Hard Lines

What it does

Depth-first opening trainers bury you in one long line. Hard Lines imports any PGN (Lichess studies, your own files, course exports) and drills your early choices across the whole tree first, then goes deeper as you're ready, using spaced repetition to keep it all fresh. Bring your own repertoire, no marketplace lock-in.

Import any PGN and learn chess openings breadth-first, with spaced repetition. Wide coverage before deep lines.

Import any PGN. Drill with spaced repetition. Cover the early tree first, then go deeper when you’re ready. 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. 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 tofrom hardlines.app

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