Ball markers are pretty standard at snooker and all the refs carry them. The marker fits snugly under the ball and then you can pick the ball up, clean it and replace it accurately. You only need to get it under one side of the ball, so that if the ball was up against the MR on one side it would not be a problem.Does anyone know if they make some sort of device to mark a ball so the Magic Rack can be moved? Perhaps a small cradle that goes partially around the ball?
When two balls are touching or nearly touching, it's a much more complicated problem.