Thanks, Sam that answers the question. The demonstration shows what I learned as a "hasty sling".

For me a hasty sling is no where near as helpful in shooting as a military sling -- but that may not be true for others. (Believe me I need all the help I can get; most of my shooting at game has been from the sitting position with a tight military sling.)

"It is wise, though, to remember above all else: rifle, caliber, scope, and even bullets notwithstanding, the most important feature of successful big game hunting is to put that bullet in the correct place, the first time!" John Jobson