Quote Originally Posted by John_N View Post
when I do use shot, I do something a little different to prevent it from slipping without weakening it by putting a knot in the tippet. I lay the tippet in the open groove of the shot, then loop it under the shot and back through the groove again, then close it. That doubling over prevents the shot from going anywhere, but when I take the shot off, there's no knot to worry about.
This is what I do also.

An overhand knot or wind knot is the worst knot to have in the leader. It cut's through itself and weakens the section it is in.

"Overhand (Figure G-2). This is the simple knot that most people tie everyday as the first half of tying their shoes. It can also be used to temporarily whip the end of a rope. This knot should replace the half-hitch as a finishing knot for other knots. This knot alone will reduce the strength of a straight rope by 55 percent."

http://danger.mongabay.com/survival/afm/g.html

This is a quote from an Orvis Blog that is no longer on-line:

"Typically, an overhand knot, the most destructive knot you can tie in tippet material because it has the most extreme bend, weakens nylon by about 50% of its rated strength by weakens Mirage only 25% or less."