I firmly believe most strikes when fishing wets upstream are missed by most fly fishers... The ratio of known hits and hookups is high enough with swinging flies to maintain interest but surely not the most effective way to catch fish.

My son, while quite young, and I had many days of fishing for grayling where we played with the presentation. The fish are so aggressive it makes little difference how they are fished the strikes will come. Sensing them becomes the difference.

Using flies like Gummie stonefly nymphs works better because they hold the flies longer, increasing the chance of being hooked.

Using indicators increases hookups because fewer takes are missed.

Learning to control the fly, keeping a reasonably tight line, while fishing under conditions where takes are hard to feel will help a great deal also.
art