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Raubfisch: Updated March, 31 2019




Raubfisch is an engine derived from Stockfish and Torpedo 1.1 XJR (private engine by Frank Karl Werner and Max Fehler)


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21/01/19 poll average perc.: 8.65.



Actual versions: Raubfisch X40 cluster and GTZ19 cluster.





Maximize its strength by using my opening book Goi.


Instructions of use:

* The options ICC_Analysis and Clear_Search are in the experimental phase, and they are dedicated to the chess players by correspondence.

  ICC means International Correspondence Chess.

*Deep_Analysis is an additional option to "Analysis_ICC. It can often solve positions that Analysis_ICC option can not do.

Always do the following order:

- Stage 1 : First uncheck "Null Move Heuristic", then check "Analysis ICC" and start your position analysis. If after a time you feel long, you have not find satisfaction in your search, stop the analysis.

- Stage 2 : Check in more "Deep Analysis_ICC" and "Clear search" and start the analysis of the position.

To illustrate the above, here is an example of position which has been resolved by Deep_Analysis_ICC but not by Analysis_ICC!

8/5p2/8/8/p7/rpK4p/1p3ppr/bQ1N1bqk w - -

The screenshot below shows that Raubfisch could not solve the given above position


Below is an example of the same position solved by setting Deep_Analyis ICC:


>> For example, if you want to analyze a difficult position with Raubfisch X series, check "Analysis ICC", and uncheck "Null Move Heuristic". Then validate your settings and launch the analysis.

* "Vielfalt" means Diversity of lines (moves) , which may be useful during the analysis of a game played or other... (Correspondence chess games)
*-Tune-- > Null move search/dynamic reduction based on depth and value ---

*NullSearchDepthFactor = 38
*NullSearchValue = 249
*NullReductionDepthValue = 1000
*NullReductionDepthFactor = 66
*NullReductionDepth = 256
*NullReductionPawnValue = 200

** Tune-- > Extension search

ExtensionSearchDepthFactor1 = 19,
ExtensionSearchValue1 = 177,
ExtensionSearchDepthFactor2 = 80,
ExtensionSearchValue2 = 1

According a 1200 games test, we see stable values in a range between 1.025 and 2, in the following ratio r:

r = abs[(-ExtensionSearchDepthFactor1+ExtensionSearchValue1)/(-ExtensionSearchDepthFactor2+ExtensionSearchValue2)]
Either 1.025 <= r <= 2.
The above values give a ratio of the order of 2.0, which seems to offer Raubfisch, a rather interesting balance between aggressiveness and security.
* Analysis Opt : The option Analysis optimism, called "Analysis Opt" is enabled by default on "Both". This means that white and black pieces will be simultaneously overvalued in an infinite analysis.
This option can bring an advantage during a search of mate position. However it is recommended to disable this option by selecting "Off" during a deep analysis of position.


* Adding Save/Load Hash File Capability of saving the full hash to file. This option code was written by Daniel Jose and improved by Max Fehler.

To save the hash, stop the analysis and click on the "SaveHashtoFile" button in the uci options screen of the GUI.

To load the hash file, load the game you saved and you want to continue Analysis, load the engine without starting it, and press the "LoadHashfromFile" button in the uci options screen of the GUI. Now you can start the analysis.

For example saving the full hash to file with Raubfisch X36d1:

* Opening Books

How to use classical book.bin option in Raubfisch engine ?

Raubfisch can use Polyglot opening books. When playing with a book, Raubfisch will move instantly if it finds a legal move leading to a position in the book.
Start by renaming your book by book1.bin . Then copy the book1.bin book to the same directory you put the your Raubfisch executable in.
Also, make sure that Book1 UCI option is checked, and that "Book1File" is also set to book1.bin.
The option “Best Book1 Line” when set will make Raubfisch play the best scoring book move, or randomly select between two or more book moves with the same score.
When off, it will tend to play the best scoring move more often, but still give the weaker moves some play.

Note that the instructions for use of the book 1 is equally valid for book 2.



The simultaneous use of three books with Raubfisch

* Raubfisch is an engine that can combine the use of tree books at the same time; that is to say two books.bin (one book1.bin Book and one book2.bin) and one book.ctg at the same time!
This gives you the possibility when the engine do not find the legal move in the 1st book and, if it is in the 2nd book or 3rd book, it will play automatically.
It is a definite advantage in a tournament or during your workouts in the engine room.


Raubfisch X single processor benchmark:




Raubfisch GTZ single processor benchmark: