Tying a knot on a bight has value in many applications.
Examples include tying a binder around a bag opening, ...
I'd say that this is a case where --often, at least-- one does
NOT want to form the binder in the bight, as that would
entail consuming much material to amply open the binding
to accept the bag before tightening it; whereas if one can
begin with a short end, then work the rest around to close
quickly, the material can be cut off to leave only another
short end (and not two long ones). The
ground-line hitchis a miller's knot that can be so formed; the casting a
half-hitcharound the bag opening is usually easily & quickly done and
drawn tight.
--dl*
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