I usually retie if there's any doubt or a knot looks even a little wrong, but like Dillon, a summer steelhead proved to me that even if I have a bad feeling about a knot I should retie.
I was on the N Umpqua on a July morning and sunlight was starting to hit the water. I hurried to tie on a new fly before the sun hit the water. I use a non slip loop, but something felt wrong when I cinched it down. It looked ok, though, and I was in a hurry so I went ahead anyway. In ten years of fishing the river I'd never hooked a fish in that little pool anyway, it was just fun to swing a fly there. About a dozen casts in a steelhead absolutely hammered my fly, cartwheeled, set out on a blistering run, my backing knot shot through my guides, and then everything went slack. I reeled in and looked at my tippet. My nonslip loop had slipped. No pigtails, just the little overhand loop and a inch or two of tag end. I laughed because I knew it was my fault, but on a river where one hookup a day is good fishing it was a bit disappointing. I think about that fish a lot when I'm tying on a fly even though it was several years ago.
