A couple of weeks ago Tom Rosenbauer wrote about why you might impart drag to a fly as an obvious signal to trout that it is time to take a fly. But Rob Brown makes a subtle distinction between intentional drag and the imperceptible drag that he says can also stimulate feeding. Heresy, you might say. But it’s an interesting theory. Is it possible that trout are reacting to imperceptible drag more often than not? “The fisher has made a good throw and a fine, long drift. At the physical limit of that journey, the fish is almost convinced, that is, there hasn’t been enough stimulus to trigger the fish’s finely honed instinctual response. At that precise moment, the time when the fly is about to drag, it begins to speed up, suggesting that liftoff is imminent, and at that critical juncture there is sufficient stimulus to provoke a rise and take from the trout.” In BC’s Terrance Standard.