My idea of the bump and run is when you can’t land it on the green and stop it by the hole because there is not enough green to work with or it is too much downhill so that the ball is rolling too fast. So you land short of the green and let it bounce and then roll onto the green and to the hole. Imagine you were going to toss a ball to the green where would you land it so it slows down enough to stop by the hole, use this idea and chose a club that is going to give you the height you visualized tossing it.