There are plenty of marginal gains in flyfishing, I think. The right line, the right leader, the proper rod for the line and type of fishing, being at the right place, at the right time, luck (!), experience, effort, practice and probably more.
I've been incorporating a small "marginal gain" into many of my pike flies the last year or so, and yesterday I was time more as I'm once again heading down to the island of Møn for a great flyfishing gathering, "Session 2017". It's always a great event.
And on Møn there is brackish water with lots of pike in it. And brackish water pike are great fun to catch, and there's the potential of really great days with lots of pike to hand. But - it's also a hard fished fishery, and I really do believe that marginal gains can make a difference in such places.
When it comes to pike flies, possibilities are numerous - due to the size of the flies - wiggle tails, for instance, are very popular these days. And for a good reason, I have really felt them turn a slow day into a great one. When it come sto pike, something that really seems to work is anything they haven't seen before.
Or heard, maybe? I've been using small rattles under the dressing in many of my flies. It's a small glass tube with 2-4 minute steel balls inside and they produce audible clicking. Check the PoD (I'm not done tying it in, but took the shot there so you can see the rattle). The tube also adds a little weight, which may or may not be an advantage - depending on where the pike are holding up.
I'm not entirely sure these rattles make a difference, but I think they can - sometimes. I don't tie all my flies with them. A pike fly is expensive enough to tie as it is. With hook, materials, eyes, epoxy, maybe a tail etc they can easily pass the 5-pound mark before you notice it.
But it certainly can't hurt to try and next weekend, I'll make a effort to fish similar flies with and without rattles and see if I can detect any difference.
Have a great weekend!