Stop solving random puzzles.
Fix your blunders.
Blunder Book imports your Lichess games, finds every mistake you made, and turns them into puzzles you can drill until they stick. Targeted, efficient training based on patterns you actually miss.
Login with Lichess →Free to start · No password needed · Read-only access
Your Games, Your Puzzles
Every puzzle comes from a real mistake in your games. No generic positions — just the tactics you need to learn.
Targeted Training
Why solve random puzzles when you can drill the tactics you actually miss? 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.
Connect your Lichess account
One-click OAuth login. We only read your analyzed games.
Import & analyze your games
We pull your recent games and extract every blunder and missed tactic into interactive puzzles.
Drill your weaknesses
Solve puzzles built from your own mistakes. Spaced repetition resurfaces the ones you struggle with most.
Your blunders are waiting.
Start turning mistakes into improvement.
Get Started For Free →