Reversi problem #505

The task

To move

Dark

Difficulty

Easy

Goal

corner in 2

The middle game: no corner can be taken directly, but one move prepares it. Two turns to a corner: the first move must leave the opponent only replies that open one.

What to look for

• The target is a corner.
• The key move threatens nothing at first sight; its point comes later.

How the answer is checked

There is exactly one first move that forces the result; any other first move allows the defence to escape. Moves that keep the forced result are accepted later in the line, and a move that loses it is taken back with a short note.