reversing a single stone (Othello)
A technical term in the board game Othello/Reversi, referring to the act of flipping exactly one opponent's stone in a turn.
He gradually gained an advantage by reversing single stones.
Compound of 一石 (isseki, 'one stone') and 返し (gaeshi, 'turning over, reversing'), literally 'one-stone reversal'. The term is specific to Othello/Reversi.