Fly casting has a lot of moving parts. Two sets each of arms, wrists, hands and fingers all work together to flex the rod and propel the line with flies to the target. There’s a lot going on. It can feel overwhelming — like sitting behind a full drum kit for the first time and realizing that all four limbs have a responsibility to do independent things.
So it takes a while to get all those parts working together in concert. But anglers and musicians alike need only understand the basics and then put in the playing time. Given enough practice, good things follow.
I’ve noticed that the most overlooked aspect of those moving parts is the trigger finger. I meet anglers with all manner of bad (inefficient) habits that hold them back. But the trigger finger issues are easily solved, because there’s not much variation with its job.
In fly casting, all movement of the line should come through the trigger finger . . . with limited exception.
Index or middle?
Does it matter which finger is the trigger? No. It doesn’t. I prefer to hold the rod with my index on top, so my middle finger becomes the trigger. Most anglers prefer the more common method of thumb on top of the cork, and they use the index finger as the trigger. There are good reasons to choose both, of course, and we’ll talk about that another day.
Either grip works, and the principles for the trigger finger are the same. Whatever rod grip you choose, the trigger finger has a job to do.

Index on top

Thumb on top
Trap it
Take a look at the line. Following it down from from the rod tip, the line should come through the shooting guide (the closest one — the larger one) and underneath your trigger finger.
That’s the default position. That’s the position the line should be in most of the time.
Trap the line against the rod cork, and keep it there until you are either retrieving line or shooting line. Then simply lift the trigger finger and allow the line to pass through.
I meet a lot of anglers who don’t do this. Instead, their line goes from the shooting guide and straight to the line hand. But this doesn’t work nearly as well.
Why?
When the line at the trigger finger is tight, it’s ready for a hook set: the trout strikes, the trigger finger traps, no slack, set. Fish on.
If instead the line passes from the shooting guide to the line hand, there’s way more slack in the system. Even without any apparent slack drooping from hand to guide, that extra line must come tight before the hook is driven home. A small difference? Sure it is, but everything matters.
Also, it’s impossible to strip line without using the trigger finger. You can pull back with the line hand, but without the trigger finger to trap the line, you can’t let go and re-grasp further up for the next strip.

This is not good.
That leads us to the hand off . . .
Shoot and then hand off
While shooting line through the guides, the trigger finger lifts up after the power stroke and allows the line to pass through (much like stripping line in).
Small lengths of line can be shot right through the lifted trigger finger. I do this to shoot a foot or two of line.
If you want to shoot long lengths of line that sail to the target, it’s best to release the line from underneath the trigger finger completely, and allow the line to pass straight through to the shooting guide.
Immediately after the cast though, the line hand should grab the line somewhere behind the shooting guide and give it back to the trigger finger.
After the hand off, the trigger finger is again in full control of the line through the drift. It lifts and closes in concert with the line hand to retrieve while stripping a streamer — like the high-hat on the back beat of a four count. Or it lifts to slowly recover slack on a dry fly drift — like swirling brushes on a snare drum.
The trigger finger becomes intuitive if you train it in the basics from the beginning.
Fish hard, friends.

Photo by Bill Dell
Enjoy the day.
Domenick Swentosky
T R O U T B I T T E N
domenick@troutbitten.com
“Keep it on the reel” is a way of life here in Alaska. You’ll get line cuts on your finger/palms/wrist you’re not likely to forget. When i fish Tenkara i have to repeated tell myself to point the rod to the sky and let the 5x tippet break ( it generally does before the tip breaks !) If you point towards the fish … you’ll never get the pull apart ferrel unstuck. Still … nice to have these problems (8->}. Keep the articles coming … i honor the light that shines within you.