Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

[3.0.0] - 2026-01-30

V3 Engine with GPU/CPU Support:
- device.py - Automatic CUDA detection with CPU fallback
- cuda_kernels.py - Numba CUDA batch evaluation kernels
- parallel_search.py - Thread pool for parallel root search
- chess_transposition_table.py - Thread-safe TT with RLock
Thread Safety:
- Thread-local counters for search statistics
- Locked history and killer move tables
- Thread-safe transposition table with automatic eviction
- Support for 15+ CPU threads on multi-core systems
GPU Acceleration (CUDA):
- Batch position evaluation kernel
- Automatic CPU fallback if CUDA unavailable
- 512MB VRAM budget enforcement
- Memory usage monitoring

V2 Engine Architecture: Complete rewrite with modular design
- chess_engine.py - Core game state and move generation
- chess_algorithm.py - Negascout search with SEE, MVV-LVA, killer moves
- chess_heuristic_calculation.py - Comprehensive evaluation function
- chess_opening_book.py - 50+ opening position database
- chess_transposition_table.py - Position caching
- chess_hash.py - Zobrist hashing for position identification
Modern Web UI: React + Vite frontend with FastAPI backend
- main/client/ - React application
- main/server/ - FastAPI REST endpoints
Comprehensive Evaluation Function:
- Material counting (centipawn values)
- Piece-square tables with tapered evaluation
- Bishop pair bonus (+50 cp)
- Rook on open/semi-open files (+15-25 cp)
- Passed pawn bonuses (up to +150 cp)
- Pawn structure penalties (doubled/isolated)
- King safety (pawn shield, castling bonus)
Search Enhancements:
- Negascout (Principal Variation Search)
- Quiescence search with SEE pruning
- Static Exchange Evaluation (SEE)
- Check extensions
- MVV-LVA move ordering
- Killer moves heuristic
- History heuristic
- Transposition table with 1M entry limit
Test Suite: 80 comprehensive tests covering:
- Move generation
- Special moves (castling, en passant, promotion)
- Check/checkmate/stalemate detection
- PGN import/export
- Algorithm correctness
- API endpoints