February 6, 2006

Contents & License

In this package, you will find the Rybka 1.0 Beta chess engine (dated Dec 4, 2005), as well as the Turk opening book by Djordje Vidanovic. Both versions of these components are free and can be used and transmitted without restriction.

Overview

This package is intended to be a free introduction to the Rybka engine. If you like the engine and would like to upgrade to the full commercial version, you can do so at our web site:

www.rybkachess.com

Rybka 1.0 Beta engine

FAQ

What is Rybka?

Rybka is a UCI chess engine. It can be used in any UCI-compliant graphical user interface to play chess games and analyze chess positions.

What is a graphical user interface, and where can I get one?

The leading UCI-compliant graphical user interfaces, in no particular order, are:

1) Arena
2) Chessbase / Fritz
3) Chess Assistant
4) Chess Partner

Arena is free. It can be downloaded from the following location:

http://www.playwitharena.com/download/arena199beta2.zip

How do I use Rybka in one of these user interfaces?

The same way you use any chess engine. After installing and starting the chosen interface, the Rybka engine itself must be installed, and then set to be the default engine. Analysis and game play can then proceed as normal for that interface. The exact steps for this vary depending on the interface. By March 1, 2006, graphical instructions for these steps will be available from our website (www.rybkachess.com). Until then, please consult the documentation that comes with your user interface of choice.

What is Rybka 1.0 Beta?

Rybka 1.0 Beta is an older release of the Rybka engine (dated Dec 5, 2005). The version has been widely tested - you will find it on many computer chess rating lists, and it even saw action at the IPCCC in Paderborn at the end of December 2005.

Why should I update to the commercial version?

The commercial Rybka 1.2 version, expected in late February 2006, includes three further months of full-time development work on the engine. The following is a brief list of improvements that were added in those three months:

1) More efficient search
2) Improved endgame heuristics
3) Endgame tablebase access
4) Support for all major UCI & UCI2 features
5) Improved stability and robustness
6) More configurable engine parameters, allowing users to create different personalities of the engine
7) Persistent hash tables, allowing the engine to remember its analysis
8) Separate tactical analysis modes, which specialize in quickly finding clear, decisive, tactically-based solutions
9) A number of various bug-fixes

The commercial Rybka 1.2 version also includes the commercial Rybka opening book, by Jeroen Noomen.

How much stronger is the commercial Rybka 1.2 version than the Rybka 1.0 Beta version?

It is best to leave such questions to the testers. There have been signficant enhancements since Beta 1 to the algorithms which determine playing strength. However, the Rybka 1.0 Beta version does give a fairly good introduction to the style and general approach of the engine.

How much more useful is the commercial Rybka 1.2 version than the Rybka 1.0 Beta version for analysis?

The Rybka 1.2 version will have a number of additional analysis features which should make it attractive as an analysis tool. These include:

1) All basic UCI & UCI2 analysis support, starting with multiple variation mode
2) Intelligent preservation of analysis, so that when positions are re-visited during a second analysis, the original work of the engine is remembered and instantly recalled. This preservation is kept even accross different analysis sessions.
3) A number of tactically-focused analysis modes which find tactical solutions more quickly

Will this Rybka 1.0 Beta version expire after a certain time or constantly ask me to update to the commercial version?

No.


Turk opening book

The Turk opening book included with this package has been created and hand-tuned by Djordje Vidanovic. It is in ".ctg" format, so it can only be used with the Chessbase family of graphical user interfaces.

FAQ with Djordje

How does this book differ from your Rybka Paderborn book?

This book is slightly bigger than the Paderborn book. Besides, it is not as deterministic as the Paderborn book, meaning that it offers more leeway for the choice of moves to the program. It is slightly guided (moves marked in green), and has about 335,000 positions. 

What are the book's strong points?

I believe that the book's strong points could be its sharpness and, hopefully, its congruence with Rybka's playing style. 

What are the book's weak points?

Again, its overall sharpness and its depth that may prove counter-productive. 

What opening books can you recommend for other user interfaces (ie. Arena, etc)?

I haven't enough data regarding other interfaces. I might recommend the Gandalf book that runs in the Lokasoft interface. It may be the strongest of all I've seen. I find the Fritz 9 book very strong too and I believe that Alexander Kure has done a very good job there. 

What other opening books can you recommend for the Chessbase interfaces?

Any future book by Jeroen Noomen :-) 

How should one use the Turk?

In [Edit, Openings book, Book options] please check book options "Use book" and "Tournament book", set variety of play only one mouse click to the right (about one fifth of the slider), influence of learn value about one mouse click to the left starting from the extreme right on the slider, and learning strength at zero (slider completely at the left) unless you would like to enable book learning, which might be counter productive in the long run. Set minimum games to 1, and maximum moves to 40. 



