In New Zealand, where the waters are typically very clear, and the trout are always very smart, the exact spot where a fly lands near a trout can matter down to the inch.
The Kiwis will tell you that as you are casting upstream at a fish’s position, it’s always best to miss to the current side of the fish’s position, rather than the slack, or bank side. Sometimes you intentionally want to stick the fly off to that side. Indeed, there is nothing quite like watching a 10-pound brown trout take notice of a fly floating 12 feet away and off to the side, swim over, and grab it.
The chances of that happening are often better than they are when the fly lands right overhead, or even if merely the tippet is directly overhead.
Guide Nic Robertson explained to me like looking at the back of a truck. The trout is swimming several feet behind the truck, centered as if behind the license plate. The shore is to the left side. The main current is to the right. Your target is the right-side tail light.
— Kirk Deeter