mattgodbolt / rengar

Chess engine with a simple evaluation function written in C++

Rengar

A chess engine with a simple evaluation function written in C++. Play me on lichess!

Features

Search techniques

• Alpha beta pruning
• Iterative deepening
• Quiescence search
• Transposition tables
• Null move reductions
• Late move reductions

Move ordering

• Killer heuristic
• Guard heruistic
• Piece square tables

Evaluation

• Piece square tables
• Mobility
• Tapered evaluation
• Tempo bonus

Make targets

• release, the default, will compile the engine binary
• tune will optimize move order parameters for accuracy on a specified set of games
• unit will compile and run unit tests via doctest
• perft will run validation checks on move generation code

Self-play

To compare across different versions:

• Compile the engine from different branches
• Run a tournament with analysis/selfplay.py, specifying the opening book, the time control, and the list of branches