You must turn over NINE black pieces, so that they show white, leaving just one black piece at the end.
For each turn, click FOUR pieces as you count 1-2-3-4 around the circle.
Your count may include either black or white pieces at positions 2 and 3 but you must start and end each count on a BLACK piece. The black piece at count 4 will then be turned over, showing white.
You cannot jump over pieces.
Each turn can start on ANY remaining black piece, and each count may go either clockwise or anti-clockwise.
If you click a piece from which you cannot end your count, YOU LOSE!