🎯 Overview

This tool helps you build a chess opening repertoire by analyzing a database of games and using an engine (Stockfish) to suggest the best moves for your chosen side.

📁 Step 1: Load Database

• Load a PGN file - Upload a file with multiple games (e.g., from Mega Database, your own games, or downloaded from the web)
• OR Load a JSON database - If you've previously saved a processed database, you can load it directly

🎨 Step 2: Apply Filters (Optional but Recommended)

• Player Name - Enter a specific player's name (e.g., "Kamsky") to only use their games
• Player's Color - Choose if you want games where this player played White or Black
• Result - Filter by game outcome (wins, losses, draws)
• Enable Filter - Check this to apply the filters

Example: To build a repertoire for Kamsky as White, set Player="Kamsky", Color="White", Result="Any"

🔨 Step 3: Build Database

Click "Build Database" - this creates a statistical database from the PGN file. The result is a JSON-like structure in memory containing:

• All unique positions (by FEN)
• For each position, all moves played and how many times
• Move percentages based on frequency

💾 Save Database - You can save this database as a JSON file for later use (saves processing time next time)

⚙️ Step 4: Configure Repertoire Settings

• Training Side - Choose which color YOU will play (White or Black)
• Min. Reach Probability - Stop expanding lines that fall below this percentage (e.g., 1% means stop if a line has less than 1% chance of occurring)
• Top N Gegner-Züge - Number of opponent moves to consider at each position (e.g., top 3 most frequent moves)
• Min. Gegner-Zug % - Only consider opponent moves that appear at least this percentage of the time
• Engine Depth - How deep Stockfish analyzes (higher = stronger but slower)
• Max. Plies - Maximum depth of the repertoire tree (1 ply = half move)
• Starting Position - Choose where to start:
  • Initial position - Start from move 1
  • After move sequence - Enter moves like "e4 e5 d4 exd4"
  • From FEN - Paste a specific FEN position

🚀 Step 5: Generate Repertoire

Click "Generate Repertoire Tree" - this builds the actual repertoire:

• 🟩 Green moves = Your moves (chosen by the engine)
• 🟨 Yellow moves = Opponent moves (from the database statistics)
• 🔴 Red gaps = Coverage gaps (opponent moves not covered by your repertoire)
• Percentages show how likely each position is to occur

📊 Understanding the Output

• Tree View - Visual representation of the repertoire tree
• PGN Export - Complete repertoire as PGN with lines and probabilities
• Stats - Shows nodes, complete lines, coverage percentage, and gaps

🔍 What do the parameters mean?

• Top N Gegner-Züge - At each opponent position, only include the N most frequent moves from your database. Example: If opponents play 10 different moves but you set N=3, you'll only prepare against the top 3.
• Min. Gegner-Zug % - Filter out rare moves. Example: Set to 5% to ignore moves played less than 5% of the time.
• Min. Reach Probability - Stops building lines that become too rare. Example: 1% means if a line has less than 1% chance of occurring, stop expanding it.

💡 Tips

• Start with a small database (e.g., 100 games) to test settings
• Save your database as JSON to avoid reprocessing large PGN files
• For a complete repertoire, use multiple databases (e.g., games from different players)
• Export PGN to study and learn and train the repertoire in the opening-repertoire-trainer or in your favorite chess software