Copyright (c) 2001 Wei-Hwa HuangThe game is played on a 11x19 half Go board, with the following initial setup:
If a player drops at cell  the ball moves to  reaching the goal line. The opponent must protect himself, by pushing the ball away from his first line, but he has a desperate position. For e.g., if he plays  then a drop at  wins the game.
Wei-Hwa Huang also proposes some variants:
1. (Original PP) Players may pass at any time. If both players pass, it is a draw.
2. A pressor may be placed anywhere on the board, and not just adjacent to the ball. In those cases, there is no bumping.
3. Seed the board with a random arrangement of pressors.