Dovetail Mate
The queen delivers checkmate while the king's own pieces block its escape on both sides, forming a dovetail shape.
Published 2026-02-01 | Last verified 2026-02-12
Professor Archer says: The dovetail mate is sometimes called Cozio's mate, after Carlo Cozio, the 18th-century Italian chess theorist. I love teaching this pattern because it shows how the queen, the most powerful piece on the board, can deliver checkmate almost single-handedly when the enemy king's own army gets in the way. It is a masterclass in exploiting your opponent's congestion.
What Is the Dovetail Mate?
The dovetail mate, also known as Cozio's mate, is a checkmate pattern in which the queen delivers checkmate to a king whose two diagonal escape squares are blocked by its own pieces. The shape formed by the king and the two blocking pieces resembles the tail of a dove or a swallow — hence the name.
Imagine the king sitting at the tip of a wedge. On either side, diagonally behind it, are its own pieces. These pieces, which should be helping the king, are instead acting as walls. The queen arrives on the opposite side and delivers check, and the king has nowhere to go because its own army is in the way.
This is one of the cleaner and more aesthetically pleasing checkmate patterns because of its symmetry. The two blocking pieces create a balanced shape, and the queen exploits it with precision. It is a pattern that rewards players who pay attention to their opponent's piece placement and look for moments when the enemy king is hemmed in.
The dovetail mate appears in both middlegame and endgame positions. It is particularly common in queen endgames, where the queen's mobility allows it to maneuver to the perfect mating square while the defending king is stuck in a self-made prison.
The Dovetail Mate in Action
In this diagram, we see a pure dovetail mate. The queen on d3 delivers checkmate to the black king on b2. Let us trace through all the king's options to confirm that this is indeed mate.
The king on b2 cannot move to a1 because the queen on d3 controls that diagonal. It cannot move to a2 because the queen covers that square as well. It cannot move to a3 because the queen controls it. It cannot move to b3 because the queen directly attacks that square. It cannot move to c1 because the queen covers it too. And crucially, it cannot move to b1 or c2 because those squares are occupied by its own pieces — the rook on b1 and the pawn on c2.
This is the dovetail: the pieces on b1 and c2 form the two prongs of the V-shape behind the king, and the queen covers everything else. The geometry is elegant and the result is final.
Dovetail mate: the king on b2 is checkmated by the queen on d3. Its own rook on b1 and pawn on c2 block the diagonal escapes.
Spotting Dovetail Mate Opportunities
To recognize dovetail mate possibilities in your games, look for situations where the enemy king is cramped and has pieces on both diagonal squares behind it. This typically happens when the opponent's position is congested — too many pieces clustered together without coordination.
The queen is the star of this checkmate because it can control so many squares simultaneously. From a single position, the queen can cover the king's forward squares, the side squares, and everything in between, leaving only the diagonal retreat squares. If those diagonals are blocked by friendly pieces, the mate is complete.
Positions where the king has been pushed to the edge of the board are prime territory for the dovetail mate. A king on a2, b2, b1, or similar edge squares often finds itself with limited mobility, and its remaining pieces tend to cluster nearby, creating the blocking conditions needed.
In queen endgames, the dovetail mate is particularly relevant. With fewer pieces on the board, the queen has more manoeuvrability, and the defending king has fewer resources to create escape routes. I tell my students to always check whether the enemy king's diagonal squares are blocked before looking for a queen check — if both diagonals are sealed, the dovetail mate may be just one move away.
Dovetail Mate FAQ
What is the difference between the dovetail mate and the epaulette mate?
In the dovetail mate, the king's diagonal escape squares are blocked by its own pieces. In the epaulette mate, the king's side escape squares (on the same rank) are blocked by its own pieces. Both involve the king being trapped by friendly pieces, but the geometry of the blocking is different.
Is the dovetail mate only delivered by the queen?
In the classical pattern, yes. The queen is the only piece mobile enough to cover all the remaining escape squares while the diagonals are blocked by the king's own pieces. Theoretically, other pieces with support could create similar positions, but the queen is the standard instrument.
Why is it also called Cozio's mate?
The pattern is named after Carlo Cozio (1715-1780), an Italian chess master and author who analyzed many mating patterns in his extensive chess writings. Cozio was one of the strongest players of the 18th century and contributed significantly to chess theory.
Professor Archer says: The dovetail shape is distinctive once you train your eye to spot it. The king sits at the point of a V, with its own pieces on the two diagonal squares behind it. The queen lands on the opposite point of the V, and the mate is complete. I encourage my students to look for this V-shape whenever the enemy king is cramped and surrounded by its own pieces.
Quick Quiz
In the dovetail mate, what blocks the king's escape?
- Its own pieces on both diagonal squares behind the king (Correct) - Correct. The dovetail mate is defined by the king's own pieces blocking both diagonal retreat squares, forming the characteristic V or swallow-tail shape.
- Enemy pawns surrounding the king - The dovetail mate is not about enemy pawns. The key feature is that the king's own pieces block the diagonal escape squares, which is what gives the pattern its distinctive shape.
- The edge of the board on all sides - While the king is often near the edge, it is not the board edge that blocks the diagonal escape squares. It is the king's own pieces that create the dovetail shape.
- A knight controlling all nearby squares - The dovetail mate does not involve a knight. The queen delivers the check, and the king's own pieces on the diagonal squares complete the trap.