Recently, a friend and I were working down a short non-descript run known to put out fish, I was going first and he was following with a faster sinking fly and longer tip. Halfway through the run, I felt the ineffable mouthings of a steelhead then a growing tension--and I struck. The fly pulled free and the fish wouldn't come back.
In the minutes and hours that followed, I couldn't help but second guess myself: I should have waited longer before striking.
Just moments after my grab, my friend felt one of his own. His came as a tug, tug, growing tension, then headshakes, and then the fish spit the fly. He said in the let down of the miss: I should have struck when I felt those headshakes, I shouldn't have waited for the fish to turn.
So there we were, two steelheaders second guessing themselves and their theories of when to set the hook.
When I speak at fly fishing clubs and at expos, setting the hook is among the most common question category. Every steelheader I know sets the hook on instinct. Some, like my friend mentioned above, wait until the fish turns to run. Then when he pulls, the hook finds solid purchase. Others, like myself, have no firm rule. Sometimes, like when the fish is directly below me, I wait for the fish to turn. Other times, like when a wide belly has formed in the fly line, I strike as soon as I feel growing tension.
But three maneuvers, I've found, dramatically increase the likelihood of solidly hooking steelhead. 1) I keep the drag of my reel tight, tighter than it will be during the final stages of the fight, so when the fish comes tight to the reel, the hook is "set" automatically. 2) Except in bizarre situations (heavy shoreside brush, for instance), I always strike toward the downstream bank, increasing the likelihood of a firm hook placement. 3) I use a striking loop only when I'm fishing a narrow seam directly downstream of me; the loop will give the fish time to turn. If I'm fishing a more traditional run, I skip the loop because I want solid, immediate tension when that fish takes.
I still miss my share of grabs, but that's steelheading.