Here it is in a nutshell. Stopping the rod and how it affects loops shape.
The Ultimate Skagit Cast https://vimeo.com/ondemand/ultimateskagitcast The Ultimate Scandi Cast https://vimeo.com/ondemand/327236
This Video shows how one of the worlds finest distance casters, Geir Hansen, stops the rod.
Steve Rajeff explains distance casting with a single hand rod including the technique he uses for stopping the rod.