A UCI chess engine with an ultra-aggressive style.
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PRAL333 is a UCI chess engine that analyzes chess positions and computes the optimal moves with an aggressive style profile.
PRAL333 does not include a graphical user interface (GUI) that is required to display a chessboard and to make it easy to input moves. These GUIs are developed independently and are available online. Read the documentation for your GUI of choice for information about how to use PRAL333 with it.
See also the PRAL333 documentation for further usage help.
This distribution of PRAL333 consists of the following files:
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README.md, the file you are currently reading.
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Copying.txt, a text file containing the GNU General Public License version 3.
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AUTHORS, a text file with the list of authors for the project.
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src, a subdirectory containing the full source code, including a Makefile that can be used to compile PRAL333 on Unix-like systems.
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a file with the .nnue extension, storing the neural network for the NNUE evaluation. Binary distributions will have this file embedded.
See Contributing Guide.
Improving PRAL333 requires a massive amount of testing. You can donate your hardware resources by installing the Fishtest Worker and viewing the current tests on Fishtest.
In the chessprogramming wiki, many techniques used in PRAL333 are explained with a lot of background information. The main chess programming references describe many features and techniques used by modern engines. However, they are generic rather than focused on PRAL333's precise implementation.
The engine testing is done on Fishtest. If you want to help improve PRAL333, please read this guideline first, where the basics of chess engine development are explained.
Discussions about PRAL333 take place mainly in the PRAL333 Discord server. This is also the best place to ask questions about the codebase and how to improve it.
PRAL333 has support for 32 or 64-bit CPUs, certain hardware instructions, big-endian machines such as Power PC, and other platforms.
On Unix-like systems, it should be easy to compile PRAL333 directly from the
source code with the included Makefile in the folder src. In general, it is
recommended to run make help to see a list of make targets with corresponding
descriptions. An example suitable for most Intel and AMD chips:
cd src
make -j profile-build
Detailed compilation instructions for all platforms can be found in our documentation. Our wiki also has information about the UCI commands supported by PRAL333.
PRAL333 is free and distributed under the GNU General Public License version 3 (GPL v3). Essentially, this means you are free to do almost exactly what you want with the program, including distributing it among your friends, making it available for download from your website, selling it (either by itself or as part of some bigger software package), or using it as the starting point for a software project of your own.
The only real limitation is that whenever you distribute PRAL333 in some way, you MUST always include the license and the full source code (or a pointer to where the source code can be found) to generate the exact binary you are distributing. If you make any changes to the source code, these changes must also be made available under GPL v3.
PRAL333 uses neural networks trained on data provided by the Leela Chess Zero project, which is made available under the Open Database License (ODbL).