TalkChess.com

It appears to me that Vas has made some disappointing choices.

However, I suspect that every single person who has ever made a chess program has carefully examined someone else's source and read someone else's article and implemented their own version of it.

Maybe Vas's use was more extensive, but he has been given the death sentence for the same thing that every other chess programmer does. Simply put, it is necessary to use modern techniques like LMR, Null move, PVS search, etc. I guess further that not a single programmer here has invented all of his evaluation terms, but at least got ideas from other programmers, GMs, etc.

An algorithm is not protected by copyright. If you read and understand an algorithm, you can make your own implementation of it. There is nothing wrong with that. I guess that nobody here really understands what that means, considering how people react. Do people really not understand what the definition of an algorithm is?

I also do not think that plagiarism has any bearing on the subject. Vas was not producing a published report, and he also did give credit to both Crafty and Fruit, stating that he had carefully studied them. It does seem to me that he did take excessive liberties, but still I think it is strange to talk about plagiarism for a chess engine binary. Plagiarism is an academic crime.

I really do not know for sure how much wrongdoing Vas has done, but I think to a large degree he was made a whipping boy for the same sins that all chess programmer commit.

Shredder was not reverse engineered. Hiarcs was not reverse engineered, Junior was not reverse engineered. Because of Vas' ultimate success he was singled out. Was it petty jealousy?

My whole take on this can (of course) be completely wrong. But I feel deep disappointment on all sides of the argument.

IMO-YMMV

I find it strange that your post doesn't contain the word "code" even once.

rbarreira wrote:I find it strange that your post doesn't contain the word "code" even once.

All of the code used to commit Vas is from reverse engineering.

Have you seen the post I made some time ago that showed two completely different code bases in C produced identical assembly (even the control structures were different).

Vas has been convicted of stealing code in a court made up of his opponents. There is literally no Rybka code available.

From assembly, the only thing that can be demonstrated is the algorithm similarity. I recall that 64% similarity was a quoted figure somewhere.

I am not a programmer but that was well said Dann.

rbarreira wrote:I find it strange that your post doesn't contain the word "code" even once.

I do want to make it clear that I do not absolve Vas completely.

However, I think what has been done to him is disgraceful.

Dann Corbit wrote:It appears to me that Vas has made some disappointing choices.

However, I suspect that every single person who has ever made a chess program has carefully examined someone else's source and read someone else's article and implemented their own version of it.

Maybe Vas's use was more extensive, but he has been given the death sentence for the same thing that every other chess programmer does. Simply put, it is necessary to use modern techniques like LMR, Null move, PVS search, etc. I guess further that not a single programmer here has invented all of his evaluation terms, but at least got ideas from other programmers, GMs, etc.

An algorithm is not protected by copyright. If you read and understand an algorithm, you can make your own implementation of it. There is nothing wrong with that. I guess that nobody here really understands what that means, considering how people react. Do people really not understand what the definition of an algorithm is?

I also do not think that plagiarism has any bearing on the subject. Vas was not producing a published report, and he also did give credit to both Crafty and Fruit, stating that he had carefully studied them. It does seem to me that he did take excessive liberties, but still I think it is strange to talk about plagiarism for a chess engine binary. Plagiarism is an academic crime.

I really do not know for sure how much wrongdoing Vas has done, but I think to a large degree he was made a whipping boy for the same sins that all chess programmer commit.

Shredder was not reverse engineered. Hiarcs was not reverse engineered, Junior was not reverse engineered. Because of Vas' ultimate success he was singled out. Was it petty jealousy?

My whole take on this can (of course) be completely wrong. But I feel deep disappointment on all sides of the argument.

IMO-YMMV

+1

Zagalo wrote:

Dann Corbit wrote:It appears to me that Vas has made some disappointing choices.

However, I suspect that every single person who has ever made a chess program has carefully examined someone else's source and read someone else's article and implemented their own version of it.

Maybe Vas's use was more extensive, but he has been given the death sentence for the same thing that every other chess programmer does. Simply put, it is necessary to use modern techniques like LMR, Null move, PVS search, etc. I guess further that not a single programmer here has invented all of his evaluation terms, but at least got ideas from other programmers, GMs, etc.

An algorithm is not protected by copyright. If you read and understand an algorithm, you can make your own implementation of it. There is nothing wrong with that. I guess that nobody here really understands what that means, considering how people react. Do people really not understand what the definition of an algorithm is?

I also do not think that plagiarism has any bearing on the subject. Vas was not producing a published report, and he also did give credit to both Crafty and Fruit, stating that he had carefully studied them. It does seem to me that he did take excessive liberties, but still I think it is strange to talk about plagiarism for a chess engine binary. Plagiarism is an academic crime.

I really do not know for sure how much wrongdoing Vas has done, but I think to a large degree he was made a whipping boy for the same sins that all chess programmer commit.

Shredder was not reverse engineered. Hiarcs was not reverse engineered, Junior was not reverse engineered. Because of Vas' ultimate success he was singled out. Was it petty jealousy?

My whole take on this can (of course) be completely wrong. But I feel deep disappointment on all sides of the argument.

IMO-YMMV

+1

-1 :- )

Dann Corbit wrote:

rbarreira wrote:I find it strange that your post doesn't contain the word "code" even once.

I do want to make it clear that I do not absolve Vas completely.

However, I think what has been done to him is disgraceful.

What is disgraceful is the fact that you totally skip over the copy-and-paste of CODE. Rajlich has not re-written algorithms, he has copied and pasted code, which can be shown by the presence of dead code that cannot be explained otherwise.

At some point I could have interpreted your comments as a lack of competence. After all you are the one who declared after looking at the code that there were no simiarities between Strelka and Fruit or Rybka, and that Strelka looked really new and original.

Now you are suggesting that it's not Rajlich. It's the compiler. The compiler took source code written differently and produced the same object code. That's a line of defense that is still not going to explain the presence of dead code taken verbatim from Fruit or Crafty sources.

Dann maybe you should take a little break from this. Your credibility has been in the red zone for a long time now, and you are making it look even worse.


// Christophe

I strongly agree with your thoughts. In my eyes, the liberties that Mr. Rajlich appears to have taken even seem quite irrelevant.

We don't want clones because we feel that the inventor of an original algorithm should enjoy its success. So it would be great if we could detect if engines copy essential algorithms of their competitors. In fact, we can: All engines copy the key algorithms of all competitors, and as soon as a new idea like LMR enters the realm of open source engines, many of us try if they work well in the context of our own engine. So in this sense, most chess engines are clones from the algorithmic pioneers in the most crucial sense.

If the evidence against Rybka is factually correct, then the only evidence "beyond" this copying of ideas is evidence of copying actual code. Indeed, useless identical code segments strongly indicate that something has been copied. Considering the amount of time one uses to tune a chess engine, it would not have been hard for the author of Rybka to avoid this by rewriting instead of copying. This would have had no effect on the originality of its algorithms, but would have removed the evidence of the code transfer. Personally, I don't care if someone copies or rewrites code.

In short: We are all guilty of cloning in the essential sense, and catching someone at superficial cloning is interesting only from a technical point of view. From a human point of view, I am very disappointed in the way in which people many of whom I had considered honourable, flock together to lynch the reputation of someone who has been their prime competitor.

Feuerstein wrote:I am very disappointed in the way in which people many of whom I had considered honourable, flock together to lynch the reputation of someone who has been their prime competitor.

This is very true. Those with a herd mentality would do well to remember that in no way does it legitimise their "efforts".

3000 elo engines are like buses, there will be another one along in a minute..... Mostly they break down though. Lack of parts (and mechanics) is a big problem.



Chris