Hmm. A few thoughts. There are alternatives to the Prussik such as the Klemheist which don't jam as badly. I wouldn't use a ring bend - the double fisherman's is superior for tying rope or cord ends together to create a sling. And I definitely wouldn't use either a ring bend or a double fisherman's to link ropes for abseil. An overhand tied in both ropes (with a 50cm tail) -aka the EDK or European Death Knot is way s…
Fair point re: the Klemheist although the Prussik serves well enough. For my part I wouldn't use a figure 8 in a bight to get a loop in the middle of a lonf rope that's going to take load - the butterfly knot is far superior.
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