I just watched WFN, "The New Fly Fisher",which featured Joe Humphreys on Penn. limestone creeks/rivers.
He was explaining his nymph leaders, using a .017" butt section and his specific casting technique.
He also showed placing a small lead shot on his tippet, after tying an overhead knot in it. This is to keep the shot from sliding down.
Wouldn't the overhead knot weaken the tippet?
I was very impressed with all the info that he offered on the show.
I just ordered his hard copy book, "Trout Tactics" for my F.F. library.