Play any legal move — including a surprise from your opponent. Stockfish 18 names the best reply. The full official opening and variation name updates from the world ECO book as you go. Back, Next, or pick a line to practice.
3,810 official names from the world ECO book. Pick a line — the board jumps there and names update as you move.
Arrow keys back/next · F flips · click any move in the list to jump there.
Stockfish 18 runs in your browser. If they play something unexpected, make that move on the board — the reply updates immediately.
Published games in this position — every named opening and variation as it appears in the world database. A move with no games is still legal.
No master games at this point. Any legal move is still allowed — Stockfish will score it.
Click any move. That becomes the position. Stockfish then tells you what to play next.
No first-publication year on file for this line. Games below are real scores from the masters database.
No published games at this exact position yet. Make a book move to see who played it and in which year.
