Several years ago I had the pleasure of doing a fly swap with a fly fisher in Japan. Satoshi is a very good angler and fly tyer. He sent me several flies of two patterns. One was a thorax dun, and the other a Royal Coachman Parachute. Over the years I have fished them both but the parachute far out fished the other.
Now I am down to just two of those parachutes, the others are lining the banks and trees along several trout streams.
Not wanting to loose the remaining flies, I wish to keep them for my collection, I attempted to tie the pattern myself. While it's close to Satoshi's it's not the same. He is much better at wrapping and tying the hackle

Well yesterday I spent a few hours on a small wild trout stream. I was armed with the RC parachute. The stream was ever so clear, but with a mixture of clouds I was able to move without spooking every fish. As that fly did it's drifting, it brought the trout to the surface. There were many many takes and I even managed a few to hand.
As the day ended I was to leave with my one fly. It had not succumbed to the streams defenses but it lost some of the magic material the peacock herl.
I love these guys. They love the Royal Coachman Parachute.