Phil, you've been around since then, did you ever read my old Animation Primer? I dealt with exactly this question. I don't have it anymore, that was a number of years ago, but I'm working on a comprehensive cd full of animation tutorials right now. Anyway, you've got the right answer, Phil, (as a matter of fact I'm going to experiment some more with broken splines myself now...)but I want to clarify: A lot of people suggest this very thing, that using Linear(Orange Spline) interpolation is the best way or even the only way to animate. In reality, linear interpolation is really just there to replicate mechanical movement. For organic movement, you have to go with Spline (Green Spline) Interpolation. But the problem most beginners (And some experts) have, is keyframe positioning. If You have two keyframes far apart, (shown here on frame 1 and 15) and then you put a keyframe close to one of them (Frame 17) there's going to be a huge unwanted peak in the middle (right around nine and ten). While it's true that linear interpolation would not give you this peak, It also won't give you the "Ease-in/Ease-out" necessary for realistic organic animation. A better solution is shown here: Adding in keyframes in the middle (frames 9 and 12) lessens the peak and gives a rather natural motion. The overswing is still there on frame 14, but now the arc is more natural, and the forearm no longer bends INTO the upper arm, vanishing. Another possible solution to this problem would be to move the keyframe on frame sixteen, but sometimes you'll need very quick movement. Another thing to remember is that the curve of the spline will tell you how fast the object is moving. If the spline is shallow, almost horizontal, the object is moving slowly. If it's steep, nearly vertical, the object is moving very quickly. Now for my question: Phil, what do you feel are the advantages of breaking the spline, and could you give a breif example of when and why you would break it?