Rybka 1.0 vs. Strelka

[chessfurby]

It is well known fact. That is why those who knew it all the time are not worshipping Vas or rybka for that matter. However if you speak out loud you get silenced by the knights guarding the holy grail...

Cheers

[bnemias]

Any speculative development project (for example developing a chess engine) by a competent developer, will include detailed analysis of the competition. Since some of the competition publishes source, any developer is going to take a good look at that too. All design process starts with analysis. Programmer looks at everything and thinks, "hmmm, I can do better".

Since published source also provides a testbed environment, the idea that it is not general for programmers (inexperienced at start, and in a huge, complex project such as chess engine) won't use such a generally available testbed environment to get up and running beggars belief. It is not illegal in any way to do so, all that matters is that the end result If any) has thrown away all the original published material.

Of course not _everybody_ develops this way. Some may well start from scratch, it used to be (pre 1990's) that everybody had to start from scratch - hence fewer programs then and lots now.

I wrote a quite strong Shogi program once. It took two months. My GUI programmer modified the CSTal user interface which mostly involved dealing with the change in board size, the artist gave him some shogi piece graphics, I gutted the CSTal engine, rewrote the move and genmove stuff, reused search with lots of the fancy stuff removed and wrote an evaluation function based on the Tal evaluation. If thatI'ld been done that within equivalent GPL code? Well the next task would be to take the Shogi specific engine modules, which by definition all work, and wrap them into an entirely new interface. Voila - an entirely squeaky clean product, all one's own work.

Anyway, quite why do you feel the need to describe this development mechanism as an "accusation". It's a sensible and entirely legal way to progress. It saves time, there'll be fewer bugs and the chances that the whole thing doesn't just fall apart through complexity is reduced. If the result is for release or publication then that's fine, as long as there is nothing of the original in place. my 2c.

I'm not sure I understand your point. You are saying it's a natural and normal development process to perform a complete rewrite between beta and release versions? And you are saying that process results in _fewer_ bugs?

[chrisw]

Any speculative development project (for example developing a chess engine) by a competent developer, will include detailed analysis of the competition. Since some of the competition publishes source, any developer is going to take a good look at that too. All design process starts with analysis. Programmer looks at everything and thinks, "hmmm, I can do better".

Since published source also provides a testbed environment, the idea that it is not general for programmers (inexperienced at start, and in a huge, complex project such as chess engine) won't use such a generally available testbed environment to get up and running beggars belief. It is not illegal in any way to do so, all that matters is that the end result If any) has thrown away all the original published material.

Of course not _everybody_ develops this way. Some may well start from scratch, it used to be (pre 1990's) that everybody had to start from scratch - hence fewer programs then and lots now.

I wrote a quite strong Shogi program once. It took two months. My GUI programmer modified the CSTal user interface which mostly involved dealing with the change in board size, the artist gave him some shogi piece graphics, I gutted the CSTal engine, rewrote the move and genmove stuff, reused search with lots of the fancy stuff removed and wrote an evaluation function based on the Tal evaluation. If thatI'ld been done that within equivalent GPL code? Well the next task would be to take the Shogi specific engine modules, which by definition all work, and wrap them into an entirely new interface. Voila - an entirely squeaky clean product, all one's own work.

Anyway, quite why do you feel the need to describe this development mechanism as an "accusation". It's a sensible and entirely legal way to progress. It saves time, there'll be fewer bugs and the chances that the whole thing doesn't just fall apart through complexity is reduced. If the result is for release or publication then that's fine, as long as there is nothing of the original in place. my 2c.

I'm not sure I understand your point. You are saying it's a natural and normal development process to perform a complete rewrite between beta and release versions? And you are saying that process results in _fewer_ bugs?

Not at all. The version containing test bed code that had to be replaced would not conventionally be called a beta and I didn't call it that, it's your supposition. And yes, it results in fewer engine bugs for the simple reason that the engine development can be tested within the testbed as the code is written. For an amateur programmer unused to the level of complexity of a chess engine it's invaluable to be able to test modules inplace rather than write them, not be able to fully test them, put them all together and then deal with all the interelating bugs that weren't picked up. There's more potential bugs in chess engine development than anyone could possibly imagine.

[Olivier Deville]

Here is my main concern with respect to copying/cloning/etc. I have been doing this for almost exactly 40 years now. I started competing in the ACM events in 1976. It was pretty brutal at the top, with chess 4.x, chaos, duchess, Belle, etc being mature programs. But at the bottom and middle, it was still a fight. Nobody had any advantage over anyone else, and so we all felt as if we could compete and improve. Had someone been able to copy (say) chess 4.x and use it back then, most of us would probably have dropped out as the playing field would have been tipped to the "copy crowd" rather than being equalized, and many would have been discouraged and quit.

Today, new ideas come from amateurs all the time. If they are driven away because it is impossible to compete with a "fresh program" then we all lose something in the bargain.

I think it important that newcomers can write a program, and compete, without having to compete against the same program multiple times in a single tournament. I though Jakarta in 1996 (or 1997) was wrong because it had two copies of Crafty in, mine, and one the University (sponsoring entity) entered. Those two programs finished in either 3rd and 4th or 4th and 5th places. And it didn't seem fair.

I can't speak for others, but for me, that is the issue that causes concern. Simple fairness. Not envy. Not anger. Not anything but wanting to compete fairly with anyone that cares to join in. I have won WCCC and CCT events. I'm still the only two-time (consecutive) WCCC winner in fact. I've won several CCTs. And so have others. And that competition is a lot of fun. It is less fun when you start competing against multiple copies of the same program, or the same professionally-prepared opening book, etc...

Hi Bob,

this is a post that I respect. Well stated.

Cheers, Graham.

I second that.

If everything would be allowed, we would end up with dozens of Fruits and Rybkas and other chimeres in the tournaments.

In this case I would certainly choose another hobby than testing engines.

Olivier

[Enir]

Hi Chris,

[snip]

Fabien says he has no problem.

Where did Fabien say it? This is of key importance in the whole issue.

Enrique

It's a bit convoluted, but the argument of the "Rybka 1.0 beta might be a clone camp" goes like this ...

Strelka is a reproduction of Rybka 1.0 beta.
Strelka resembles Fruit at a programming level
Therefore Rybka 1.0 resembles Fruit.

The "Rybka 1.0 beta protection society" argues:
Fabian has no worries with Strelka.
If other side wants to argue Strelka = Fruit
then Fabian by extension also has no problems with Rybka.


Bob wrote:
Didn't Vas clearly post "Strelka is a reproduction of Rybka 1.0 and I am claiming it as my own code now"??? I saw that specific comment (probably not those exact words, but semantically _identical_ posted by him when the Strelka / clone issue first broke.

Dan Corbit wrote:
This is what Fabian said about Strelka:
"No worries as far as I am concerned.
Ideas are not a legal property.
The code was rewritten so it's OK with me.
Tournament organisers might think differently.
I cannot say a definite yes or no ..."

Some programmers found code similarities between Strelka and Fruit; Vasik said that Strelka was R1 beta; Fabien told Corbit that he didn’t mind about Strelka. When was all that?

I’m asking because I would like to know why these accusations take place now and not in the old times of Rybka 1 beta. And whether they are related to other accusations here last week about Rybka giving R2 for free and not showing the true node count. I’m not saying it’s a campaign, but it might very well look like it, with these three simultaneous accusations against Rybka just before China 2008 and immediately after the huge lead of Rybka 3.

By the way, when Vasik said that Strelka was R1 beta, was he referring to the whole program or to parts of it? If to parts of it, the whole accusing syllogism (part of Str = Fr, part of Ry = Str, therefore Ry = Fr) is false, because Strelka could have copied parts of Rybka code different than Fruit. Possible? I'm asking you as programmer. I'm lay.

As for your "Tournament organizers might think differently", Rybka 3.x will play in China, not R1 beta, so I don’t see on which grounds the organizers could object.

Enrique

OK, last point first. If you find the first crafty version available, which would now be over 10 years old since it was released in 1995 somewhere, and if you take today's source and diff them. You would find far more than 50% of the code is duplicated. yes the eval has changes. Yes _parts_ of the search has changed. And yes, parts of the move generator have changed. But, if I had "borrowed" that original version of Crafty from someone else, and it had been GPL'ed when I borrowed it, today's version of Crafty would be an illegal copy. The GPL is specific, once you start with GPL code, your code is GPL until _every last line_ has been rewritten so that not one single line of GPL code remains. It is not much of a stretch to believe that R2 has much of the same source as R1. And that R3 has much of the same source as R2. So _if_ R1 is a partial or complete copy of fruit, R1 is automatically GPL code. And unless R2 was 100% rewritten, R2 would also be GPL. Ditto for R3.

Guesswork. Many "would", "if", "unless", "believe" in your writing above. Tournament organizers cannot base any decisions on guesswork, educated or not. Reverse engineer R3 and prove that GPL code from the non commercial R1 beta still exists in Rybka 3. The rest is mere assumption, and one doesn't accuse based on assumptions.

Enrique

Next, (and by the way, I didn't point out the claim by Vas, CT quoted it and suddenly a "warning light" started blinking as I had just not given this much thought) we do not have the source of R1. But we have a direct statement by Vas that Strelka was a copy of R1, that the source for Strelka was written by reverse-engineering the assembly language in the Rybka 1 executable. And he then claimed that "strelka is my code, and I will now distribute it as such." So we have a direct tie from strelka to Rybka.

Finally, a few have started to compare strelka to fruit, and have found marked similarities, and lots of identical code that is shared between both. So this establishes a link from strelka to fruit.

So we end up with a direct connection from fruit -> strelka -> rybka 1, with the probable connection of Rybka 1 -> Rybka 2 -> Rybka 3.

And all of that is, to me, troubling. Programs are supposed to be original works Not modified copies. Otherwise things I (and others) have complained about in the past suddenly become moot. I can think of Gunda 1 Jakarta, then Le Petite, Voyager, bionic impact and others that I have forgotten about, but all of which were direct copies of Crafty, and all of which created a lot of discussion and all of which were ultimately declared clones, not allowed into tournaments, etc. With that past history, plus others trying to clone programs dating as far back as Chess Genius, it looks to be problematic. And now we have yet another potential derivative work rather than original work.

I have not been involved in discovering this, I have followed the discussions, and have stated several times that based on the evidence that has been presented, things appear to be a bit off-color. Since the Rybka group are offering no arguments or evidence to the contrary, it would be hard to draw any other conclusion.

That is where things stand, and how they have reached the current point. For the people that have been absolutely caught red-handed, I consider them to be the lowest form of morally-challenged con artists. The current case has not yet reached that point. But it is moving in that direction until something convincing shows up to counter the current mountain of evidence. It would be nice to have a "counter-point" here and there that is factual. 90% of the comments are nonsensical and useless for helping to resolve this.

[bob]

I started from absolute scratch in 1968

pretty amazing Bob. In 1968 i was 2 years old !
unbelievable !!

I was a junior in a university, newly married. The department chairman thought it was amazing as well.

[bob]

I think the thing that disturbs me most about all this is the timing.
It certainly gives the appearance that because Vas released Rybka 2.2 as a free engine, this is payback from a lot of pissed off programmers.

I personally don't even know what you are talking about there. What is "free"? And why would it piss anyone off?

Didn't Ed do this with Prodeo? I don't remember anyone getting pissed off back then?

[bob]

[quote

I'm not a programmer and so all this code being produced means little to me.
However, from what I've read, it seems that no matter what is said, there will still be disagreement amongst more knowledgeable people than myself over what constitutes absolute proof of anything untoward.
What I would be interested in is what those like yourself, Bob and Zach are therefore trying to achieve. What exactly is it that you want as the end outcome?

Regards, Graham.[/quote]

"Bob" has not been trying to achieve anything. I have provided two opinions in all of this mess.

1. why one would obfuscate program output.

2. that the similarities between Rybka and Strelka, posted by several others, is beyond what one would call "luck". I based my opinion on this on 38 years of teaching, and grading student programming assignments that range from 10-20 lines of code to well beyond 2,000 lines. I've done this long enough to have a pretty good feel for how much similarity will naturally exist between two large programming assignments.

My only goal is to do whatever can be done to prevent cloning/copying, otherwise chess development and competition is going to become just a "giant clone event"... And new programmers are going to avoid chess because it will be so hard to start from scratch to try something new, and still be competitive.

[Olivier Deville]

You are assuming too much. For example, would you file suit against someone that was making a claim that hurt you, if you_knew_ that the claim was true? Because to file the suit, you have to make a sworn statement that the claim is false in order to seek damages. And if the claim is later proven true, you just committed perjury and are now looking at prison time rather than seeking financial redress from someone else. The sword of justice cuts both ways so caution is required.

I could cut out the other stuff because this here already shows your bias. You simply argue always from the position that Vas has done something wrong. I already wrote a message to write my astonishment how experts could be biased. If you at least would find arguments in favor of Vas, just out of principle. Or also in case you knew how something might have no legal relevance.

Has Vas responded in any way about this? How can one find points in his favor if there is nothing but a deafening silence from his side of the table???

I think he can rely on a purely psychological standpoint for the moment. When did you talk to a commercial programmer collegue during the last 50 years? Now that's going too far. You are looking upon everything like the guy with a hammer. Everything looks to him like a nail while hidden nails frighten him. A commercial programmer cannot discuss what he does, Bob, he lets his program speak. He's in chess what you are on ICC in Bullet. Simply the best!

Sorry, but that boat won't float. When I was accused of cheating several years ago, about something that happened back in 1986. I chose to not sit idly by and let the accusations reverberate around r.g.c.c... I replied factually, quoted a specific letter from David Levy which described the investigation he did and the conclusion that absolutely nothing wrong was done, and so forth. It would be easy enough to simply post "Rybka is my own unique work, I didn't borrow any code form any GPL or open-source programs, so I don't know why this kind of discussion has come up." I can think of only one reason why _I_ would not write that were the discussion about me, I'll leave discovering that reason as an exercise for the reader. I think it is obvious enough that anyone will "get it."

Maybe so. Maybe not. CCC is not ICGA and no one has the obligation, moral or not, to defend from accusations on a forum. It is also possible to look down to them and tell oneself "they bark, so I ride". 2001: been there, done that.

Several people in the last days implicitly accused Vas of copyright breaching. Implicitly. I still have to see an open, unambiguous accusation like "Vas copied Fruit, is a plagiarist and breached Fabien's copyright." Maybe Vas is waiting for this?

Enrique

Hi Enrique

Such a statement would be deleted by the moderators.

Olivier

[bob]

Care to claify?

Your last comment was absurd in this case.

Why? I wondered how legal it is for anybody to openly declare that they're disassembling the exe of an engine and then posting the results of their handiwork for the world to see.

If you make it available, that is a risk you take. The only protection is to apply for a patent to protect the idea from reverse-engineering. Since that has not been done, there is no legal issue regarding what has been done.