Hard Lines
Learn openings wide before deep.
Import any PGN. Drill with spaced repetition. Cover the early tree first, then go deeper when you’re ready.
The method
Breadth-first is the point.
Depth-first trainers bury you in one long variation while the rest of your repertoire stays untested. Hard Lines expands early choices across your PGN first, so you’re prepared for the moves you actually face.
Spaced repetition schedules what you’ve learned so coverage sticks — not just the line you studied last night.
Bring your own repertoire.
Lichess studies, self-made PGNs, exports from your tools — if it’s a PGN, it’s your course. No marketplace lock-in. Just the lines you chose to play.