I’m a fan of puzzles and riddles. Last week I came across one involving chess so I wanted to share with the Decorah Sjakklubb.
In the puzzle below, black’s king is invisible and on the board somewhere in a legal square (which would be somewhere in the 6×6 square defined by the c3 to h8 diagonal). It is white’s move.
Black has to follow the rules of chess and cannot move into check. Since black is invisible, however, white is allowed to move into check (that is, the white king can move right next to the black king since white cannot see it, at which point the black king can capture the white king and win the game). Since black has only the invisible king to work with, black will move into a stalemate situation if one becomes available.
It is white’s move. What series of moves will guarantee a victory without losing a piece?

There are many solutions to this. It is a great exercise in using your pieces together to deliver a checkmate. For one such solution, and the source of riddle itself, visit FiveThirtyEight’s The Riddler, and scroll down to the solutions for last week’s Riddler.