I caught 5 slot rainbows and 1 slot brown at the church working the seams with a pheasant tail soft hackle 12" below a yarn indie and a modified PT nymph on a dropper 6" off the bend of the softie. ALL fish took the nymph. Later, as the birds started working, even with nearly no adults to be seen, fish started smashing my soft hackle when fished alone and swung down and accross. This was yesterday(tues).
Not sure what Corbo meant by 'behavioral drift' but perhaps the nymphs are going through an instar where they shed their shuck in favor of thier new body growth. No matter, the trout certainly must notice. In Shawns' video, trout can be seen swiping what appear to be nymphs in mid water column. I seldom, on the Clinch need to suspend a nymph below and indicator more than 24". More often than not, merely 16" is adequate to get the bite. I use as small a piece of yarn that I can get away with. I realy like that Loon Outdoors "Strike Two" yarn in flourescent chartruese/yellow or whatever that color is. The stuff floats like no other and needs NO treatment to keep it floating. I often save the used pieces and get another round out of them!
here's a recipe for my most successfull "sulpher" nymph to date:
Hook: TMC 3769 sz 14
Thread: 8/0 yellow UNI
Tail: wood duck fibers, fanned
Abdomen: palmered natural pheasant tail (about 4 fibers only)
Rib: Hot Yellow Ultra Wire sz small, counter wrapped
Thorax: Hares' Ear dubbing; mix of all hair from the mask tied in a loose dubbing loop
Wing Case: natural colored slip of Canada goose wing secondary coated with Salley Hansen's HAN
Head: gold sz 3/32 tung bead
Hint: Tie this nymph slight, as if it were being tied on a sz 16 hook