Almost every successful animator, CG or not, will tell you that it is imperative that you draw every day. They will say that the better you draw, the better you can animate. But why? Is it just because Milt Kahl and Glen Keane were both superb draftsmen as well as animators, so therefore it must be true. You might say that animation is mostly acting and physics and either the computer or the clean up artist will make it look pretty for you which is not untrue. In the Illusion of Life, Frank Thomas states that Milt Kahl was the best animator because his draftsmanship allowed him to execute subtleties in the animation better than anyone else. I think that this is very true but I also think that there is more to it. When we animate, the performance first starts off in our brain. Then, through much trial and error, we put it into some form that will communicate to an audience. We are communicating to an audience visually. So lets think about this in the form of speaking. When we are young we have trouble communicating what we are thinking and people have trouble understanding what we are saying. Also when we are younger our thoughts might not even be clear to us. But as we practice, we become better at knowing what we are trying to say and being able to say it. You might say that animation is an art form and not just a way to communicate. But think about this. Singing is a audible art form and you must learn to speak before you can sing. Over the centuries the greatest visual artists start out drawing. They all will continue to draw and sketch through out their whole life. Why? Because it is the best way to learn and continue improving on how well we can communicate visually. Drawing also helps how we think visually. Just as speaking builds up a mental library of ways to communicate audibly, drawing builds up a mental library of ways to communicate visually. It will also help us clarify our initial ideas so that we can perceive problems that we will run into, without all the work. Also as animators we need to be drawing people and what they are thinking. This will do two things for us. One, it will help us communicate visually, and two, it will build up a library of sincere and real acting. It will help us with both the communication and the craft. Milt Kahl was the best because he could communicate visually with the most clarity. He could get what was in his head, into the audience's head with the most ease.