When do you change flies?

[Uncle Jesse]

Why on earth someone would change a fly that's catching fish is beyond me. I've been amazed a few times at some flies that were chewed and ruffled up beyond recognition and still caught fish.

I think the proverbial 64,000 dollar question is when, or how long before, do you change flies that are NOT producing ...?

Back in the days when I was chunking hardware for bass I knew a guy in NW Alabamaistan who would rub his lure on the belly of the fish he or his buddy had caught to pick up scent from the fish. Something he had read somewhere. But I think it may be possible that flies that have caught fish would pickup a fish scent and become more productive. I am also a believer in the cripple look (which I tye naturally) and the predator nature of fish.

Again back in my bass fishing days, a friend would make 10 cast and change lures if he did not get a strike or catch a fish. Of course with a baitcaster or spinning outfit you are covering a lot more water than with a flyrod.