Its a physics thing. The direction the boat is pulling the skier is always along the rope, from the skier directly to the boat. With a longer rope, when the skier is at the ball the boat is much further down course and is pulling the skier more down the course. As you ski, you are always moving down course, so this pull is in the same direction you are traveling, or at least partly in the same direction. You can easily ski much wider than the balls. With a short line length (say 39' off), when the skier is at the ball the boat is almost directly perpendicular to the skier and the course direction. So, the boat is pulling the skier directly back towards the middle of the course. This is 180 degrees from the direction you need to be going as you ski wide around the balls and 90 degrees off the down course direction. This makes it much much much more difficult to ski wide enough to get around the balls. In addition to this, with a long rope you can ski 10' wider than the balls and still hold onto the rope with 2 hands. With a very short rope, even with the skier directly perpendicular to the boat, the handle won't reach the ball. You have to release from the boat and make up that distance with your body lean. Hope this helps.