Stop solving random chess puzzles.
Solve puzzles from your own games.
Blunder Book imports your Lichess games, finds mistakes, and turns them into puzzles. Target your training on tactics you actually miss.
Start for free · No password needed · Read-only access
Find the moves you should have played, and compare solutions to your in-game mistakes. Explore positions further with the Stockfish engine.
Your Games, Your Puzzles
Every puzzle comes from your games. No contrived or generic positions you'll never see in-game.
Game Insights
See the types of tactics you tend to miss in games, which cost you the most evaluation, and more.
Targeted Training
Focus your puzzle training on tactical themes that you miss in your games. Train smarter, improve faster.
Spaced Repetition
Puzzles you struggle with come back more often. Ones you've mastered fade away. Your training adapts to you.
See which kinds of tactics you miss in-game, what time of day you blunder most, and more in the dashboard.
Connect your Lichess account
One-click secure OAuth login with Lichess. We only read your publicly available, cloud-analyzed games.
Import & analyze your games
Blunder Book detects tactically charged moments with engine analysis, and generates chess puzzles.
Drill your weaknesses
Solve puzzles built from your own mistakes, and compare your solutions to what you actually played.
Your personalized puzzles are waiting.
Start writing your Blunder Book.
Start for free · No password needed · Read-only access