How Closely Should You Match the Hatch?

Whether you tie or buy your flies, it’s tempting to think that if you’re not catching fish, one reason may be that your fly does not match exactly what’s transpiring in the water column. However, the Law of Diminishing Returns seems to apply to how closely you need to match the actual insects. Here are six mostly true statements about matching the hatch:

1. Trout are not like us.

While there are days when I think my teenager may have a single digit IQ, it’s more likely true of trout. No doubt that big brown is wily, but its feeding pattern seems to be driven largely by an evolutionary algorithm that takes into account calories divided by energy. The numerator always needs to be greater than the denominator.

Ergo, the calories need to be worth the effort.

While we may worry that we don’t have the perfect fly for any given situation, the trout may be ignoring what we’re casting for a different reason other than it is not the exact bug that is rolling along the bottom, emerging or hatching on the surface.

2. Some flies work everywhere.

A wide variety of nymphs are highly effective anywhere where trout are found. That’s no surprise, I’m sure.

Just to name two old standby nymphs: the Pheasant Tail Nymph and the Gold Ribbed Hare’s Ear. These are just gold, pretty much in any cold-water fishery across the world.

And then there’s the trusty, old-and-tired Parachute Adams, your grandfather’s dun pattern. In various body colors, this fly can represent nearly all the mayflies, caddis, and midges that are emerging at the film, where the adult pulls itself free from the pupal skin.

The Parachute Adams is not sexy, but it works. Somehow, the trout find it strike-worthy even though it isn’t a perfect match to the BWOs that are popping.

3. Suggestion is more important than imitation.

In fly fishing, the “close enough” principle seems to be at work.

I’ve been surprised how even a Colorado fly like the H & L Variant, a high riding attractor pattern, fools trout on the Driftless streams in the Midwest. It can be used to imitate Green Drakes on the Frying Pan in Colorado as well as the Crane Fly (also known as “leather jackets,” “daddy-long-legs,” and “skeeter eaters”) in the Driftless.

Perfection is not the end game; catching fish is.

4. Color and size trump the perfect match to the hatch.

This morsel of fly fishing advice is as old as the river you’re fishing, but it holds true and is worth repeating:

If you’re not catching fish, try a smaller fly. Or change color. That’s especially true with dry flies, but it also is true of nymphs and emergers.

On one fly fishing trip, I couldn’t figure out how to catch browns on a stream in the Driftless region during a caddis hatch in early May. It’s not like I’d never catch a riser, but I’d land one or two when I thought I should have caught ten or more. I finally grabbed an adult caddis one morning and analyzed its coloring. It was largely black. Then I looked at what I was casting – a tan-bodied caddis pattern.


I picked up some black-bodied caddis later in the afternoon, and the next morning I was golden. Or at least more golden than I was the day earlier. I also dropped a size #18 Olive Serendipity about eight inches from my dry fly. The emerger seemed to work when the browns refused the adult caddis pattern.

5. Less is more, and more is more.

The knowledge that fish tend to prefer suggestion over imitation can help you simplify the number of patterns that you carry. Less is more as it relates to carrying all the possible flies for each hatch.

And more is more as it relates to color and size.

6. Some trout are more picky than others.

That’s certainly true on spring creeks, with even flows and temperatures, clear waters, and seemingly an unlimited food supply. You always need to refine your tackle and techniques when fishing on spring creeks.

Also, if your stream gets slammed during certain parts of the year, with fly fishers at every bend, fish seem to appreciate more precision or a different look.