Originally Posted by Satchel
I could resist, but not very easily, so here goes. If you were to diagram your cast by placing a dot at the tip of the rod when it reaches it's furthest rearward movement, and place a dot at the rod tip at it's point of forwardmost movement, and draw a line between the two dots, extending that line forward to infinity, you will have a pretty good diagram of the plane of your cast. By the same token, if, during your forward casting stroke, the tip of the rod, due to the amount of force applied resulting in flex in the rod, dips below that line, you will most likely end up with a tailing loop.
So much for my amateur attempt at the physics of the fly cast. All scientist and engineers are welcome to fire away, I'm well armored.