Re: Favorite "loop" knot?
I don't use loops on either crab or shrimp flies except for shrimp flies with the eyes on the point end of the hook. Crabs move is a straight line, though often with abrupt angular changes in straight-line direction, when fleeing. They don't wiggle when swimming.
I've found that shrimp patterns with eyes forward are best fished with long, very slow strips in no current, and simply swept on a tight line in current without strips like fishing wets for salmon on a river. They don't wiggle when swimming either. When alarmed, they jump all over the place, including into the boat - but then, they are moving backwards.
Loop knots I use when fishing streamers, usually for big fish, with 40 lb or bigger shock tippet. Knot strength on them is irrevalent and even at only 60% still usually (or at least often) exceeds the strength of the fly line itself. So I don't think it matters much what loop I use for strength. All of those mentioned work fine.
But because bay grass fouling is often a problem where I fish, I've started using Lefty's loop, but with the tag going through both "eyes" of the partially closed surgeon loop.
It is a real PITA knot to tie because the loop, the tag and the standing line all have to be tightened together. I get the best results with two pair of pliers and a hook ring. But the result is a very slim knot with the tag laying back directly toward the hook eye.
But at least one pair of pliers and a hook ring are necessary anyhow for tying good loops in heavy shock tippet.
Davo, sounds like a "Homer Rhodes" you are describing, but it is not a "half hitch" but an "overhand knot" that you tie around the standing line with the tag at the end.