I've always been inclined to untie the back-up figure 8 from Tom's biner block diagram after all but the last are off rappel as I consider it added risk for sticking a rope. Do you all untie or leave it in place prior to the last person and for the pull? http://www.canyoneeringusa.com/techtips/wp-content/uploads/2012/04/binerblock1.jpg Click for original size I have always assumed that the knot (overhand, double-fishermans, etc) between the rappel line and the pull cord would provide adaquete blockage given a slip in the clove-hitch. Do you all consider slippage in a clove hitch with climbing rope a real possibility? I've heard that it is possible with a clove hitch that isn't dressed out well or with a rope if it is stiff/new.