Queen mates with a defender forming a triangle with the king
A queen delivers mate from a square diagonally next to the king, defended by another piece so the king cannot capture. The queen, defender, and king form a triangle. The king's other escape squares are covered by the queen itself or its supporters. Often built around a knight or rook defending the queen one knight-move away.
Queen attacks diagonally adjacent to the king.
2 more clean runs (at any point) to reach Recall.
Black to move. White king has slipped to h3 thinking it has shelter behind the pawns. Black has a queen on e4 and a rook on g2.
Queen attacks diagonally adjacent to the king.
2 more clean runs (at any point) to reach Recall.