Loops & Nooses - Butterfly Loop or Lineman's Loop
Butterfly Loop or Lineman's Loop
This is my favorite loop knot tied in the bight. It's secure, strong, approximately symmetrical, easy to tie, and never jams, even when wet.
There are actually two good ways to tie it, and the easier way is shown here. The other way works better when you don't have as much slack to work with. You should use this loop often, so learn both methods.
This loop is also the starting point to one of the best double loops around.