chess-detect 0.1.1

Automatic detection of chess tactical themes in PGN games

chess_detect

Automatic detection of chess tactical themes in PGN games using python-chess.

Analyzes PGN files and annotates moves with tactical motifs: forks, pins, skewers, discovered checks, and more. Supports Russian and English output with visual PGN arrow annotations.

Документация на русском

Installation

pip install chess-detect

For development:

git clone https://github.com/aslyamov/chess_detect.git
cd chess_detect
pip install -e ".[dev]"

Quick Start

from chess_detect import ChessDetector

detector = ChessDetector(lang="en")  # or lang="ru"

pgn = """
1. e4 e5 2. Nf3 Nc6 3. Bb5 a6
"""

result = detector.analyze(pgn)
print(result)
# PGN with tactical annotations in comments

Supported Tactics

Theme	Russian	English
Double Check	Двойной шах	Double Check
Fork	Вилка	Fork
Discovered Check	Вскрытый шах	Discovered Check
Pin	Связка	Pin
Skewer	Копьё	Skewer
Trapped Piece	Пойманная фигура	Trapped Piece
Hanging Capture	Взятие висящей фигуры	Hanging Capture
Removing Defender (material)	Уничтожение защитника (выигрыш фигуры)	Removing Defender (winning material)
Removing Defender (mate)	Уничтожение защитника (угроза мата)	Removing Defender (mate threat)
Exploiting Pin	Использование связки	Exploiting Pin

Planned

• Deflection
• Decoy
• Zwischenzug
• Discovered Attack
• Back Rank Mate
• Smothered Mate

PGN Arrow Annotations

Detected tactics are visualized with green arrows ([%cal]) and square highlights ([%csl]) in the PGN output. These annotations are displayed by chess viewers like Lichess and chess.com.

Example output:

1. Nc7+ { [%csl Ga8,Ge8][%cal Gc7a8,Gc7e8] Fork (Nc7 → Qa8, Ke8) }

Architecture

chess_detect/
├── __init__.py          # Exports ChessDetector
├── detector.py          # Main class
├── context.py           # MoveContext — lazy evaluation
├── utils.py             # Utilities (piece values, vulnerability checks)
├── i18n/                # Translations
│   ├── ru.py
│   └── en.py
└── detectors/
    ├── base.py          # BaseDetector
    └── tactics/
        ├── double_check.py
        ├── fork.py
        ├── discovered_check.py
        ├── pin.py
        ├── skewer.py
        ├── trapped.py
        ├── hanging_capture.py
        ├── removing_defender.py
        └── exploiting_pin.py

Adding a New Detector

from ..base import BaseDetector
from ...context import MoveContext

class MyTacticDetector(BaseDetector):
    key = "my_tactic"  # i18n key

    def detect(self, ctx: MoveContext) -> bool:
        # ctx.board_before — position before the move
        # ctx.board_after — position after the move
        # ctx.move — the move itself
        # ctx.is_check — is it check?
        # ctx.is_capture — is it a capture?
        # ctx.captured_piece — captured piece
        return False

1. Create a file in detectors/tactics/
2. Add translations to i18n/ru.py and i18n/en.py
3. Register in detector.py

Tests

python -m pytest tests/ -v

89 tests — all passing.

License

MIT