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.
1. Nf3 c5 2. c4 g6 3. d4 Bg7 4. e4 Qa5
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♞ You have reached Modern Defense: Semi-Averbakh Variation, Pterodactyl Variation A04 — the catalogued line ends exactly here.
Book continuations win% from 1.5M rated games
Matching openings 2
- Pterodactyl Defense A42 2 plies deeper
…and 1 more lines run through this position — keep making moves to narrow it down.
3810 catalogued lines in total · openings encyclopedia