About the project

Debutario is a website where you build your own opening repertoire and work out why every move belongs in it. The Repertoire section suggests continuations from the statistics of games played at your level, shows where your repertoire still has gaps, and helps you retain the lines with spaced-repetition practice. The repertoire within the free saved-move limit and practice work without an account. Sync across devices is also free, but requires an account.

Move frequencies and results in the Repertoire section come from a corpus of real games — separately for players of different levels and for masters. Positions missing from the corpus are evaluated by the Stockfish chess engine right in your browser.