Joining two lines, (of the same or different diameters) is very much of interest in climbing, and these knots often do "collapse." The simplest/most common kno

Joining two lines, (of the same or different diameters) is very much of interest in climbing, and these knots often do "collapse." The simplest/most common knot used for this purpose is even named for fishing- the double fisherman's knot. It is used for joining the ends of a cordelette, combining ropes for rappelling or ascending, or in a single ended version, backing up (collapsing on) a knot used to tie in to the rope, such as a figure-eight follow through or bowline. I think you will find that equal to your desire to debate which is the strongest knot is the desire of a climber to not have to think about it- when 100 feet off the deck and on thin footing.