Suppose the worst case against Vas, and then...

[Uri Blass]

For the discussion both books may have 200 pages when only
10 pages(pages 1,4,6.10-12,34,87,123,145) of Fernando have equivalent pages in the new book or almost equivalent pages.

No accident because one page may have 10 sentences and it is no accident if they have the same content except things like different names of the heros or some very small modifications.

Uri

Are you serious ?

Somebody ACCIDENTLY wrote the same 10 pages in his book ?

You really believe this is possible ? You don't deny the presence of the same lines, you just say: Yeah, that's to be expected.

Well, thank you for explaining the situation very clear for Fernando. Maybe he can tell how likely it is that his new book will have 10 pages the same as a different book (not his own).

Tony

I did not claim that it is the case with rybka and fruit
I only said that the worst case from Vas point of view is equivalent to the case that I suggest.

I do not know if there is some illegal similiarity between rybka and fruit
but I consider people as innocent if I am not convinced that they are quilty.

Uri

Well, then you're right.

If you accept 10 pages of a book being the same as normal, then yes, Rybka is not related to Fruit.

Oh, wait, 10 pages is only 5 %, well 20% is also acceptable. It's only 40 pages from a 200 pages book. But it would have to be the 40 unimportant pages.
The other 40 pages don't count. They are translated, so that's completety rewritten, and therefore unique.


Tony

I did not claim that I accept 10 or 40 pages out of 200 to be the same but only explained the worst case that mean that Vas is quilty .

I think that there is a reason to expect more similiarity between chess programs relative to books so you need more than 5% of chess program
to be equivalent to the case of 5% of a book.

My point is that in the worst case the author is quilty but he is less quilty than the example that people suggested.

Uri

What example ? Wich people ?

Tony

I meant to the following post by Steve B:

"something tells me my friend..that if this were the case..and another writer took a " good part" of your work...gave you no credit..and went on to sell one million copies..made the NY TIMES best seller list and won the Pulitzer prize..never once mentioning you or your work...and you discovered by accident that this great novel was really from your work
you would have a team of Lawyers on this guy so fast it would make the OJ Simpson case look like a University debating squad meet

Case Closed Regards
Steve"


The difference is that Vas did give credit to Fabien without admitting that he took from fruit source and Steve B did not say that only small part of the great novel is copied from Fernando.

[tiger]

For the discussion both books may have 200 pages when only
10 pages(pages 1,4,6.10-12,34,87,123,145) of Fernando have equivalent pages in the new book or almost equivalent pages.

No accident because one page may have 10 sentences and it is no accident if they have the same content except things like different names of the heros or some very small modifications.

Uri

Are you serious ?

Somebody ACCIDENTLY wrote the same 10 pages in his book ?

You really believe this is possible ? You don't deny the presence of the same lines, you just say: Yeah, that's to be expected.

Well, thank you for explaining the situation very clear for Fernando. Maybe he can tell how likely it is that his new book will have 10 pages the same as a different book (not his own).

Tony

I did not claim that it is the case with rybka and fruit
I only said that the worst case from Vas point of view is equivalent to the case that I suggest.

I do not know if there is some illegal similiarity between rybka and fruit
but I consider people as innocent if I am not convinced that they are quilty.

Uri

Well, then you're right.

If you accept 10 pages of a book being the same as normal, then yes, Rybka is not related to Fruit.

Oh, wait, 10 pages is only 5 %, well 20% is also acceptable. It's only 40 pages from a 200 pages book. But it would have to be the 40 unimportant pages.
The other 40 pages don't count. They are translated, so that's completety rewritten, and therefore unique.


Tony

I did not claim that I accept 10 or 40 pages out of 200 to be the same but only explained the worst case that mean that Vas is quilty .

I think that there is a reason to expect more similiarity between chess programs relative to books so you need more than 5% of chess program
to be equivalent to the case of 5% of a book.

My point is that in the worst case the author is quilty but he is less quilty than the example that people suggested.

Uri

What example ? Wich people ?

Tony

I meant to the following post by Steve B:

"something tells me my friend..that if this were the case..and another writer took a " good part" of your work...gave you no credit..and went on to sell one million copies..made the NY TIMES best seller list and won the Pulitzer prize..never once mentioning you or your work...and you discovered by accident that this great novel was really from your work
you would have a team of Lawyers on this guy so fast it would make the OJ Simpson case look like a University debating squad meet

Case Closed Regards
Steve"


The difference is that Vas did give credit to Fabien without admitting that he took from fruit source and Steve B did not say that only small part of the great novel is copied from Fernando.

You can't expect to be exempted from GPL requirements just by giving credits to the original author.

We are not talking books, novels or whatever here. We are talking about a source code protected by the GPL.



// Christophe

[tiger]

Fern is right!

None of this would be talked about without Rybka being the best engine in the world. When I started reading some of these post I just couldn't believe how people could even think this way. What a bunch of haters, but I guess this is what the world is about these days.

Peace and love must be just a silly concept.

[/quote]



We are in the process of showing evidence.

If it is true that Rybka 1.0 is a derived work from Fruit 2.1, and thus infringing on the GPL license, what kind of example you think it is for the future?

The number one is an example. There is no doubt Vas is the best chess programmer at the moment.

With great power comes great responsability.

Please have a look at this. If you do not program yourself, please show it to a fellow programmer:

http://pagesperso-orange.fr/ct_chess/Fr ... rt_go.html

(thanks to Norman for the comparison)



// Christophe

[tiger]

Again, steve, you are falling in a logical fallacy as much you suppose from the beginning that a copy exist, precisely what must be reasoned and probed.
But in fact what worry me is this:
WHAT A HECK ARE YOU AND ME DOING HERE, EVEN DISCUSSING ISSUES, INSTEAD OF BEING TALKING FRIENDLY MATTER IN HIARCS?

Suddenly awaken regards
Fern

You have asked an interesting question because many people could rely on their "common sense" to make their mind about the problem being discussed, and it gave me an opportunity to explain that common sense does not apply. GPL does.



// Christophe

[chrisw]

Again, steve, you are falling in a logical fallacy as much you suppose from the beginning that a copy exist, precisely what must be reasoned and probed.
But in fact what worry me is this:
WHAT A HECK ARE YOU AND ME DOING HERE, EVEN DISCUSSING ISSUES, INSTEAD OF BEING TALKING FRIENDLY MATTER IN HIARCS?

Suddenly awaken regards
Fern

You have asked an interesting question because many people could rely on their "common sense" to make their mind about the problem being discussed, and it gave me an opportunity to explain that common sense does not apply. GPL does.

// Christophe

Why would anyone, other than the most prissy don't-walk-on-the-grass rule follower, care less if the piece of code that passes something from the interface to the chess engine works in a similar manner?

People are interested in whether the engines work in a similar manner and contain cut 'n paste, one to the other.

So far, the only piece of code that goes anywhere near the engine that has been shown here can easily be dismissed as 'implemention of similar ideas', all perfectly legal, GPL or otherwise, by three people, all engine programmers at one time or another.

[Terry McCracken]

Again, steve, you are falling in a logical fallacy as much you suppose from the beginning that a copy exist, precisely what must be reasoned and probed.
But in fact what worry me is this:
WHAT A HECK ARE YOU AND ME DOING HERE, EVEN DISCUSSING ISSUES, INSTEAD OF BEING TALKING FRIENDLY MATTER IN HIARCS?

Suddenly awaken regards
Fern

You have asked an interesting question because many people could rely on their "common sense" to make their mind about the problem being discussed, and it gave me an opportunity to explain that common sense does not apply. GPL does.

// Christophe

Why would anyone, other than the most prissy don't-walk-on-the-grass rule follower, care less if the piece of code that passes something from the interface to the chess engine works in a similar manner?

People are interested in whether the engines work in a similar manner and contain cut 'n paste, one to the other.

So far, the only piece of code that goes anywhere near the engine that has been shown here can easily be dismissed as 'implemention of similar ideas', all perfectly legal, GPL or otherwise, by three people, all engine programmers at one time or another.

You of all people should take greater responsibility in this matter.

The evidence provided thus far should give you pause.

[kranium]

Why would anyone, other than the most prissy don't-walk-on-the-grass rule follower, care less if the piece of code that passes something from the interface to the chess engine works in a similar manner?

People are interested in whether the engines work in a similar manner and contain cut 'n paste, one to the other.

So far, the only piece of code that goes anywhere near the engine that has been shown here can easily be dismissed as 'implemention of similar ideas', all perfectly legal, GPL or otherwise, by three people, all engine programmers at one time or another.

source code concerning UCI is part of the engine
it is not separate
if it is part of the source code, it is subject to the GPL
what has been posted is far from an implementation of similar ideas,
-there is identical (equivilent) code, and a substantial amount of it.

i wasn't aware that only cut 'n paste of the 'engine' was wrong.
are you saying: the 'non-engine' (whatever that is) is fair game...because people are not interested?

i feel confident that most will not 'dismiss' the evidence so quickly...

[chrisw]

Why would anyone, other than the most prissy don't-walk-on-the-grass rule follower, care less if the piece of code that passes something from the interface to the chess engine works in a similar manner?

People are interested in whether the engines work in a similar manner and contain cut 'n paste, one to the other.

So far, the only piece of code that goes anywhere near the engine that has been shown here can easily be dismissed as 'implemention of similar ideas', all perfectly legal, GPL or otherwise, by three people, all engine programmers at one time or another.

source code concerning UCI is part of the engine
it is not separate
if it is part of the source code, it is subject to the GPL
what has been posted is far from an implementation of similar ideas,
-there is identical (equivilent) code, and a substantial amount of it.

i wasn't aware that only cut 'n paste of the 'engine' was wrong.
are you saying: the 'non-engine' (whatever that is) is fair game...because people are not interested?

i feel confident that most will not 'dismiss' the evidence so quickly...

For the purposes of "computer chess", poeple who are interested in engines are going to be much more interested in engine cut 'n paste than they are in issues of the UCI. The icga tournament coming up will not be interested in the UCI if an attempt is made to get Rybka disqualified, they'll, want to know about the engine, only.

Over a week ago I asked here for proof that the relevent UCI sections were actually covered by the GPL, since chunks of UCI code in any program for many years will have been developed outside the GPL and before its use as a licence for Fruit. Do you know which bits are and which bits aren't? I doubt it.

[Steve B]

The difference is that Vas did give credit to Fabien without admitting that he took from fruit source and Steve B did not say that only small part of the great novel is copied from Fernando.

Ferns "worst case scenario" posed that "a good piece " was taken from Fruit..not a small part
so this is what we are hypothetically discussing
secondly,,,when was Fabien given credit?
IIRC there was only some obscure Internet interview in which Vas mentioned that some ideas were gleamed from Fruit but i think this interview was well after the release of R1 and sometime well into the marketing and sales of R2
please indicate if credit(no matter how small or vague) was given to Fabien BEFORE the release of R1 and /or R2..
Steve

[Eelco de Groot]

(Answer to Steve:)

Many people were given credit by Vas:

Rybka v 1.0 Beta Readme
Dec 4, 2005


Thanks for agreeing to become a beta taster for Rybka 1.0. Rybka is a standalone UCI chess engine which can be installed and run in any chess graphical front-end which supports that protocol. If this last sentence is cryptic to you, it is probably better that you wait until the fully documented and user-friendly Rybka 1.0 release in the middle of December 2005.

Brief Engine Specs

History: The Rybka chess engine began as a part-time project in March 2003 and is now being developed full-time.

Aims: Rybka aims to have a fully knowledgeable evaluation function. This term however has taken some abuse recently, so let me make something clear: chess knowledge wins chess games. If it doesn't, it isn't knowledge.

Opening book: Not supported. An internal engine opening book contradicts my sense of the proper separation between the database-oriented graphical front end and the engine. However, if enough people scream for this, well ..

Winboard support: Ditto - not supported. This protocol contradicts my notion of what an engine should do. However, if enough people scream for this ...

Endgame tablebase support: In principle, this also slightly contradicts my notion of what an engine should do. Chess strength comes from themes and principles, not memorization. However, enough people have screamed for this and so endgame tablebases will be supported in the full Rybka 1.0 release.

Multi-processor support: Not present in Rybka 1.0, but at the top of the to-do list for the next release. The emphasis will be on running smoothly on the affordable multi-core desktop machines which are revolutionizing the personal computer world.

Beta Distribution

We ask that the beta releases not be circulated except in cases where special permission was given, as it was for example to all of the members of the CEGT test team. Those interested in becoming beta testers are asked to please contact us directly to get a copy.

Release Dates

Dec 2, '05: windows 64-bit Rybka 1.0 Beta
Dec 4, '05: windows 32-bit Rybka 1.0 Beta
Dec 16, '05: Rybka 1.0

64-bit & 32-bit releases

Rybka 1.0 represents the internal chessboard using bitboards - one bit for each square on the board. Bitboards are nothing new - they date back to publications from the Soviet Union in the 1970s - and the topic is a source of endless discussion on the computer chess message boards. After 30+ years, we still have no idea if bitboards are the most efficient way to represent chess knowledge.

For the users, there is one serious practical effect: like other bitboard engines, and unlike non-bitboard engines, Rybka runs significantly faster on 64-bit systems than on 32-bit systems. For example, the following are the knps rates for the two versions of the engine on my own test position sample on a 2.4 GHz Amd-64 machine:

32-bit Rybka 1.0 Beta: 104 knps
64-bit Rybka 1.0 Beta: 166 knps

This difference in speed should result in a difference in strength of between 25 and 50 rating points. I believe that it should be relatively bigger at shorter time controls, and relatively bigger in sharper openings (ie. Sicilians) rather then in more strategic openings (ie. Nimzowitch, French). The computer chess community does not have very good data about this topic and I would be very pleased if some testers investigated it further.

Testers are also of course free to decide for themselves how (if at all) to distinguish these two different playing strengths.

User Features in Full Release

The Beta releases are missing several features which will be present in the full release. These features are related to user friendliness and have no effect on practical playing strength, so it is appropriate for Rybka 1.0 Beta versions to represent Rybka 1.0 in rating lists. These features include:

1) Full support of UCI protocol ("go nodes", "go mate", "go searchmoves", etc)
2) Multi-variation mode
3) Tablebase support (I should say that it is only my personal opinion that tablebases are not a playing strength feature - others may disagree)
4) Proper handling and reporting of mates

Beta Testing

In practice, Beta testing usually means Beta using. It certainly has meant that in my experience as a Beta tester Nevertheless, we are interested in all kinds of feedback. In particular, we are interested in:

1) Testing under all sorts of different conditions - different operating systems, different machines, different GUIs, against different opponents, playing on ICC or playchess, etc.
2) Statistically valid game-playing results, again under all sorts of different conditions.
3) Comments about playing style or strength or even better, annotated games, potentially for use on our web site (which is under construction).
4) Feedback about the "search direction" option, see section below for more details.

Closer Collaboration?

We are also interested in finding chess and computer chess fans who would like to participate more closely in our project. There are a number of possibilities in this direction:

1) Opening book creation.
2) Official operation of Rybka in in-person and online tournaments.
3) More serious and technically open testing of Rybka versions and changes.
4) Porting of the engine to other platforms.

Please contact us if you are interested in any of the above.

I should also mention one other thing: we are planning to expand the project to include a GUI which can properly display Rybka's chess knowledge. This will probably also involve expanding the UCI protocol - but that's all another topic for another day. In general I prefer to work with people I have worked with in the past, under deadline pressure, etc. Nevertheless, if you are a talented software developer with an interest in computer chess, don't hesitate to get in touch with me.

"Search Direction" UCI Option

In general, chess strength is chess strength - each component of an engine either makes it stronger, or weaker. At this point, it appears that there is one potential exception to this in the case of Rybka, so I have decided to make it a user option. The name of the option is "search direction", and there are four possible settings:

1) Very Positional
2) Slightly Positional
3) Slightly Tactical
4) Very Tactical

The default setting is very positional. This is the version which I like the best personally, and the setting also makes the most sense to me intuitively. It vibes with the way I think search should be handled and where the priorities should be placed. In addition, a 350 game head-to-head match at 40/10 time control gave the following result:

Rybka 1.0 (Very Positional): 193.5
Rybka 1.0 (Very Tactical): 156.5

However, the very positional version gives slightly inferior results on tactical testsuites. On a private tactical testsuite which I use, I got the following result:

Rybka 1.0 (Very Positional) was faster: 11
Same depth: 30
Rybka 1.0 (Very Tactical) was faster: 56

Of course, tactical testsuites are a dicey business, but the above is a significant result and it also agrees with my intuition regarding what should happen. (That's why I use the names I use for these versions.)

In addition to these tests, each version also played a 150-game match against Shredder 9. I'll keep the exact scores secret (that's what testers are for), but the very tactical version scored 2.5% better than did the very positional one. This itself is not that impressive for a 150-game match, but given the head-to-head result, it does raise some questions. The most likely explanation is that more games would flatten this phenomenon into nothing, but one could also theorize that Rybka is relatively better positionally than Shredder anyway and any tactical weakness just opens the door for Shredder's powerful search. If so, it might further turn out that this phenomenon is limited to games at relatively short time controls.

If any testers out there are looking for a more interesting project, getting to the bottom of this would be extremely interesting for me.

One more note here: the intermediate "slightly positional" and "slightly tactical" settings are almost completely untested by me - no games were played. They represent two more neutral settings between the two tested extremes. There are actually two separate quantities being adjusted internally, so "slightly positional" goes to the tactical extreme on one and the positional extreme on the other (bigger) one, and "slightly tactical" is vice-versa. Hence, it might be that one of these two settings ends up being a sort of magical median - although I doubt it.

Special Thanks

I hesitate to include this section because I know I'll forget people who have been helpful in this project, but (with advance apologies to the omitted) here goes:

Robert Hyatt - For Crafty. There is nothing like an open source program for passing knowledge to the next generation.
Fabien Letouzey - For Fruit, which shattered a number of computer chess myths, demonstrated several interesting ideas, and made even the densest of us aware of fail-low pruning.
Tord Romstad - For making Fabien aware of fail-low pruning , and more seriously for sharing in every way possible his considerable knowledge.
Eugene Nalimov - For his cryptic but somehow fully functional endgame tablebase access code.
Uri Blass, Gerd Isenberg, Dieter Burssner, Vincent Diepeveen, Raschid Chan, Anthony Cozzie, Mridul M* , Thomas Gaksch, Peter Berger, Sandro Necchi, Ed Shroeder, Amir Ban, Christophe Theron and every one else, past and present, on the computer chess club: For sharing their computer chess knowledge despite the fact that in principle computer chess is a competitive field.
Heinz van Kempen, Guenther Simon, Olivier Deville, Sergio Martinez, Claude Dubois: for testing early versions of Rybka despite countless bugs and annoying problems.
Alex Dumov, Gabriel Luca: for helping a Windows newbie get up to around half-speed without excessive derision (or at least open derision )
and Iweta: for being great! and a pretty good Rybka tester and web master to boot

Happy testing, and best chess regards,
Vasik Rajlich
Budapest Hungary
December 4, 2005

By the way, it has been said that a GPL based program would not be legal making use of Eugene Nalimov EGTB code. Neither is including literal parts of GPL based programs, programs explicitly given credit for in the read.me, unless the program is covered by a similar GPL licence. I am sure that Vas would have been aware of this when writing Rybka 1.0 Beta and did take care not to break any GPL.

Eelco