programming himself if it only would have taken him a few months or so. He took the short path. This is the main reason for the authors of those programs to be upset with him.

The other reason is that he have (or never had, according to the ICGA rules) the Computer World Chess Champion title and earned money from it by selling Rybka. This must feel awfull to the authors of the engines that Rajlich took source code from, that they put years of hard work into their engines, and some of this work went into Rybka and they got nothing out of it!

By using the source codes of those engines (Fruit and Crafty, etc.), Rajlich could, in a relatively short period of time, concentrate on his research and improvement on the hardest parts of the chess-playing algorithm of Rybka, namely the evaluation of positions, move ordering, and tree search algorithm.

Those are by far the most important source code parts of the engine that decides the playing strength of the engine and that is Rajlich and the Rybka teams original work. This is what made Rybka play 100-150 ELO stronger than all the other engines, not the source code that Rajlich have used from the other engines and put into Rybka.

This is what Rajlich mean when he says that he have not taken "original" source code from other engines, and that is why he does not feel that he have done anything wrong when he participated in the Computer World Chess Championship.

I think it is most important that nobody who enters the Computer World Chess Championship competition have stolen any original work from other engine authors.

More or less all engines use the well known algorithms that have been with us for decades: AlphaBeta, iterative deepening, SEE, table bases, and so on. Those are ideas that came from the greatest contributors in the area of chess computer research.

Rajlich, like many others of today's top engine authors have not contributed to the public domain with such kind of algorithms like the legendary AlphaBeta algorithm, iterative deepening, or table bases, just to name a few. Such original ideas seems to be much more rarely discovered nowadays, and new original ideas have much less impact on the playing performance.

I think something much more radical is needed than small refinements of old ideas and algorithms if chess engines are to raise in playing strength by orders of magnitude and I strongly believe that this is possible only with new and different algorithms.

Etingle's picture

Imagine #1 in the world (Anand) cheating and NOT mentioning it. That's why journalism and commerce doesn't go together.

Jeremy Bernstein's picture

That is normal, but that's not what he did. He took Fruit's evaluation, arguably the hardest part of the engine to write, and converted it verbatim to bitboards. Then he added some other things. That's not "taking ideas", any more than a greek translation of War and Peace is -- the final product, while the result of probably years-long hard work on the part of the translator, isn't his. It's remains a book by Tolstoy.

Thomas's picture

I am neither informed nor interested in the main discussion, but I am a bit puzzled about Chessbase-bashing: They are the only site which is rather regularly criticized (elsewhere) for not covering certain events or news - as if they were (legally? morally?) obliged to "mention everything". As R.Mutt wrote above, they had been "ignoring" Rybka for quite a while, instead promoting their own Fritz products. Back then they were also criticized, would they now get praise if they had stuck with that policy or business decision?

"Chessbase might just be as liable ..." - I am not a legal expert, but is a publisher or selling agency responsible for "mistakes" or copyright violations by authors? If a book contains plagiarism, should the publisher thoroughly check all 400 pages and _necessarily_ find out?

Can buyers demand a refund? This might only be the case if it now becomes illegal to use Rybka for whichever private purpose - casual games, game analyses or opening preparation. Else, I think only Rybka's competitors can sue Rajlich (and maybe Chessbase).

bhabatosh's picture

I felt the same . There are some valid points like before the findings went public they should have discussed this internally. probably ICGA must have tried , but if not he is probably right in that.
otherwise the whole interview is like everyone copies stuff and so did i, what's wrong ? he is taking code from public domain for free and then selling them as his own , is that right ??
i guess not .

skybon's picture

In fact, it *is* right. Public domain means surrendering all claims on the future of code.

Jeremy Bernstein's picture

In that case, they would have to admit other derivative engines, such as Houdini. Which they shouldn't, and don't. Strength isn't everything -- if Kasparov, Anand or Carlsen were determined to have reached due to cheating, their World Champion or #1 rating list status wouldn't be valid, either. What you find useful or use on your computer at home is one thing; what is officially accepted, endorsed and titled by a "computer games association", essentially an organization of and for programmers, is quite another. Professional ethics matter.

R.Mutt's picture

Before they started selling Rybka in 2008, Chessbase didn't mention its successes a lot.

So it's only logical that now that Rybka's reputation is going down, Chessbase ignores that too.

That's journalism for you.

Eiae's picture

Chess960 is the solution. Then we can leave behind all this stupid computer talk

blueofnoon's picture

Not sure what you are talking about.

Top engines beat human GMs without much problem in chess 960.

christos (greece)'s picture

Yes, but this is a little hard to believe.
It means that while he was scanning the source code of Crafty and Fruit looking to decide which parts to copy, he was carefully taking notes about each code fragment's licence, so as not to do anything illegal (by the way, I thought there is only one licence which covers their whole source code). And so, for the Nalimov Tablebases part he copied verbatim, while for other more "protected" parts he only "took some ideas" and he massaged/rewrote the source code. which is perfectly normal.

bernd's picture

One can only guess at how Chessbase would have reacted if they did NOT sell Rybka, but I'm pretty sure they would not have kept quiet.

Septimus's picture

To be fair to the guy,this excerpt of his interview sounds very reasonable.

For most readers like me who do not remember the specifics (technical and procedural) of how this went down/evovlved, it gets confusing.

If there are no specifically written rules then these allegations/findings do not stand on legal ground.

Perhaps Peter can write some kind of a baseline article that really sets the proper context/framework for this dispute? As it now stands, to me, this seems like a mud slinging contest.

I really think CV should take this a step further than merely publishing interviews from both sides.

Have a nice weekend guys!

Septimus's picture

To be fair to the guy,this excerpt of his interview sounds very reasonable.

For most readers like me who do not remember the specifics (technical and procedural) of how this went down/evovlved, it gets confusing.

If there are no specifically written rules then these allegations/findings do not stand on legal ground.

Perhaps Peter can write some kind of a baseline article that really sets the proper context/framework for this dispute? As it now stands, to me, this seems like a mud slinging contest.

I really think CV should take this a step further than merely publishing interviews from both sides.

Have a nice weekend guys!

Merlinovich's picture

@Igor
Too many comments on guilt and possible consequences on this thread, and too little on how make a proper comparison of any two chess programs.

I think AFC could work in a court of law, since with a real copyright infringement case, Rajlich would stand with a lot to lose with a commercial program, and would probably have to hand in Rybka source code. In this case I am sure that whoever would revise the code would not be his competitors from recent CC tournaments, but impartial software people which also would have fresh eyes to recognize whether copyrignt infringement had taken place or not. The first step of AFC is for the authors (of Fruit & Crafty) to lay out what pieces of the code is supposed to have been infringed, and I have not seen that at all. In fact the only place I see considerations on what should be compared and fair/unfair use is in the introduction of the "Quantifying evaluation features" document.

A few abstracts:
"1.1.1 Levels of abstraction (analogy to copyright)
Although the ICGA investigation is not centered on copyright, there are many
philosophical considerations that inform both copyright law and the concept of
originality as pertinent to the ICGA. In this genre, Jeremy Bernstein provided a
PDF of a 1988 Boston College Law Review paper by J. Dianne Brinson entitled
Copyrighted Software:.. " and goes on to compare Romeo and Juliet with West side story. Is that the standard of comparison? If we are not evaluating copyright, but an analogy, what is it then and how should we compare?

"1.1.3 Whether evaluation features can and should be measured
Another question is whether evaluation features can actually be measured with
any validity. As Brinson notes (citation as above), in the context of copy-
right, unprotected ideas have been separated from protected expression for such
widespread areas as fiction and plays, non-fiction, songs, labels, jewelry, games and contests, works of visual art, television show characters, and videogames.
While the methods used here would not meet the most stringent notion of "sci-
entic", it seems there is adequate precedent for making more "quasi-scientic"
conclusions that are reliant on means that are not necessarily completely objec-
tive." Huh?? I must admit I fail to find any guidance whatsoever in this. What kind of "not necessarily completely objective comparisons" are we supposed to make?

Michael Lubin's picture

Vas' responses are totally disingenuous. HE DIDN'T KNOW Letouzey was the first to accuse him of plagiarism? Even his friend Hernandez was cracked up by that. The whole time, Vas is just projecting a vague party line that lets himself off the hook so that he doesn't have to go into the meat of any of the issues. He acts like he's paid almost no attention to the accusations the whole time. It's just not plausible. He's a likable guy, but he's also a slick liar.

Igor's picture

@Merlinovich
"Admitting that Crafty and Fruit and Rybka have common calls to e.g. Nalimov tablebases which in general might be considered public domain, is not admitting guilt. If he copied code for calls to this functionality, how could his program Rybka suddenly be “non-original work” when that apparently doesn’t apply to Crafty or Fruit? The point is that these calls were already in the public domain, so it didn’t matter if he copied it from Crafty or any other source."

Well you are right to a part here, but this speaks to how he copies code. Because you can only be sure that you are taking public domain code if you actually take it from the public domain. If you take it from a licenced programm YOU CAN NOT BE SURE that you are actually using 100% public domain code unless you go through it line by line. Thats why copying the tablebase code from crafty is wrong.

Over all after i went through the icga points (i am a computer scientist myself) and seeing his "defense", where i had hope to actually hear anything to debunk the icga publication. I have absolutly no doubt in that he is guilty.

Btw. wtf is that he didn't receive prize money (in the way he understands prize money). Wth is that all about? He can't be serious, can he?

arkan's picture

Why doesn't Chessbase respond to this?

Chessbase might just be as liable for having sold Rybka all this time from a legal point of view, i think they are frantically trying to deal their way out of this with multiple parties involved.

I can imagine that when i put my chess-engine up for sale via Chessbase, it will be heavily scrutinized (the sourcecode i mean) before it ever makes it into their shop. So if it turns out the engine was plagiarized, as ''ruled'' by the ICGA, they too have a problem. They sold thousands and thousands of copies (assumption!) of an engine which they SHOULD have known was a ripoff of existing ones.

The wait now is for buyers who bought Rybka via Chessbase to demand a full refund, or sue them in court

Arne Moll's picture

And it’s even entirely possible that I would have taken them from Crafty and Fruit and put them into Rybka. For example the Nalimov tablebase code, that I remember quite specifically taking from Crafty.

To me this is the weakest part of his defence, which otherwise doesn't sound unreasonable. But this I don't understand. He's had weeks to sort out his code, to think about its origins and look up any documentation, but instead he's still using vague terms like "entirely possible" and "I remember". How odd.

Remco Gerlich's picture

Same with other software, like Microsoft Office or whatever -- it's got a license and all, but who cares: it's public domain if I want it to be. Right?

brianinski's picture

"I just don't care, I mean my answer really is that I just don't care." says Vasic Rajlich.
WOW this is a classic example of a human being escaping reality by failing to take responsibility. There are only two directions to life, success as a person and failure as a person. Success features responsibility which spawns Integrity, Rajlich has chosen failure by blaming others and childishly escaping reality.
"It doesn't matter" How Pathetic!
Return the prize money. Perhaps 'to do the right thing' is beyond you.

skybon's picture

No, he decided not to really mess with bureaucrats like ICGA. Nerves do not heal.

"Return the prize money."
Is Rajlich legally obliged to do so?

Merlinovich's picture

@Arne
Perhaps it is not so odd that his comments on where it was copied from is vague since it was irrelevant to the charges. That is why the Nalimov code was not mentioned in the prosecutor's documents.

I sense Rajlich has a very different sense of what accusations he needs to answer than most people - perhaps that is why the witch hunt started in the first place 4½ years ago. He has heard the crying "the wolf is coming" from the chess programming community ever since that I can understand the fatigue.

From Rajlich's lack of interest in the case, it is clear he will not press charges against ICGA. The only hope to clear up this mess is if ICGA takes him to a "real" and impartial court which will first have to set up the protocol for how the originality claim is actually going to be measured (if it can at all). ICGA has used precious little effort on establishing a protocol. Apparently they think "originialtiy" is so easy to understand that it needs no context. However in programming, and especially chess programming, that is far from trivial. I wonder how you could ever disassemble (any) two chess programs and not find a lot of similarities - so protocol is everything.

Michel83's picture

Him and the Rybka-team never showed any fatigue in publically&agressively claiming other programs were clones of Rybka (without giving evidence). They've always been very good at "witch-hunting" themselves- at most you could claim that all the programmers have been battling each other since that time, but one can hardly say it was a "witch-hunt" against only one specific program.

But I agree that his sense of reality is quite a different one. And I do think that there needs to be a protocoll or something about programming and source codes, otherwise we'll have accusations and counter-accusations for the next 20 years. If a "set of rules" about "originality" is possible in programing I do not know, I'm not an expert.

Has there been similar cases at court about computer programs, programming and "copying" codes outside of chess programs, with other software or websites? Must have, no? An analogy would interest me.

Excalibur's picture

Houdini and Critter > Rybka.

Michel83's picture

Pssst...I think there was a hint of irony in what christos wrote...
;)

Bolo's picture

I suppose maybe nowadays to get top ELO ratings each chess engine is doomed to use very similar algorithms and programming techniques. Maybe there is a very little room for new original ideas here. Thus it is possible all chess engines developers use partially the same code, routines etc. so maybe all top rated engines are cloning each other and their predecessors again and again. We cannot know this for sure but only independent verification of all top engines' source codes can give a definite answer. However on the other hand I cannot imagine such procedure...

Just my five cents.

blueofnoon's picture

"Thus it is possible all chess engines developers use partially the same code, routines etc. "

This is probably true.

The problem is Rybka team has continuously accused of other engines for "pirating" their codes while they were using codes from other programs possibly more often than any other engines ever did.

blueofnoon's picture

The difference between "public domain" and "LGPL" or any other so-called "copy-left" licenses is quite clear.

No one in the information-communication industry would misunderstand it, not to mention programmers.

If Rajlich believes he only "borrowed" public domain part of Fruit or Crafty, the community is more than welcome to see the evidence, but so far he has declined to do so.

The impression I get is Rajlich is just talking, but in fact he knows what he did.

skybon's picture

Why should innocent-until-proven-guilty show any evidence?

Merlinovich's picture

@Michel83
Thanks for your response, I agree with all of your points. Concerning protocol something like this might do:
http://digital-law-online.info/lpdi1.0/treatise24.html
And remember, the devil is in the details, as they mention in the first paragraph.
See also
http://en.wikipedia.org/wiki/Abstraction-Filtration-Comparison_test
In either case since a program is not a novel or a painting, you can't compare them the same way. You have to establish a protocol to what can be compared and what can't. For instance a call to a Nalimov tablebase lookup can only be programmed in "so many ways". And you need to establish what parts of the original program is actually in the public domain etc. Food for thought, I hope!

Igor's picture

The problem is that for AFC to work you need the cooperation of both authors. You actually need the source code. How do u imagine to do AFC with assembler code and how many decades would you like to take to do that. But Rajlich will never do that, for a simple reason he has not debunked the 50 points in the icga decision. I mean you watched the video, his defense is VERY VERY VERY thin. I actually think this video convinced even more people that he is guilty.

Despicableme's picture

When will chessbase adress this issue?
They cannot act as if nothing happened , they should be discussing this news too.

hc's picture

That argument is completely irrelevant. He admits to taking code from Crafy which is mostly certainly not in the public domain. End of story.
If Crafty got the code originally from public domain, then why didn't he do the same? Copying code wholesale from Crafty, which he admits to, is definitely wrong and illegal.

skybon's picture

You can keep "almost certainly" to yourself. Crafty re-used PD code, Rybka re-used PD code and everything is legit. End of story.

Merlinovich's picture

@christos
Your belief that all source code that can be read, is in the public domain, is quite simply wrong. Open source is not necessarily public domain, and Crafty and Fruit are not public domain.

@Igor
Admitting that Crafty and Fruit and Rybka have common calls to e.g. Nalimov tablebases which in general might be considered public domain, is not admitting guilt. If he copied code for calls to this functionality, how could his program Rybka suddenly be "non-original work" when that apparently doesn't apply to Crafty or Fruit? The point is that these calls were already in the public domain, so it didn't matter if he copied it from Crafty or any other source.

Let Crafty and Fruit prove they have completely original programs that did not borrow any ideas from any other program, then let the innocent throw the first stone! The point is that all good chess programs today are heavily building on "the shoulders of giants", and copying from each other, so the "originality" requirement of ICGA is simply void.

What can be used is the definition of copyright itself. The specification of copyright states that ideas can't be copyrighted, only the representation of them. So in fact the prosecutor has a task of proving beyond reasonable doubt that *not only* ideas were copied to Rybka from Fruit and Crafty. ICGA failed to do so in my opinion.

@Ashish - yes everyone does it. And every chess programmer has a disassembler nowadays. Rybka has been disassembled since 2004. Ask yourself why.

Thorn's picture

I think his argument is, that he only took code from Crafty/Fruit which these programs themselves had taken from public domain. Thus, although the took them from Crafty/Fruit, he could also have taken them from other non-GPL sources.

Whethter this is actually true or not is a different question, of course.

christos (greece)'s picture

Yes, public domain is every thing whose source code Vasik Rajlich can read.
So Crafty and Fruit are public domain.
They may have licences attached to them, stating what one can do and what one cannot do with the source code, but who cares to read those licences?

sab's picture

"Once our tournament entry is approved, there’s no grounds at all for reversing course and applying some kind of retroactive penalties."

Well, may be there was no term of limitation. Could someone tell me if I am wrong about that ?

"Why is Rybka being singled out?"

Because by stating that Strelka 2.0 beta was a Rybka 1.0 beta clone when in the meantime Fruit author Fabien Letouzey said it was a Fruit derivate with some minor changes, you [Rajlich] make some programmers curious about Rybka's similarities to Fruit.

Once again, if anyone think I am wrong...

"By the time I was asked to address the accusers and discuss the topic with them, which was again not at all a proper protocol, by this point they had themselves made multiple public statements."

Wonder what could have been a proper protocol.

So let's sum this up.
1) He is against post tournament investigations and retroactive penalties which could result. Sounds like he did something bad and now thinks it is too late to penalize him.
2) He does not want to be the single one accused. Seems like he did something bad but believes to be not the only one.
3) He does not recognize the ICGA protocol because they made an accusation against him based on public results of many seemingly fair investigations : he does not want to be judged since too many programmers (competitors or not) demonstrated he cheated.
4) Asked about the effect of the negative publicity, Rajlich said he had a nice little spike of sales : he does not care about cheating issues as long as he gets money in return.

It will be interesting to see if after another program will win the next ICGA World Computer Chess Championship, Rajlich will continue to get "a nice little spike in sales" assuming ChessBase will continue to sell Rybka.

Igor's picture

OMG, just watched the interview. He doesn't seem to understand that open source and public domain are two different things. When he states he took code from Crafty, he basicly admits the fraud, since crafty is open source but NOT public domain.

Abbas's picture

If I were him, I'd focus on strengthen my engine. public want strong engine regardless of the origin of its code.

Arjo's picture

yes, and:

... i don't know....
...i don't care...
... haven't read it yet...

he just doesnt seem to care at all

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