Chrissy brings up some good points about the cast off.  It's  
interesting that I found a definition of gate on a web site that was  
maintained by an English country dance leader.  That definition  
mentions that the person backing up in a gate makes a smaller  
circle.   And, I'm informed by dance master Jim Morrison that the  
gate probably evolved from cast off.
If the person backing up does make a smaller circle, is the pivot  
point closer to the person backing up??
One dancer who used to dance in Nelson in '69 mentioned that during a  
cast off, the men never touched!
Tom