We used to lift the front of a Sky a jump and set it on our steel toe boots. Then with playfield almost flat, the ball would stick in a roll over and you would just jiggle it an the points racked up. We would get so many free games that we started unplugging the machine and putting an out of order sign on it so people wouldn't use all our fee games while we were gone. I'm not sure anyone ever really figured out what we were doing. Good times!