: These are designed for offline training or for use in external chess software (like Scid vs. PC) where users want to drill tactics that arise from their own opening repertoire. Where to Find the Data
These zip files are typically PGN (Portable Game Notation) collections structured so you can practice tactics specifically related to certain openings: Lichess Puzzles By Eco zip
: Each puzzle entry includes the starting FEN, the move sequence to solve it, the puzzle's rating, and "Themes" tags (e.g., fork, pin, mate in 2). : These are designed for offline training or
While the official Lichess database provides puzzles in a single large CSV or BZ2 file, the "By ECO" organization was a specific project shared by community members: download all puzzles - Lichess.org the move sequence to solve it