If you fish enough to wear out a fly line over the course of a season, you should absolutely tie a leader to your fly line with a nail knot. The result is a smooth connection that will not only slide through your guides with ease, but also facilitate the best transfer of energy. In other words, casts and presentations will be optimal because there is no hinge point between your line, leader, and fly.
However, if your fly lines last a few seasons or are used in a variety of situations, you’re better off with a loop-to-loop connection. These systems allow for replacing leaders, adding poly-leaders, and making quick crisis management. If you’re prepared, fishing with “loops” means no complex knots while on the stream. All you have to do is thread a leader through two small loops and you’re ready to fish.
But not all loops are created equal. A bad loop will effect your cast and/or presentation. A bad loop will get hung up in your guides, leading to lost fish or damaged equipment. A good loop is a simple and great thing.
Also, I think this is important to mention: With minimal effort you can do better than tying your line and leader together with an overhand knot. I’ve seen it countless times. And I’ve heard the justification of “it’s easy and it works.” But your casting and fishing will benefit from a little extra work. Really, all you need is a few minutes and the knowledge of a simple knot.
Whether you are buying a new line or making a repair, it is worth considering how you’re going to attach your leader. Here are my thoughts on four common loop-to-loop methods:
