Blunder Zero : Chess Coach

Your games. Your mistakes. Your coach. On-device chess review with Stockfish 18.

Stop losing the same way twice.

BlunderZero is a personal chess coach built around your own games. It helps you review what happened, find the mistakes that keep coming back, and turn those positions into focused training.

Instead of giving you endless random puzzles, BlunderZero studies your actual blunders, missed tactics, weak habits, and opening problems, then helps you practice the patterns that cost you games.

Analysis runs on device with Stockfish, so review is fast, private, and available offline.

WHY BLUNDERZERO?

Most chess tools show what went wrong in one game.

BlunderZero shows what keeps going wrong across your games, then helps you fix it.

Review every move with clear explanations. Find recurring mistakes and weak habits. Train from positions you actually played. Build lasting improvement instead of chasing puzzle ratings.

KEY FEATURES

Personal Game Review Import your games and get a move-by-move breakdown with clear coach feedback.

Train From Your Own Mistakes Convert your blunders, mistakes, and missed tactics into personalized training drills.

Human-Like Insight with Maia See what players at your level would naturally consider, alongside Stockfish’s best move.

Real-Time Chess Coach Get feedback while you play and learn to spot mistakes before they happen.

Blunder Detection Identify the critical moments that changed the game and understand why they mattered.

Recurring Mistake Tracking Discover patterns that appear across your games and focus your training where it matters most.

Opening Repertoire Tracking See your most played openings, where you deviate, and which lines need attention.

Master Games Lookup Compare your positions with stronger players and learn from real game examples.

On-Device Stockfish Analysis Fast, private, offline-first analysis directly on your phone.

Background Analysis Analyze multiple games while continuing to review and train.

ACCURACY YOU CAN VERIFY

We independently validated BlunderZero’s accuracy scoring across 800 player-games. The results showed a Pearson correlation of 0.978 against a widely used chess accuracy reference, with scores within 3 points on 85% of games.

MADE FOR PLAYERS WHO WANT TO IMPROVE

Whether you are a casual player, club player, or competitive online player, BlunderZero helps you:

• Find recurring mistakes • Understand why they happen • Train from your own games • Build stronger habits • Stop repeating the same patterns

HOW IT WORKS

1. Import a game or play inside the app
2. Review every move with coach feedback
3. Train the mistakes that matter most
4. Track your weaknesses as they improve

Stop repeating the same mistakes. Start training on the games you actually play.