Chess Engines

RubiChess – chess engine written in C++

RubiChess is a very strong UCI-compliant chess engine. The Universal Chess Interface (UCI) is an open communication protocol that enables chess engines to communicate with user interfaces.

This engine started in 2016 as a private hobby project to practise programming in C++ and to see the engine improving compared to earlier releases.

RubiChess is published under an open source license.

Features include:

  • Uses magic bitboards (about 24% faster than rotated bitboards) to determine sliding piece attacks.
  • Search functionality:
    • Lazy SMP (1.3).
    • Iterative Deepening.
    • Aspiration Windows.
    • Alpha-Beta.
    • Principal Variation Search.
    • Transposition Table.
    • Selectivity:
      • Null Move Pruning with Verification.
      • Late Move Reductions.
      • ProbCut (1.3).
      • Futility Pruning.
      • Extended Futility Pruning.
      • Late Move Pruning.
      • Reverse Futility Pruning.
      • Razoring.
      • Singular Extensions.
      • Quiescence Search.
      • SEE Pruning.
      • Delta Pruning.
    • Move Ordering:
      • PV-Move.
      • Internal Iterative Deepening.
      • Captures by MVV/LVA.
      • Static Exchange Evaluation.
      • Killer Heuristic.
      • History Heuristic.
      • Counter Moves History.
  • Evaluation:
    • NNUE (RubiChess NNUE).
    • Texel’s Tuning Method.
    • Tapered Eval.
    • Material.
    • Piece-Square Tables.
    • Mobility.
    • Rooks on (Semi) Open Files.
    • Hanging Pieces.
    • Pinned Pieces.
    • Pawn/King Hash Table.
    • Pawn Structure:
      • Phalanx.
      • Passed Pawn.
      • Candidate Passed Pawn.
    • King Safety:
      • Attacks.
      • Pawn Storm.
    • Tempo Bonus.

Developer: Andreas Matthies
License: GNU General Public License v3.0

RubiChess is written in C++. Learn C++ with our recommended free books and free tutorials.

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