A swallow's tail mate, also called the swallow tail mate or the Guéridon mate, is a checkmate by a protected queen standing directly next to the king in a straight line. The king's own pieces sit on the two squares diagonally behind it, forming a V shape like a swallow's tail. Every puzzle on this page ends in a swallow's tail mate, comes from a real game and is close to your puzzle rating.
A queen right in front of the king covers a lot. Along its rank it takes the two squares beside itself. Along its diagonals it takes the two squares beside the king. It also covers the square behind the king, because the king cannot retreat along the line of the check. That leaves exactly two squares: the ones diagonally behind the king. If the king's own pieces stand there, and the queen is protected, the king is mated.
Here is a position with an opening feel. White has a king on e1, a queen on h3, a knight on g5, rooks on a1 and h1, a knight on b1, a bishop on c1 and pawns on a2, b2, c2, d2, f2, g2 and h2. Black has a king on e7, a queen on d8, a bishop on f8, rooks on a8 and h8, and pawns on a7, b7, c7, g7 and h7. White plays 1.Qe6#. The queen covers d6, f6, d7, f7 and e8. The knight on g5 defends the queen. The two squares left, d8 and f8, hold Black's own queen and bishop: the tail.
Compared with most mating patterns, the swallow's tail turns up in the opening fairly often. The reason is in the example: when the king is drawn out to e7 or e6 early, often after a sacrifice on f7, the queen and bishop can still be on their starting squares on either side of where it came from. Those two undeveloped pieces are the tail.
It happens in endgames too, wherever a king has two of its own pieces diagonally behind it. The pattern is the same; only the pieces change.
These two are often confused. In a swallow's tail mate the queen checks from a straight neighbour, in front of or beside the king, and the blocked squares are the two diagonal squares on the far side. In a dovetail mate the queen checks from a diagonal neighbour, and the blocked squares are the two straight squares on the far side. Where the queen stands tells you which one you are looking at.
When an enemy king has left its back rank and still has pieces diagonally behind it, look at the square directly in front of it. Can your queen get there with support? A knight or pawn defending that square is the most common helper.
For the defender, the answer is not to walk the king in front of its own undeveloped pieces. If the king must move up the board early, get the queen or bishop off the squares behind it so that the king keeps a retreat.
The attacker's mistake is putting the queen in front of the king without a defender, where the king captures it. The defender's mistake is thinking that pieces standing next to the king protect it. Here they take away its last two squares.
Most puzzles on this page are short, so focus on recognising the shape at a glance. If you are stuck, the hint first shows the piece to move, then the move. Once solved, the full line appears beside the board. Train it next to dovetail mates and epaulette mates, the other patterns where the king's own pieces do the attacker's work, and see the checkmate patterns page for the rest.
For mixed tactics at your level, use Puzzle Training. For speed, try Puzzle Storm, and to repeat a fixed set until it is automatic, the Woodpecker Method. Elo Maxing rates you on every tactical motif and serves the weakest next, and Pattern Drill builds practice from the patterns your own games show you miss. For a daily habit, read about the daily chess puzzle.
A checkmate by a protected queen directly in front of or beside the king, with the king's own pieces on the two squares diagonally behind it.
Yes. Swallow's tail mate, swallow tail mate and Guéridon mate are names for the same pattern.
In a swallow's tail mate the queen checks in a straight line from the next square. In a dovetail mate it checks from a diagonal square.
Because a king pulled out to e7 or e6 early can still have its queen and bishop on their starting squares behind it, and those two pieces block its escape.