Create and refine a chess opening repertoire quickly. Import courses, PGN files, or Lichess Studies; train either side, practise with Opening Sparring, review online games, and prepare for opponents.
Build
Import a repertoire PGN, build one yourself, or generate an editable snapshot of any online player's recurring opening habits. Change or add lines using master and online games, evaluation data, or Opening Lab suggestions.
Analyze
Run a customizable repertoire review to uncover dangerous opponent ideas, or prepare for an online player by finding repeated opening weaknesses in their games. Review actionable findings on a board and export reports or move trees as PDF.
Review
Cross-check your opening moves played in online games to see whether you remember your lines and use deviations to improve. Get a detailed report on mistakes or directly train the relevant positions.
Train
Train your complete repertoire or selected parts with spaced repetition, or choose any opening or line in your repertoire and train everything from that position.
Practice
Practise real opening decisions from either side against frequency-weighted moves from online or master game databases. Every legal move is evaluated so you can see where your choices gain or lose ground.
Switch Sides
Switch sides to ensure you have a strong command over what opponent moves are covered in your repertoire for a given position so you don't start guessing over the board.