One set of puzzles per day for 1000 days. Puzzles are grouped by tactical technique: a day introducing a new pattern is followed by a day mixing it back in with the last few you learned, so patterns stay recognizable once the lesson is over rather than fading after a single solve. Each full pass through the technique list climbs to a harder rating band. The final 270 days serve one puzzle a day rated 2600 and up — as hard as this collection gets. Skipped days are never lost; your next unsolved set always waits, and the calendar turns green on each day you finish a set — click any green day to replay it. Puzzles are drawn from the Lichess puzzle database (CC0), curated for quality, with trivial one-movers excluded. Your progress follows the name you joined the Chess Coach leaderboard with, or stays in this browser if you have not joined.