♔ Chess Engine

A Python-based chess engine that uses the Minimax algorithm with Alpha-Beta pruning to calculate the best moves. The engine evaluates board positions based on piece values, positional advantages, and checkmate scenarios. This project includes move generation, check/checkmate detection, and an evaluation function.

🚀 Features

• ✅ Minimax algorithm with Alpha-Beta pruning for efficient search.
• ✅ Move generation for all piece types.
• ✅ Check and checkmate detection.
• ✅ Positional evaluation considering material and control of center squares.
• ✅ Pathfinding to ensure legal moves.
• ✅ Basic AI that can play as White or Black.

🧠 How It Works

1. Position Class

• Manages the current state of the board.
• Tracks pieces and their locations.
• Provides helper functions to retrieve piece positions and check for occupied squares.

2. Move Class

• Represents a move from one square to another.
• Stores the piece involved and the start/end locations.

3. ChessAI Class

• Uses the Minimax algorithm with Alpha-Beta pruning.
• Evaluates the board based on:
• Material value of pieces.
• Positioning advantage (central squares).
• Check and checkmate scenarios.
• Generates legal moves for all piece types.
• Ensures the king is not left in check after a move.

How to Use

git clone https://github.com/your-username/ChessEngine.git
cd chess_engine

python chess_engine.py

Example Usage

pos = Position()

# White pieces
pos.add_piece(1, 'K', 'white', 'e1')
pos.add_piece(2, 'Q', 'white', 'f6')

# Black pieces
pos.add_piece(3, 'K', 'black', 'h8')
pos.add_piece(4, 'p', 'black', 'g7')
pos.add_piece(5, 'p', 'black', 'h7')

ai = ChessAI()

# Find the best move for White
best_move = ai.find_best_move(pos, 'white')
if best_move:
    piece_type = pos.pieces[best_move.piece_id][0]
    print(f"Best move: {piece_type} {best_move.from_square} to {best_move.to_square}")

Output:

Best move: Q f6 to h6

🎯 Evaluation Function

The engine evaluates the position based on:

• Material advantage.
• Control of the center.
• Mobility (number of legal moves).
• Checkmate and stalemate detection.

🏆 Minimax Algorithm with Alpha-Beta Pruning

• The engine searches up to a depth of 3.
• Alpha-Beta pruning reduces the number of nodes evaluated.
• The engine calculates the best move based on the highest evaluation score for White and lowest for Black.

✅ To-Do

• Add castling support.
• Implement en passant.
• Improve evaluation for pawn structure and king safety.
• Add GUI for gameplay.