Explanation

In most of the English chess literature, this checkmate pattern is called "suffocation mate". I don't like this name at all, and the name is very similar to "smothered mate". Therefore I have taken the liberty and used the translation of the German name "Libellenmatt", which is a much more beautiful name. It also describes the pattern visually, and therefore should be much easier to remember. The diagonal of the bishop is the long body of the dragonfly. The knight, the king, and the escape squares guarded by the knight are the wings of the dragonfly.

Examples

White can deliver dragonfly mate with Nh6#. The bishop on c3 controls the escape squares g7 and h8 on the long diagonal.

Sometimes other pieces can help:

Black can deliver dragonfly mate with Nb3#. The bishop on a2 guards the escape square b1. The queen on c7 pins the pawn on c2 and prevents it from capturing the knight with cxb3.

Dragonfly mate can sometimes happen in the opening with the king in the middle, as in the following example after only six moves:

White can win with the dragonfly mate Nxc7#. The bishop on g5 guards the escape squares d8 and e7.

Pattern matching

A bishop controlling escape squares of the king can be very dangerous, especially if the other escape squares are also blocked or guarded.