Checks, captures and threats: the scan before every move

Look for checkmate first — yours and theirs. Before anything else, check every check. Then check theirs.

When the opponent leaves material undefended, take it. Start every move by looking at what your opponent’s last move stopped defending.

When something of yours is attacked and undefended, deal with it. After their move, ask what it attacks before you ask what you want to do.

The board defines the opportunity — a position where the principle applies — and Stockfish is the referee: a miss is counted only when the engine’s own line at that move embodies the principle, so the row never blames you for a rule the position did not ask for. The row reads as tests passed out of tests taken.