Dovetail Mate
In a Dovetail Mate, a queen gives check from a diagonally adjacent square. The queen covers most escapes, while two of the king's own pieces occupy the squares the queen does not control.
What to look for
Look for a queen that can safely move next to the king on a diagonal, with the king's own pieces completing the cage.
Recognize the mechanism
Place the queen diagonally next to the king in your calculation, then mark every square the queen covers. The two remaining escape squares are occupied by the king’s own pieces. Also verify that the queen is safe from capture.
Common practical mistake
An adjacent queen check alone does not establish Dovetail. Orthogonal adjacency is different, and an open escape square or unprotected queen can invalidate the apparent mate.
Training goal
Recognize when the defender's own pieces become a cage around the king.