Import completed games, find recurring decisions, and practise the positions that matter to you.
Stockfish scans your moves and spends extra time checking possible mistakes. Evaluations are estimates, not human win probabilities. Short searches can miss ideas.
“Practical candidate” is a transparent heuristic: among up to three engine candidates within 0.60 pawns of the leading move, we favour observable features such as development, castling and forcing moves. It is not a trained human model, and it does not yet judge entire pawn structures or long-term plans.
Exercises ask for one verified move, then show a continuation. They may accept several candidates. An unlisted move is not automatically a bad move. Theme labels describe the position; repeated examples suggest a habit, not a diagnosis.
Your main skill number now shows change from a baseline of at least 3 relevant games and 8 decisions. It is not mastery out of 100. The underlying decision-quality average can be high at any rating because easy moves count too; it remains visible in the measurement details. We use up to 20 recent Chess.com games per theme. It is not Elo, a percentile or a validated ability measure. Fewer than 3 games or 8 relevant decisions is marked provisional. Short engine searches and automatic theme labels are imperfect.
A first unassisted solve of a due position earns 2 potential points, capped at 20 pending per theme. Repeating it earns no further credit. Potential is a practice target, not a prediction. Only better results in Chess.com games played after that practice can consolidate it. Importing older games, PGNs, or sample games cannot confirm that improvement. Demonstrated scores can go down.
No Chess.com password is needed. Completed public games and practice results are stored on this server. A necessary browser cookie keeps your workspace separate. There are no analytics or advertising trackers. Clearing the cookie loses access to this workspace; export your PGNs first. Account sync is not available yet.
Chess.com archives may take up to 12 hours to update. Imports run in batches to share computing resources; you can continue importing older games. There is no paid tier or daily game allowance.
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