This kind of checkmate doesn't happen very frequently, It involves checkmating the enemy king in an unfortunate position where his own pieces are blocking all the necessary escape squares. In the example of the diagram below, Black plays Qf3 which turns out to be a horrible blunder. The black King is now right in the middle of his queen & pawn, and there is an enemy king opposite. White uses this opportunity to play Qh2#, and now the black king is trapped inside.leading to his doom. he checkmate is an upside down version of the Dovetail mate. It was named after a study Carlo Cozio that was published in 1766.