The strongest and simplest tippet to fly knot there is is the Pitzen knot.
The Pitzen Knot is referred to under a number of different names including the Eugene Bend, Pitzen, and the 16-20 knot. Lefty Kreh was very familiar with this particular knot and adept at tying it, he referred to it as the Fisherman’s knot and reckoned it had been around since the 1950s.
LINK (via Epic Fly Fishing)
