Blunder Trainer

Practice mistakes from your own Lichess games. Sign-in is required; during beta, availability is shown in the main navigation.

Prepare your cards

From any player's Explore profile, open Analyzed mistakes to see Lichess-labeled Inaccuracies, Mistakes and Blunders across imported games. Scan recent analyses requests the newest 1,000 analyzed games from Lichess; Scan older analyses continues from the oldest imported analysis. The list is paginated and can be filtered by Lichess judgment. Public Lichess analysis is read through the game API, not scraped from HTML, and no engine runs on this server.

After signing in, Extract Blunders builds practice cards only from moves that Lichess itself labeled Blunder. Reimport games analyzed since an earlier import before extracting, because old cached evaluations may lack their original judgment and suggested move.

Positions without a known legal solution are counted separately and do not enter the review queue. Cloud evaluation is not available for every position; extraction can be repeated later to fill missing solutions without resetting existing learning progress.

Train

1. Start a review session. 2. Play your proposed move on the board, or choose Show Solution. 3. For a promotion, choose Queen, Rook, Bishop or Knight. 4. Compare your move with the known solution. 5. If you found the move on the first try, choose Good or Easy. If you missed it or revealed the solution, choose Again; the card returns sooner.

The move feedback compares against one known solution, rather than running a new engine search. FSRS determines the next repetition date from the result.

Saved progress

The card's new schedule and its rating history are saved together. A failed save shows an error and leaves the card on screen. A repeated submission of a card that is no longer due is rejected. Signing out does not erase your cards.

Limits

The trainer uses precomputed Lichess analysis and cloud evaluations. It does not create new engine analysis. The personal trainer remains behind the Lichess-login feature flag until a real OAuth round trip is accepted. The public mistakes browser works without login. The existing web app includes a PWA manifest and service worker for installation; account pages and API data still require a network connection.