Guessing is not calculation. Write your full analysis on a board that never moves, commit it, and Stockfish shows you exactly where your calculation breaks.
You analyse in your head. The board never moves.
Your whole line, committed before any feedback.
Every error refuted. Every find credited.
A guessed move that fails teaches nothing. A committed analysis exposes every gap — and refutes it on the board in front of you.
the grading doctrine →Every position carries an expected score from your rating. The training diary tracks where your calculation breaks — missed candidates, short lines, wrong assessments — and you watch the weakness move.
A position enters the bank only when one move genuinely matters — proved by deep engine verification — and a neural model of human play says instinct alone will not find it. Many keys are quiet moves, and the point often appears only moves later: you have to see the line, defences included.
A new position drops at 06:00 Berlin — midnight New York, the same one for every solver. The week runs Wednesday to Tuesday and it is not a flat ramp: findable when the review email lands, building to Brutal Saturday when you have time to sit with it, easing back as the working week starts. Put the week on your calendar — each day named by its difficulty, never its position.
You do not need one to solve today — it keeps your solves, opens the rest of the week, and brings Wednesday’s follow-up. One email address, no password. Already solving? sign in instead →