A UCI chess engine written in C++23.

This project is somewhat a hobby, it will serve to learn the ropes of chess programming. I also play chess, very humbly; and I was always curious of how the programs work.

I began some years ago, but without time, it never went far. I had only a move generator, a alpha-beta search, and that's almost all. I have now enough time to spend on the program. By luck, reading the forums, I discovered Vice, and the videos. Thay are great, and very instructive. So well, Im following the lessons, and Zangdar came to life. I found also the site from Bruce Moreland that explain a lot of things.

Why Zangdar ? Well look for the Naheulbeuk dungeon !!

I would like to thank specially the authors of Vice, TSCP, Gerbil. They helped me a lot understand several aspects of programmation. I also use the M42 library for generating attacks; and took inspiration from the Libchess library.

Since then, I learned a lot, and Zangdar became a formidable opponent. It is now in the first 100 programs, and this represents a big achievement. I would never thought come this far some years ago.

It has the following features :

• Language

  • Written in C++23

• Board

  • Magic Bitboard

• Search

  • Aspiration Window
  • Iterative Deepening
  • Alpha-Beta, Fail Soft
  • Quiescence
  • Killer Heuristic
  • Transposition Table, with 4 buckets
  • Null Move
  • Late Move Pruning
  • Razoring
  • Internal Iterative Deepening
  • Uses several Histories

• Move Ordering

  • MVVVLA
  • Capture History

• Parallelism

  • can use several threads

• Evaluation

  • Since version 3, Zangdar uses a network based on NNUE.

• NNUE

  • The network is relatively simple, 768 Hidden Layer, no bucket.
  • The first one was created with the HCE version of Zangdar. Successives versions were created with the precedent version.

• Syzygy Tables

  • Use of endgame tables is possible; you must use the UCI option. You also need a SSD to work correctly.

• Communication

  • UCI
  • Options to change Hash size, Threads number, Syzygy tables usage, Move Overhead.

• Usage

  • The program is only an engine, so it needs one interface (Arena, Banksgui...).
  • I provide binaries for Windows. I develop with Linux, but as binaries are not portable, I don't distribute it. A Makefile is given and should work without too much work. All are compiled in static, so you don't need extrernal libraries.

• Compilation

  • You must have a C++ compiler that use at least C++23. I use now MSYS2 for Windows 11, that compiles with clang++. I provide also binaries for several architectures.

• Old Releases

  • As I was very ignorant of git, the first repositery was extremely bad done. So I decided to redo it, and uses git tools. But the ancient one is still here, named Zangdar_0.