Chess notation cheat-sheet (for new readers)
Pieces: K king · Q queen · R rook · B bishop · N knight · (a pawn move has no letter)
Actions: x takes · + check · # mate · O-O short castles · O-O-O long castles · e8=Q pawn promotes to queen
Annotations: ! good move · !! brilliant · ? mistake · ?? blunder
Reading the dovetail mate chess puzzles board
Start from the king and read outward. In a dovetail finish the king is off the edge, somewhere with breathing room, yet it has none. Your queen stands on a square diagonally next to it, and what truly seals the mate is that every square around the king is either covered by the queen or plugged by the king's own men.
Now check the eight neighbor squares. The queen, from her diagonal corner, covers the king's diagonal neighbors and a couple of squares along her lines. The two squares left open, the orthogonal exits to the side and front of the king, are blocked by the king's own pieces, a pawn, a rook, whatever got stuck there. The rest sit on the queen's lines. Eight squares, none free. When I scroll back through a solved position, that pair of friendly blockers on the orthogonal exits is the first thing to confirm it really was a dovetail and not a near miss.
Spotting the trigger in dovetail mate chess puzzles
The pattern rarely announces itself. What tips you off is a slightly boxed-in king with two of its own units crowding the orthogonal squares to its side and front. Those crowders are doing the defender's work for you. Your job is to find a check that lands on a diagonal-adjacent square and leaves the king no exit.
So the search has two halves. First, can you deliver the check so that every neighbor square is sealed? If the king can step out or capture the checking piece, no mate. Second, are both orthogonal escape squares already occupied by enemy men? If one is empty, the king slips. In real games the setup often arrives after a sacrifice peels open the king or a pawn push freezes its own escape. The puzzles here pull computer-verified positions tagged for this exact pattern from real games, so every solution is a clean, real dovetail rather than a contrived diagram.
Dovetail, swallowtail, and epaulette on the trainer
Three V-shaped finishes get confused constantly, and sorting them keeps your tactics honest. The split comes down to where the queen stands and which squares the king's own pieces block.
Dovetail (also called Cozio's mate, after Carlo Cozio's 1766 treatise): the queen checks from a square diagonally next to the king, and because she already covers the king's diagonal neighbors, the two blocked escape squares are the orthogonal ones to its side and front. Picture a king on g3 with the queen on h2 and the king's own men stuck on f3 and g4, both straight neighbors. Epaulette: the blocked squares are the lateral ones, on the same rank beside the king, like a pair of shoulder boards. Swallowtail, sometimes called gueridon: the queen checks from directly in front, orthogonally adjacent, while the two diagonal squares behind the king are the ones his own pieces seal. Same V, different walls. One caution: the pattern holds only if neither of the king's two blocking pieces is an unpinned knight, since an unpinned knight could interpose or cover the checking square and spoil the mate. Run a batch of each across the rating slider and the distinction stops being a definition and becomes a reflex.