What makes Rybka so strong?

[Hart]

I don't know if the question is taboo or even appropriate but I ask anyways out of sheer inquisitive curiosity. With the sources of Ippolit/RobboLito, so called "clones" of Rybka 3, are we any closer to answering such questions and if we are is it acceptable to discuss such questions in public or are these discussions to remain in dark corners or behind closed doors?

[smcracraft]

A very good question.

The "cone of silence" is deafening.

[mclane]

one cannot see it.

[wgarvin]

The Fool's Errand.

screen shots.

You can still play it today, with a mac emulator for example. Classic game.

[Eelco de Groot]

I don't know if the question is taboo or even appropriate but I ask anyways out of sheer inquisitive curiosity. With the sources of Ippolit/RobboLito, so called "clones" of Rybka 3, are we any closer to answering such questions and if we are is it acceptable to discuss such questions in public or are these discussions to remain in dark corners or behind closed doors?

Yes please,

Can we have a real open source version of Rybka 3 that has been fully commented, and debugged by the whole army of programmers that have inspected Hippo and its clones. Please spend as much time on this as on inspecting the sources. I know that probably is illegal but the way things have gone that would seem the only good thing that could come out of this. It could never enter any official competition of course, except by Vas. Only owners of an official version of Rybka 3 can use it on Playchess, if that is Vas' choice. He will call it Rybka 3+. Intially he wanted to make Rybka 3+ himself but since everybody seems so willing to lend a helping hand and he got a bit sidetracked himself, I can fully understand it if he would actually consider this. Up to him of course.

And please stop with all the bull about Rybka being a clone of Fruit, I think it is really beyond words that you use this as a justification for treating this different from how you would treat any other market leader to which this had been done. Any issues with a breach of the GPL of Fruit should be taken up with the Free Software Foundation and only they could do something about that. Fabien has given them that right.

Regards, Eelco

[mcostalba]

With the sources of Ippolit/RobboLito, so called "clones" of Rybka 3

I am not sure it is _only_ Rybka 3 or even something more, perhaps a beta version of Rybka 4 given that the "thing" seems stronger (I didn't tested in games nor I am interested in doing it, but reading comments here it seems that is even stronger then 3).

It is difficult to say, it is not a single feature but more a bunch of features, admittely very differents then what you can see in open source programs, that seems to make the difference. But each one of that features, taken individually, does not seem to help, even perform sligtly worst.

So I think that the dish is well prepared more because of the recipe then the single ingredients

[Hart]

I don't know if the question is taboo or even appropriate but I ask anyways out of sheer inquisitive curiosity. With the sources of Ippolit/RobboLito, so called "clones" of Rybka 3, are we any closer to answering such questions and if we are is it acceptable to discuss such questions in public or are these discussions to remain in dark corners or behind closed doors?

And please stop with all the bull about Rybka being a clone of Fruit, I think it is really beyond words that you use this as a justification for treating this different from how you would treat any other market leader to which this had been done.
Regards, Eelco

Where do you see me justifying anything on the grounds of Rybka being a clone of Fruit? If you meant this generally then be a little more careful how you mix your accusatory tone with words like "you".

[Hart]

My guess is that it is not more than 30 Elo stronger than R3 if it is stronger at all. From some matches I played at CCRL 40/4-like time controls:

Code: Select all

Rank Name                                       Elo    +    - games score oppo. draws
   1 Rybka 3 64-bit 4CPU                       3265   11   11  3902   80%   178   28%
   2 Rybka 3 Dynamic 64-bit 4CPU               3264   24   23   811   81%   179   28%
   3 Rybka 3 64-bit 2CPU                       3227   15   15  2154   81%   129   26%
   4 RobboLito 0.085c                          3202   45   44   163   59%   292   40%
   5 Rybka 3 64-bit                            3177    9    9  7198   79%    96   25% 

I had just assumed that if somebody had the time and knowledge to convert a binary file of a chess engine to C then they are probably smart enough to improve it in certain places. If the C code is 14,000 lines and guessing that every line of C is translated to (say) 5 hardware instructions, then picking through 70,000 lines of hardware instructions should give you the knowledge of where low level optimizations might be more beneficial.

[Eelco de Groot]

I don't know if the question is taboo or even appropriate but I ask anyways out of sheer inquisitive curiosity. With the sources of Ippolit/RobboLito, so called "clones" of Rybka 3, are we any closer to answering such questions and if we are is it acceptable to discuss such questions in public or are these discussions to remain in dark corners or behind closed doors?

And please stop with all the bull about Rybka being a clone of Fruit, I think it is really beyond words that you use this as a justification for treating this different from how you would treat any other market leader to which this had been done.
Regards, Eelco

Where do you see me justifying anything on the grounds of Rybka being a clone of Fruit? If you meant this generally then be a little more careful how you mix your accusatory tone with words like "you".

Sure Michael, it was meant as a general comment to the discussion. Just posted what I felt. If my "gut-feeling" comments were not thought through I apologize, I sure hope somebody can come up with a better idea If you took it personally I apologize to you Michael and I see nothing wrong with the question that you posed, at least I think I would like to know myself just as much as you do, what makes Rybka strong But I suppose that is not all this can be about, not the only consideration?

Eelco

[Don]

I don't know if the question is taboo or even appropriate but I ask anyways out of sheer inquisitive curiosity. With the sources of Ippolit/RobboLito, so called "clones" of Rybka 3, are we any closer to answering such questions and if we are is it acceptable to discuss such questions in public or are these discussions to remain in dark corners or behind closed doors?

I don't believe there is anything special in Rybka, it's just the program as a whole that is special. I think you will be disappointed if you believe there is some secret that Vas is keeping in the closet somewhere.

I looked at the sources of IPP and the only thing that stood out to me is that it is probably more selective than most or all programs that are really strong, but I did not see any special mechanism for doing this, just the same type of stuff we are doing anyway. Vas is just doing it better.

Another thing that stands out to me is that it is has an excellent evaluation function. It may be the best evaluation function of any of the programs, yet it is still probably weaker in some areas than some other good programs. I have heard that king safety is one of the weak points, although it is improved over the previous versions.

There is no secret in Rybka that you can just transfer over to your program in a few minutes and then expect to compete with Rybka.


- Don