Fulling Mill CJ's Controller

One fly, and you decide what it is

The name is the instruction. A slim thread and wire body, a small bead and a sparse hackle add up to something with no strong identity of its own, which means how you fish it determines what a trout takes it for: an emerger in the film, a soft hackle on the swing, a static nymph under an indicator, or a midge pupa on a slow draw. That makes it a genuinely useful fly to have on when you do not yet know what is happening.