Obsidian Chess Intelligence

A browser-based chess application with a Python alpha-beta engine, PGN game analysis, and a React-powered interface.

Features

• Play against the engine as White or Black.
• Board Analysis mode: move either side freely and inspect the current best move.
• Alpha-beta pruning with capture ordering and quiescence search to reduce tactical oversights.
• Position evaluation with material, pawn advancement, central control, mobility, and bishop-pair scoring.
• Opening-book responses for common opening positions.
• PGN paste/upload and move-by-move analysis.
• PGN labels for Book Move, Best Move, Brilliant, Good Move, Mistake, and Blunder.
• Back/forward PGN replay with board position, move highlights, best-move alternatives, and evaluation bar.
• Flip-board control, Chess.com Neo piece artwork, move sounds, and game-over popups.

Tech stack

• Backend: Python, Flask, python-chess
• Engine: Alpha-beta pruning, quiescence search, static evaluation
• Frontend: React 18 loaded through CDN
• Styling: Custom responsive CSS with a purple gradient design

Run locally

Prerequisites: Python 3.10 or later.

cd C:\Users\HP\OneDrive\Documents\chess
py -m pip install -r requirements.txt
py app.py

Open http://127.0.0.1:5000 in your browser.

How to use

Play mode

1. Select Vs Engine.
2. Select White or Black. When Black is selected, the engine makes the opening White move.
3. Click a piece, then a highlighted destination square.
4. Use Flip to change board orientation.

Board Analysis

1. Select Board Analysis.
2. Move legal pieces for either side.
3. The engine calculates and displays a best continuation plus the evaluation bar.

PGN analysis

1. Open Analyze PGN.
2. Paste a PGN game or upload a .pgn file.
3. Run the analysis.
4. Select a move or use Back/Forward to replay it on the board.
5. For mistakes and blunders, inspect the suggested best continuation.

Project structure

app.py                 Flask API and chess engine
requirements.txt       Python dependencies
templates/index.html   React application shell
static/app.js          React frontend
static/style.css       Interface styling

Notes

The engine is intentionally self-contained and uses alpha-beta search rather than an external chess-engine binary. Chess.com Neo piece images and React are loaded from public CDNs, so an internet connection is needed for those visual/frontend assets.