Swirl Knot

Source of description unknown. I discovered it while surfing the Internet. 

 Paul Dubas, at that time a guide on the Bighorn, taught it to me, but he tied it with two hands. He called it a Swirl Knot. I’m going to try to describe the knot, but without photos, it’s really tough. Tied with two hands, this is basically what you do:
Thread the tippet onto your fly, slide it down the leader a couple of feet and forget about it for now. Make a slip noose in the tippet. Put your hand through the loop, grab your fly, and pull the fly and tippet through the loop. Then tighten the loop around the eye of the hook.

The one-handed version requires that you learn how to tie a slip noose in your tippet with only one hand. Not only is this a valuable skill for tying on flies, but, it you fish with a yarn indicator, the slip noose can be into your leader at any point without removing flies or cutting anything. Furthermore, after you’ve removed the yarn, simply pull on both sides of the knot and it will come out, probably leaving a kink in your leader, but not doing major damage.
Here’s the one-handed method.

• Pass the tippet through the eye of the hook, hold the bitter end of the tippet in your right hand, and let the fly slip down, perhaps a foot or two.
• Put your left hand next to the hanging tippet, and turn it over, so that you now have a loop of tippet around your hand.
• Without removing the loop around your hand, grab the standing part of the tippet with the thumb and forefinger of your left hand. Now “throw” or “shrug” the loop that is around your hand over the standing part of the tippet which you’re holding between your fingers. At this point, you should have a loose slip knot. Tighten it, but not too much, against the standing part of the tippet.
• Put your left hand through the new loop (created with the slip knot) that you’ve just made and grab your fly with your thumb and forefinger. (The right hand has never let go of the tippet end, or even moved to help the left hand).
• Now “throw” or “shrug” the loop off the front of your hand, while still holding onto the fly. This will create a second slipknot.
• Now snug up those two slipknots until they are tight against the hook eye. You should be able to pull the knot away from the eye of the hook.
• At first, you will find that you use way too much tippet, but you will discover how to snug the slipknots up in such a way to have almost no wasted tippet, like an inch or less!
• You need to practice this with a piece of twine or old flyline in front of the TV for awhile until the moves become second-nature. The knot tests about 87% breaking strength. The bitter end of the tippet never has to be passed through another small hole like in a clinch knot. You’re far less likely to weaken your tippet by “burning” it when tightening the Swirl knot than with a knot with multiple coils over itself. Once you successfully thread the fly on the tippet the first time, you never have to look at the knot again, at least not until you look at it to trim away excess tippet. It’s great in the evening!