I used two different sized hackles on this fly. A shorter one at the mid-point of the hook than that used fore and aft of the wings.
It seems more in line with the insect’s leg positions. I did it to see if it might also add a bit to the stability of the fly. It seems to, at least on the tying table.
Joe, Not to bore you, but I tied another slightly different pattern which might make it easier to see. I think, if the hackle at the mid-point isn’t shorter, the fly would tend to tip forward and lose the float line.
Anyway, I think this shows the different lengths of the hackle fibers?