Why a jigging spoon works on the drop
The lift of a jigging spoon shows the fish nothing: the lure just follows the line straight up. All the action happens once you stop your hand — on the free fall.
What the lure does once it's released
The plate doesn't fall straight down: the water presses against its flat face, the lure tips sideways, rolls, and works its way back under the tie point. The result is an arc or a zigzag — and the wider the body, the longer that arc runs.
Slack line is essential
On a taut line, the fall turns into a pendulum: the lure swings in a circle around the rod tip and shows nothing at all. So after the lift, you lower the tip along with the lure — the free run is exactly what you're letting the fish see.
Where it goes on the fall
The body's width sets how far the lure drifts; the balance of its mass sets whether it drifts sideways at all. A wide, light plate glides a long time. A narrow, heavy one drops almost straight down, and fast. It's not better or worse, just different jobs: one searches the circle under the hole, the other gets back to the working depth fast. The same lure becomes a glider or a “nail” just by shifting the mass inside it — with no visible difference outside.
What kills the action
Thick line resists the water and shortens the arc. A heavy snap or swivel at the nose does the same. The quietest fault of all is a knot pulled into the corner of the hole in the nose: the lure stops rolling freely and falls like a plain sinker.
The pause at the bottom
After the fall, the spoon keeps rocking, and a hook on a ring or a chain keeps moving even once the body has stopped. This phase runs noticeably longer than it feels like on the ice, and it's exactly what gets shortened when you pick up the pace.
How long a cycle takes
The lift itself takes an instant, the fall takes longer, and after it stops the lure keeps rocking a while more. So counting the cycle by lifts is wrong: most of the time the lure is either falling or still settling in place.
What the line shows you
You read the fall by the line, not by the lure: it pays out evenly while the spoon falls and stops the instant it settles. A stop earlier than expected means either the bottom or a fish, and the only way to tell them apart is by the resistance. That's why anglers pick a line for a jigging spoon with little memory, one that straightens on its own.
Why a casting spoon works differently
A casting spoon also has action on the fall, but there it's an extra on top of the retrieve, while here it's the only mode there is. That's where the difference in the body comes from: an ice spoon is narrower and heavier, because casting distance doesn't matter to it.