Swindles: Taking Both Squares of a Pair

In Othello there are many places where two squares form a pair. In a region with only two empty squares left, if you enter one square, the opponent's best reply is usually the remaining one. But if the opponent cannot play the remaining square, the side that entered first takes both squares; this is called a swindle. It is a swindle only when the opponent cannot enter because there is no legal move there, not when they avoid it on purpose.

The most common pair is a corner and the C-square next to it, and there are two orders for entering it.

• Corner first (basic): after you take the corner, the opponent cannot enter the C-square.
• C-square first: when corner first does not work, play the C-square first so that the opponent cannot enter the corner. The C-square move must be a quiet move that does not flip the opponent's disc on the X-square, and afterwards you must be able to take the corner as well. If the C-square move flips the X-square, it is not a swindle.
• How to check: for the opponent to play the remaining square, there must be an opponent disc at the end of a line extending from it. If there is no such line after your move, the opponent has to pass or play elsewhere, and you gain a tempo.