The “strike zone” is a term in fly fishing that refers to the area in the water column where the fish are striking. In fly fishing, most fish will only hit on flies that are in this strike zone. Many things affect the strike zone, including the water clarity, weather, type of food the fish is eating, and other factors.
A split shot comes in handy when an angler needs to add weight to their fly rig. This helps get the fly into the strike zone quickly so it can spend more time in the strike zone during the drift. This gives the angler the opportunity to catch more fish.