Overview

Named after the first king of the Franks and the paleoamerican mammoth slayers, Clovis is a powerful UCI chess engine written in C++. It is a successor to Hopper Chess in that it follows standard convention more closely.

Installation

Binaries

Releases

Build from source

Clovis requires make and a compiler with C++20 support.

git clone https://github.com/jonathanmcdermid/Clovis
cd Clovis
mkdir build
cd build
cmake ..
make
./Clovis

Commands for the engine can be issued using the standard UCI format

Strength

Rankings

Clovis is currently estimated to have an Elo rating of ~2880

• CCRL 40/15 Clovis III 2860 Elo
• CCRL Blitz Clovis III 2852 Elo

Technical Details

Board Representation and Move Generation

• Bitboards
• Magic Bitboards
• Move Generation

Search

• Negamax
• Principal Variation Search
• Quiescence Search
• Iterative Deepening
• Transposition Table
• Pawn Hash Table
• Aspiration Windows
• Internal Iterative Deepening
• Reverse Futility Pruning
• Null Move Pruning
• Static Exchange Evaluation
• Late Move Reductions
• Killer Heuristic
• Countermove Heuristic

Evaluation

• Piece Square Tables
• Tapered Evaluation
• Texel's Tuning Method
• King Safety
• Outposts
• Pawn Structure
• Mobility

Credits

This engine uses ideas from various sources

Engine Inspirations

• Stockfish
• Ethereal
• BBC
• Blunder

Resources

• Chess Programming Wiki
• TalkChess Forum
• CCRL
• Cute Chess

Special thanks to the engine testers!