Not long ago I speaking with an angler and fly tyer who I hold in the highest regard.  During our conversation I said, “I can think of a dozen knots an angler can use for tying his fly to his leader.  Is it all that important what knot you use, or can it be any knot so long as it doesn't slip?  What is the relevance of the knot used for attaching the fly hook to the leader, other than to ensure that the fish doesn't get away?  Can you answer this with less than a hundred word?”

His response to my question was,  “The most effective fishing knot is, The Turle Knot, where the leader is slipped through the eye of the hook, up for up-eye, down for down-eye, a simple overhand granny tied at the end of the leader as slip protection, then another overhand granny  tied around the leader then the fly is slipped through the loop created, then tightened around the eye. This allows the fly a free, unobstructed swimming motion without imparting a wake when fished.”