When should you change the fly?

by | Apr 25, 2019 | 6 comments

My buddy, Smith, is stubborn. Whether he’s traveling across the country or fishing our local rivers, he fishes the same handful of flies, year round. Smith can literally hold his selection of nymphs, wets, dries and streamers in one hand without them spilling over. With patterns that are fine-tuned from experience, and a selection ruthlessly stripped down to the bare bones, his handful of hooks is the very definition of confidence flies.

Smith’s trust in those patterns is so spot on, you might assume that he rarely changes flies. But you’d be wrong. Ask Smith, and he’ll tell you he changes flies whenever it’s necessary.

Now, what does that actually mean?

READ: Troutbitten | Fifty Fly Fishing Tips: #25 — Confidence is King — Find your favorite fly theme and vary it

I’ve pared down my own selection of flies, after finding that too much choice is better for making excuses and wasting time rather than actually catching more trout. Keep things simple, and good things will follow.

I might need two hands for my own collection though, if only because I have an endless inclination for testing things. So half of the space in my fly boxes is dedicated to the next experiment — the next variant. I’m always looking for a new confidence fly. And it takes a few seasons to resign myself to a fly’s failure before kicking it out of the box. Remember: everything works sometimes.

So let’s consider this persistent and perpetual question: “When should I change the fly?”

I think it’s important to be confident in what you carry in those fly boxes in the first place. My point? Find a reason to believe that the next fly is the necessary solution — that the next fly solves a problem and shows the trout exactly what they are after. And if you don’t have such a reason at the ready, just keep fishing the fly you have on. (It too should be a confidence fly.)

Reasons at the Ready

My guided guests are often surprised by how much we change flies. So I always provide a rationale — my line of thinking — behind the switch.

If we’re nymphing, the change is often nothing more than a consideration of weight. If we’re riding too shallow, then let’s tie on a heavier fly. Pretty simple.

Under the water, I might change flies because I want a different bead color or a different type of flash in a nymph or streamer. Have we shown the trout copper beads and dark brown nymphs? Then let’s try something with a black bead and light Hare’s Ear dubbing with a hot-orange collar. Did we strip some flashy streamers through likely holding water? Then let’s get away from the ice dub and Flashabou. Tie on a streamer with more somber tones, and run it back through the same lie.

On the water’s surface, my approach is similar, but the decisions are often centered around fly size and on-the-water profile. Specifically, I swap out dry flies that ride either in or on the water’s surface. A fly like an X-Caddis lies flat, while a traditional Elk Hair Caddis dances on its hackle tips. Trout take them both just as well. But day to day, one or the other performs better. Up top, I believe color is the least important dry fly variable, but the general shades of light or dark can be very important.

Whatever the fly type, and whatever part of the water column you’re targeting, there should be a reason for every fly change. The next fly should solve a problem, or it should test an idea you have about what the trout are really looking for.

Good anglers have a theory about everything. The best anglers keep an open mind and trust the fish when they disagree.

READ: Troutbitten | Pattern vs Presentation — Trout eat anything, but sometimes they eat another thing better

WD40. I love it when they eat the small, natural stuff.

When the trout say no . . .

Don’t change a fly until you’ve effectively fished the one you have on. That’s my guiding principle, so back up and read it again.

All you carry are confidence flies, right? And you have a good reason (a theory) for tying any fly to the end of your line. So you only need to change flies if the trout disagree.

I change up when I know I’ve gotten excellent drifts over a few trout, but they still haven’t taken it. It’s a simple philosophy. However, the key is to recognize what an excellent drift really is — and to understand your own river enough to know when you’ve presented the fly to a few trout who have surely rejected it.

Most often, good anglers change the presentation before changing the fly. Refine the drift. Work from another angle. Get the nymph deeper with a tuck cast, or place the dry a little further upstream of the rise form. Get the most out of the fly you have on first. Show it to the trout in a few different ways, and get a perfect drift.

Do they still say no? Then let’s change the fly.

Fish hard friends.


Enjoy the day.
Domenick Swentosky



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Domenick Swentosky

Central Pennsylvania

Hi. I’m a father of two young boys, a husband, author, fly fishing guide and a musician. I fish for wild brown trout in the cool limestone waters of Central Pennsylvania year round. This is my home, and I love it. Friends. Family. And the river.

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  1. Oh, to walk into the stream with only a handful of flies! ( instead of the few thousand in my vest, shirt pockets and waders). The quest to whittle it down is an ongoing process but once again Domenick, you’ve given me hope with great advice. Thanks!

  2. Dom, I am new to your website, but already loving it! I agree on the confidence flies, I don’t like to carry a lot because frankly Im not a kid anymore. At the age of 61 I really think things through before I do them, and since I fish alone I tend to be pretty specific about what I carry on my back. Less is better for me, I really appreciate the info on your blog, keep up the good work, and yes fish hard.

  3. When to change a dry fly/emerger when fishing to a surface feeder?

    This question should be preceded by, “Which fly should you start with?” The right answer to this can eliminate a lot of fly changes.

    The sheer variety of rise forms and rhythms combined with insect specie/stage (along with terrestrials) makes for the kind of analytical challenge that is as rewarding as it is addicting. And it explains why few dry fly guys can get away with a small handful of dry fly/emerger patterns; especially on bug rich, highly pressured systems like the Upper Delaware.

    As my fly fishing mentor liked to emphasize: fix your casting (drag issues; overlining, etc.) before you even think of changing your fly.


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Domenick Swentosky

Central Pennsylvania

Hi. I’m a father of two young boys, a husband, author, fly fishing guide and a musician. I fish for wild brown trout in the cool limestone waters of Central Pennsylvania year round. This is my home, and I love it. Friends. Family. And the river.

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