Nawito-22.07 - Cuban Chess Engine by Ernesto Torres

Engine version: 22.07
Release date: 31-07-2022
Available versions: Windows/Linux/Android (64 bits)
Communication protocol: UCI
ELO estimated: 2690
License: GPL
email: NawitoChessEngine@yandex.com
github: https://github.com/etorresf/Nawito64Bit

TABLE OF CONTENTS

1. General description
2. Content
3. Performance
4. Features
5. License
6. Credits

1. GENERAL DESCRIPTION

Nawito-22.07 is a free Cuban chess engine derived from Danasah5.07 compatible with the UCI protocol. To get the most out of it, it should be used under a graphical user interface (GUI) like: Arena (Linux/Windows), Winboard (Windows), Xboard (Linux), Pychess (Linux/Windows), SCID (Linux/Windows), DroidFish (Android), Chess for Android (Android) and others.

Its author has been based on the search function of the Danasah5.07 engine and inspired in other
(TSCP, CPW, Rebel, Mini Rodent, Fruit, others). To develop your own ideas and give it a particular style.

It is develop with free tools and open source code, under C language and Clang compiler. Available versions for: Windows, Linux, Android.

Nawito use the polyglot opening book scheme, with the internal engine hash key synchronized to this schemes.

Please report any ideas, suggestions or errors about the engine.

2. CONTENT

• README.md
  This file
• GPL-LICENSE.txt
  Engine license
• history.txt
  Release notes
• /Windows
  • Nawito-22.07-windows-x64.exe
    Engine for Windows (64 bits)
  • Nawito.ini
    Configuration file of Windows engine
  • logo.jpg
    Logo of Windows program (by Dusan Stamenkovic)
• /Linux
  • Nawito-22.07-linux-x64
    Engine for Linux (64 bits)
  • Nawito.ini
    Configuration file of Linux engine
  • logo.jpg
    Logo of Linux program (by Dusan Stamenkovic)
• /Android
  • Nawito-22.07-arm7-x64
    Engine for Android (64 bits)
  • Nawito.ini
    Configuration file of Android engine
  • logo.jpg
    Logo of Android program (by Dusan Stamenkovic)
• /src
  Program code
  • Makefile
    Program compilation manager
• /Books
  Chess engine opening books (polyglot format)
• /EvalParam
  Configuration of evaluation parameters
• /Logos
  Various logos of the engine

3. PERFORMANCE

• perft
  Command to discover faults or measure move generator speed to the depth (by default 5)
  from this position: r3k2r/p1ppqpb1/bn2pnp1/3PN3/1p2P3/2N2Q1p/PPPBBPPP/R3K2R w KQkq -
• bench Command to check the relative speed of the computer with respect to another.
  Solve mate from this position: r4nk1/4brp1/q2p1pQP/3P4/2p1NP2/P7/1B6/1KR3R1 w - - 1 34

4. FEATURES

• Protocol
  • UCI
• Board representation
  • Bitboard
• Move Generator
  • Bitboard
• Search
  • Aspiration window
  • Iterative depth
  • PVS/Alpha-Beta
  • Quiescence
  • Internal iterative deepening (IID)
  • Reductions/Prune
    • Checkmate distance
    • Null moveme
    • Transposition table
    • Futility
    • Razoring
    • Captures
    • Late Move Reductions (LMR)
  • Extensions
    • Check
    • Checkmate threat
    • Pawns end
• Move ordering
  1. PV
  2. Transposition table
  3. MVV/LVA
  4. Killer heuristic
  5. Historical heuristic
• Evaluation
  • Tapered eval
  • Material
    • Piece material
    • Knight decreasing value as pawns disappear
    • Rook increasing value as pawns disappear
    • Bishop pair
  • Pawns struct
    • Backward pawn
    • Advanced pawn
    • Candidate pawns
    • Doubled pawns
    • Isolated pawn
    • Passed pawn
  • King seafty
    • King seafty
    • King shield
    • King tropism
  • Mobility
    • Knight mobility
    • Bishop mobility
    • Rook mobility
    • Queen mobility
    • Traped pieces
      • Traped knight
      • Traped bishop
      • Traped rook
      • Outpost knight
    • Bad bishop
    • Rook in open o semi-open file abierta
    • Rook in 7th
  • Endings (KPK, KBNK, KRK, KBBK, KRPKR, others)
  • Tables due to insufficient material
  • Others
• Time management
  • conventional
  • incremental
  • fixed time per movement
  • fixed time per depth
• Opening Book
  • Polyglot opening book scheme
• Others
  • Detection of the end of the game with the rules of FIDE, including triple repetition and 50 movements rule

5. LICENSE

This program is free software: you can redistribute it and/or modify it. Under the terms of the GNU General Public License as published by the Free Software Foundation, be it the version 3 of the License, or (at your option) any later version

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. Watch the GNU General Public License for more details

You should have received a copy of the GNU General Public License along with this program If not, see http://www.gnu.org/licenses/

6. CREDIT

I am very grateful to the following people:

• To my family and friends, who are always there to help
• To all those who have decided to share the source code of their engines (I have clarified functions and understanding of them)
• To Pedro Castro for the search function of his DanaSah engine. For your cooperation and for clarifying legal issues regarding chess engines
• To the CPW website http://chessprogramming.wikispaces.com for all the content on the techniques applicable to a chess engine
• To the web ajedrezmagno http://ajedrezmagno.cubava.cu for disclosing and providing information about Nawito
• To Dusan Stamenkovic for make a logo for Nawito
• To all those who have played with the engine and have published their experience and opinions