Just to provoke thought, one from the 'darkside' in antithesis to Siegers perfect 1 -1.5 hackle turned (?) 'traditional' NC style Waterhen Bloa. Traditional N.C exponents look away now:
Although I do like the sparse hackles, I like using denser hackled spiders like this for fishing in faster, streamier water, and often letting them go round 'on the swing'. My theory being that the hackles activate more and 'close up' under water tension as the fly rises up thus resembling a nymph. I got myself a new A-hole torn by a NC spider expert for suggesting this on a UK fly fishing forum as, according to his extensive research, this doesn't happen. I am not so sure about this. Coulda been worse - I might have shown him this flee ! Anyway have taken a lot of fish using this method when there is no rises and you usually lose a few barbs per fish so the fly does get 'lighter' in the hackle.
This one only has two and a half turns (of Coot) but I didn't strip one side. Pearsall's No.4 (waxed) for body, sparse mole dubbing and Mustad R50 hook size 14 (barb crimped).
My best spider last season. A Black Pennell hackled this way, for me, has been deadly for trout and Sea Trout.
Lindsay