Arbor Knot for tying the backing to the arbor, Albright Knot for tying the line to the backing, a Needle/Nail Knot for tying the leader to the fly line. Most lines today are equipped with a loop, which I often use myself, because leader change is fast and convenient. In that case, a Perfection Loop is the best. Finally I use three different knots for tying the fly to the leader. That seven knots, a little more than a handful.
If you look, you can find lots of information on which knots retains the most of the leaders breaking strain. Remember that the breaking strain of monofilaments is always weakened by a knot. Some knots claim 80%, some more, some less. I’ve honestly never given that much attention, although I’m sure than a slight gain in knot strength is important in fishing for really big fish. Which ever knots you decide to use, learning to tie them well. That is more important than a few more percent of strength. I choose the easy ones, because once a knot slips, even ever so slightly, is fails.
The three knots for tying on flies I use are the Blood Knot, Rapala Loop Knot and a Turle Knot. The Blood Knot is the easiest and not that long ago without my damned readers. I still can on heavy monofilament, but if needed, use the damned readers so you can properly see the knot. The Rapala Loop Knot holds the fly in a loop (hence the brilliant name) and it’s also easy to tie.
The trickiest once is the Turle Knot. And no, it’s not called a Turtle Knot. It’s named after a Major Turle, who is credited with coming up with the knot, it’s believed to be the strongest of the three, but that’s not why I use it. It’s only used on up eye hooks, because the knot doesn’t grab the hook eye, but the shank of the hook. That is why it’s important to leave a little room behind the head of the fly and eye, so it has room to grab. That means that the knot steers the fly, ensuring that the fly always fishes in a direct extension of the leader, in lack of a better term. It was the main knot used “in the old days”, when most of the eyed hooks were up eye designs. Some dry fly fishers still insist on using it, because when a traditionally hackled dry strand properly on the surface, the knot lifts the leader off the surface closest to the fly.
I use it on the salmon flies I tie on hooks. You can argue that keeping the in line with the leader is an advantage always, but so many hooks are designed with a straight eye. A Blood Knot does provide some steering ability, where as a loop knot (there are several to choose from) allows more movement of the fly.
I also use the Turke Knot when I fish single hooks behind my tube flies (I never use anything else now). My preferred tube single from Harex Hooks has a straight eye. The tubes I use for the medium to big tubes flies have a big enough diameter that I can simply secure the fly in the tube, keeping it inline with the fly and leader. However, this hook doesn’t come smaller than a size 8 and that’s too big when I fish the really small tube flies.
The tube a 3mm long and the hook is secured with a Turle Knot.
In this case, I use a Turle Knot, because my preferred hook for the minute tubes is a stinger hook with a up eye. I use tubes from Pro Sportfisher that are designed for small flies and equipped with a small tap that accepts a Hook Guide. A Turle Knot with a Hook Guide makes sure the the hook is always pint down, away from the wing, almost eliminating tangles, even on flies with long wings.
Finally, I also use either the Perfection Loop or the Rapala Loop in a big/long loop, if I want to push the hook further back from the tube. The diameter of the small part of the tube is small enough that the knot itself stops the tube from sliding back. I simply loop the hook onto the loop.
That became longer than I intended. If you want to keep it short, learn the Arbor Knot, the Albright Knot, a Perfection Loop and a Blood Knot.
Have a great weekend!
PoD: A large tube with a stinger/trailer hook pushed back into the tip of the wing, by securing the hook in a Perfection Loop that stops the fly from sliding back to the hook.