Fruit 2.1 vs Strelka 2.0

[geots]

I disagree about the 40-50% and it may be something like 10-20%

No similiarity in the move generator that is a significant part of strelka.
No extremely similiar code in the evaluation function that is also important part(there may be similiar ideas about evaluation but not similiar code and strelka has special code for material imbalance tables).

I do not understand how do you get at least 40-50% similiarity.

The functions that you post are clearly less than half of the code of strelka.

Uri

10-20% of similarity -- does that makes a program clone of other?

We are not at all talking about cloning.

I'm afraid this word (clone) is totally out of place in the current discussion.

We are looking at the similarities. If there are similarities then the question is: could such similarities happen in programs that have been written independently?



// Christophe

Nobody claims that strelka and fruit have been written independently
Learning from other programs is certainly legal.

You can say that the similiarity is too much but it is not clear what is the limit of too much.

I use average between opening score and endgame score based on stage of the game in Movei and I learned the idea from Fruit(I did not use it before fruit)

This similiarity is not something independent of fruit and I guess that most new programs are based on some ideas that the author learned from fruit.

Uri

Fine but we are not looking at the re-use of ideas here.

We are looking at the re-use of source code.

If you believe that the similarities are limited to the use of the same ideas, then you should look at the comparisons of source code that have been posted.



// Christophe

I do not claim that the similiarity is limited to the same ideas but I understood that they are not enough for Fabien to consider Strelka as something like toga.

Uri

Hi Uri-

I distinctly remember that a few days ago, Dann Corbit posted Fabiens email response after Fabien reviewed Strelka source code...unfortunately, it was in the 'washed' thread, so it can't be referenced here, but in essence, Fabien's reply was something to the effect of: 'oh well, it's been re-written', and 'i cannot say yes or no' ...

clearly, this is not approval, he's caught between a big rock and hard place.

Norm

I disagree very, very much. Clone is not "out of place" in this discussion. Simply because for me, all this technical stuff is no doubt way over my head. Im just a tester, and you guys lose me with the first sentence in these threads. What IS IMPORTANT for me would be fi Bob, Ingo, Uri, Theron, etc. would tell me where we exactly stand now with the Strelka-Fruit- Rybka issue. IOW, is it still more or less agreed the Strelka is a clone- and i guess im asking "illegal" clone of something- to the point where CCRL should still not be testing it- as we did stop?

Best,

Would one or more of the above mentioned people please answer this for me. I am not trying to be difficult or cause trouble. This is very important to me!

Best,

[Harvey Williamson]

Hi George,

Without getting involved in the broader debate Strelka should be totally removed from your ratings list.

Best Wishes,
Harvey

[geots]

Hi George,

Without getting involved in the broader debate Strelka should be totally removed from your ratings list.

Best Wishes,
Harvey

Thanks Harvey, for your opinion.

Best,

[Zach Wegner]

OK, I'm not one of the mentioned persons, but I feel I am enough of an "expert" in this matter...

What IS IMPORTANT for me would be fi Bob, Ingo, Uri, Theron, etc. would tell me where we exactly stand now with the Strelka-Fruit- Rybka issue. IOW, is it still more or less agreed the Strelka is a clone- and i guess im asking "illegal" clone of something- to the point where CCRL should still not be testing it- as we did stop?

In my completely honest opinion, I would say that Rybka is under serious doubt with regards to its origin. There are some similarities that have been discovered, beyond just the simple protocol parsing code, that are just way too much to be a coincidence IMO. I will note that though I have reverse engineered a relatively small amount of Rybka, but everything that I have has matched with Strelka and had remarkable similarities to Fruit. Some have said that we are running a smear campaign without any evidence, but it is coming out. More and more will gather. There is still not proof (and it is of course debatable whether we would be able to prove anything), but there are questions that IMO demand an official response.

I'm not sure about the legalities of the issue, but I'm inclined to believe that Strelka is more legitimate than Rybka (1.0 at least).

I don't know what to think about Rolf's comments. They make no sense at all really. We have tried to present as much and and as solid evidence as possible. Of course, the type of evidence is such that it is not easily understood by a "lay". But we're not simply creating things in order to confuse the non-programmers. Not one programmer has spoken up against the evidence I posted a bit earlier, nor any in this thread

I think that those that know me here can tell that I'm not doing this out of envy--nothing could be further from the truth. I feel that an injustice is being committed, and that since it is against an open source program (I am a big open source advocate, for those that don't know), I feel a personal responsibility to try to get to the bottom of this--not to simply defame someone.

[geots]

OK, I'm not one of the mentioned persons, but I feel I am enough of an "expert" in this matter...

What IS IMPORTANT for me would be fi Bob, Ingo, Uri, Theron, etc. would tell me where we exactly stand now with the Strelka-Fruit- Rybka issue. IOW, is it still more or less agreed the Strelka is a clone- and i guess im asking "illegal" clone of something- to the point where CCRL should still not be testing it- as we did stop?

In my completely honest opinion, I would say that Rybka is under serious doubt with regards to its origin. There are some similarities that have been discovered, beyond just the simple protocol parsing code, that are just way too much to be a coincidence IMO. I will note that though I have reverse engineered a relatively small amount of Rybka, but everything that I have has matched with Strelka and had remarkable similarities to Fruit. Some have said that we are running a smear campaign without any evidence, but it is coming out. More and more will gather. There is still not proof (and it is of course debatable whether we would be able to prove anything), but there are questions that IMO demand an official response.

I'm not sure about the legalities of the issue, but I'm inclined to believe that Strelka is more legitimate than Rybka (1.0 at least).

I don't know what to think about Rolf's comments. They make no sense at all really. We have tried to present as much and and as solid evidence as possible. Of course, the type of evidence is such that it is not easily understood by a "lay". But we're not simply creating things in order to confuse the non-programmers. Not one programmer has spoken up against the evidence I posted a bit earlier, nor any in this thread

I think that those that know me here can tell that I'm not doing this out of envy--nothing could be further from the truth. I feel that an injustice is being committed, and that since it is against an open source program (I am a big open source advocate, for those that don't know), I feel a personal responsibility to try to get to the bottom of this--not to simply defame someone.

You were actually one of the mentioned persons- just accidentally left out. Certainly your knowledge is right up there with any of them, and i appreciate your answering me. I will admit, however, i really did not want to bring up this Rybka deal again- tho i did mention the program, but not in the context i wanted its origin questioned. But maybe in the eyes of all the above guys- one cannot be addressed without the other. I really dont know. The more i read- the more confused i get.
But again, thank you for answering me.


Best,

[chrisw]

Zach,

Do you seriously imagine Frederik is going to take on publishing Rybka without cast-iron guarantees that it is squeaky clean?

Why risk it?

Do you imagine Vas, if Rybka was just maybe possibly under suspicion, didn't spend all the effort necessary to ensure no possible contamination from other software?

Business is business. Breaches of criminal and/or civil law, unnecessarily, woudl be just dumb. And why woudl it be necessary? Do you imply there isn't sufficient knowledge and capability in the Vas team to be unable to produce independent source code?

Come on.

OK, I'm not one of the mentioned persons, but I feel I am enough of an "expert" in this matter...

What IS IMPORTANT for me would be fi Bob, Ingo, Uri, Theron, etc. would tell me where we exactly stand now with the Strelka-Fruit- Rybka issue. IOW, is it still more or less agreed the Strelka is a clone- and i guess im asking "illegal" clone of something- to the point where CCRL should still not be testing it- as we did stop?

In my completely honest opinion, I would say that Rybka is under serious doubt with regards to its origin. There are some similarities that have been discovered, beyond just the simple protocol parsing code, that are just way too much to be a coincidence IMO. I will note that though I have reverse engineered a relatively small amount of Rybka, but everything that I have has matched with Strelka and had remarkable similarities to Fruit. Some have said that we are running a smear campaign without any evidence, but it is coming out. More and more will gather. There is still not proof (and it is of course debatable whether we would be able to prove anything), but there are questions that IMO demand an official response.

I'm not sure about the legalities of the issue, but I'm inclined to believe that Strelka is more legitimate than Rybka (1.0 at least).

I don't know what to think about Rolf's comments. They make no sense at all really. We have tried to present as much and and as solid evidence as possible. Of course, the type of evidence is such that it is not easily understood by a "lay". But we're not simply creating things in order to confuse the non-programmers. Not one programmer has spoken up against the evidence I posted a bit earlier, nor any in this thread

I think that those that know me here can tell that I'm not doing this out of envy--nothing could be further from the truth. I feel that an injustice is being committed, and that since it is against an open source program (I am a big open source advocate, for those that don't know), I feel a personal responsibility to try to get to the bottom of this--not to simply defame someone.

[Uri Blass]

OK, I'm not one of the mentioned persons, but I feel I am enough of an "expert" in this matter...

What IS IMPORTANT for me would be fi Bob, Ingo, Uri, Theron, etc. would tell me where we exactly stand now with the Strelka-Fruit- Rybka issue. IOW, is it still more or less agreed the Strelka is a clone- and i guess im asking "illegal" clone of something- to the point where CCRL should still not be testing it- as we did stop?

In my completely honest opinion, I would say that Rybka is under serious doubt with regards to its origin. There are some similarities that have been discovered, beyond just the simple protocol parsing code, that are just way too much to be a coincidence IMO. I will note that though I have reverse engineered a relatively small amount of Rybka, but everything that I have has matched with Strelka and had remarkable similarities to Fruit. Some have said that we are running a smear campaign without any evidence, but it is coming out. More and more will gather. There is still not proof (and it is of course debatable whether we would be able to prove anything), but there are questions that IMO demand an official response.

I'm not sure about the legalities of the issue, but I'm inclined to believe that Strelka is more legitimate than Rybka (1.0 at least).

I don't know what to think about Rolf's comments. They make no sense at all really. We have tried to present as much and and as solid evidence as possible. Of course, the type of evidence is such that it is not easily understood by a "lay". But we're not simply creating things in order to confuse the non-programmers. Not one programmer has spoken up against the evidence I posted a bit earlier, nor any in this thread

I think that those that know me here can tell that I'm not doing this out of envy--nothing could be further from the truth. I feel that an injustice is being committed, and that since it is against an open source program (I am a big open source advocate, for those that don't know), I feel a personal responsibility to try to get to the bottom of this--not to simply defame someone.

I do not know why do you think that strelka is more legitimate than rybka1

Strelka2 is more similiar to fruit than rybka1

There are some things that both strelka and fruit has when rybka does not have them like null move verification and if we talk about strelka2.0 unlike strelka1.8 I can say that strelka2 use more simple average of opening evaluation and endgame evaluation based on the stage of the game that is an improvement relative to rybka or strelka1.8 code.

I think also that it is not clear if the similiarity between strelka and fruit is enough to make strelka illegal because of the fruit case(it can be illegal because of rybka but this is a different story).

Strelka is not a clear derivative of fruit like toga when almost everything is the same.

Uri

[Rolf]

OK, I'm not one of the mentioned persons, but I feel I am enough of an "expert" in this matter...

What IS IMPORTANT for me would be fi Bob, Ingo, Uri, Theron, etc. would tell me where we exactly stand now with the Strelka-Fruit- Rybka issue. IOW, is it still more or less agreed the Strelka is a clone- and i guess im asking "illegal" clone of something- to the point where CCRL should still not be testing it- as we did stop?

In my completely honest opinion, I would say that Rybka is under serious doubt with regards to its origin. There are some similarities that have been discovered, beyond just the simple protocol parsing code, that are just way too much to be a coincidence IMO. I will note that though I have reverse engineered a relatively small amount of Rybka, but everything that I have has matched with Strelka and had remarkable similarities to Fruit. Some have said that we are running a smear campaign without any evidence, but it is coming out. More and more will gather. There is still not proof (and it is of course debatable whether we would be able to prove anything), but there are questions that IMO demand an official response.

I'm not sure about the legalities of the issue, but I'm inclined to believe that Strelka is more legitimate than Rybka (1.0 at least).

I don't know what to think about Rolf's comments. They make no sense at all really. We have tried to present as much and and as solid evidence as possible. Of course, the type of evidence is such that it is not easily understood by a "lay". But we're not simply creating things in order to confuse the non-programmers. Not one programmer has spoken up against the evidence I posted a bit earlier, nor any in this thread

I think that those that know me here can tell that I'm not doing this out of envy--nothing could be further from the truth. I feel that an injustice is being committed, and that since it is against an open source program (I am a big open source advocate, for those that don't know), I feel a personal responsibility to try to get to the bottom of this--not to simply defame someone.

Typical answer/view from a programmer, Zach. You are young, you think you must bear no responsibilities and you are inexperienced in life issues.

- the legal aspect is the main point, Zach. But I doubt that you are legally to be held accountable. That's the most important, because in such a freedom granted by CCC you can do many things.

- Zach, you can even do harm to Vas. In the following way: you say you have questions and therefore you must analyse in public (!) what this is all about with Rybka. The point you miss out of lack of life experience is, that yes you have questions but if in the end after everything will be published, you will say no, that doesnt cut it, then there is no zero damage done but the total armageddon for Vas. Can you understand it? Your result could be nothing found but you have still published Rybka so that then all could take it. Of course you didnt want it, because you had only questions. And in the end you will say, ouch, but I didnt know it. I'm still so young and inexperienced.

- this isnt just a smear act as I said, it's also blackmail, after the known scheme: Vas, you can stop "us" at the instant, if you allow "us" to look into your source code, and if we havnt found something illegal then fine for you and for us because then we know at least your secrets.

- because of the almost criminal intent, there wont be commercial programmers in this here - openly. Because they could be held accountable for the mess. As I wrote to Bob, they will take a "10" y. old, well here the possibly youngest around with a minimum of knowledge, Zach. (Just to explain that Zach had given his private data for the moderation elections, therefore I know a bit.)

- BTW it was George who detailed the aspects of such a situation. He said either there is proof for some wrong then sue Vas, but id this about libel, then shut up because in that case you only pretend you want to collect data for aproof but in real it's libel. Of course we wont see programmers with a business, no Europeans and no establishe guys with a career to defend. All that points at the truth that there is no proof. Only libel.

[geots]

I think when all is said and done, Chris Whittington's prior comment really stands out to me. He hit the nail on the head. Whether you like Chessbase or not, they did not get where they are today by making foolish decisions that could ruin them or by being stupid. They would have never touched Rybka with a 10 foot pole if there was ANY chance it could come back to haunt them. Enough said.

Best,

[bob]

I disagree about the 40-50% and it may be something like 10-20%

No similiarity in the move generator that is a significant part of strelka.
No extremely similiar code in the evaluation function that is also important part(there may be similiar ideas about evaluation but not similiar code and strelka has special code for material imbalance tables).

I do not understand how do you get at least 40-50% similiarity.

The functions that you post are clearly less than half of the code of strelka.

Uri

Hi Uri-

you have a point, i have not scientifically measured the percentage in any way shape or form, it was just my estimate. at the same time, i did not post everything. there's quite a bit more...it's clear that the total is a large and substantial amount.

move generators exist in every chess program...i don't think it is any more important in Strelka than any other program.

as I said, many of the non-similar functions are a bitboard implementation, but truly, if you follow them closely, i believe there is a close resemblance to the flow and logic of Fruit.

Norm

'

Uri seems to attach more importance to the move generator than I do. I am more interested in the search and the evaluation, as those are what makes programs different. Generating moves is a constant-in - constant-out operation, because the rules of chess moves are precisely defined. But for search and evaluation there are no "rules".

Move generator is not a constant factor and it has an effect on the search.

Order of generating moves can clearly influence the order of moves so it can have an effeect on the search.

Move generator that has tricks to generate only part of the captures also has some effect on the search.

Uri

That is a minor issue related to performance. The issue here is that for a position P, there is a set of moves m(i) that is constant no matter how you generate moves. You might generate them in a different order. You might generate them all at once, or even one at a time as they are searhed, as chess 4.x and darkthought did. I changed mine from rotated to magic with no other effect on my program... Search and evaluation, on the other hand, is a _big_ deal.