Opening explorer

Walk any move order through the catalog: pick a book continuation and watch the board, or open the matching ECO lines on the side. By default move orders are strict — flip the toggle to group by position and pull in transpositions.

⚖ Grouping by position Grouping by position: lines that reach this position by a different move order are included too.

1. d4 g6 2. Nf3 Bg7 3. e4 c5 4. dxc5 Qa5 ◀ Undo move

♞ You have reached Pterodactyl Defense: Western, Rhamphorhynchus B27 — the catalogued line ends exactly here.

Book continuations win% from 1.5M rated games

Nc3 3

Matching openings 4

Pterodactyl Defense: Sicilian, Rhamphorhynchus B27 1 ply deeper
Pterodactyl Defense: Sicilian, Pteranodon B27 3 plies deeper
Sicilian Defense: Hyperaccelerated Pterodactyl, Exchange Variation B27 4 plies deeper

…and 1 more lines run through this position — keep making moves to narrow it down.

3810 catalogued lines in total · openings encyclopedia