I use 6-X flurocarbon tippet material for big fish and have experienced a great number of knot problems. Basically, I use a 16/20 for the fly and a Blood or Orvis knot for the tippet connection. I'm amazed at the inconsistency...sometimes the knots hold like iron; othertimes they break like butter! Mostly it's the 16/20 which is supposed to be close to 100%. This inconsistency is evident both on the stream--which is understandable--and on the testing bench which is not understandable. The knots are all lubricated with syliva and tightened with a slow pull to eliminate heat build-up. True, my testing methods may not be professional, but neither are the conditions on the stream.

The tippet brands I've tried are Airflo G3, Orvis, Seagar and Frog's Hair. I've come to the preliminary conclusion that each brand has knots that work best with it. But I'll be damned if I can figure out the best knots for each brand. I'm also thinking that going back to monofilament might give better knot breakage results. Problem is I believe everything I've read and heard about the advantages of fluro.

Does anyone else done similar tests and experienced such inconsistency, or do all your knots break at pretty much the same rate each time?