The pause is the time between casting strokes, and what it must allow is for the line to straighten. When line speed changes, that time changes with it. A faster cast unrolls the line sooner, so the pause can be shorter; a slower cast needs longer. The line sets the pause, not a count in your head.

That is why distance alone is an incomplete instruction. The Fifth Essential ties the pause to the amount of line outside the rod tip, and that is a sound starting point, but two casts at the same distance can be made at different speeds. The faster one straightens sooner and needs less pause; the slower one needs more. A rule that mentions only distance misses half of the input.

Watch the line instead of counting. Start the next stroke as the line straightens: too early and it is still unrolling, too late and it has begun to fall. When you change line speed, change the pause with it, and teach the student to read the line rather than to match a number.

Source

From the mechanics discussion in the MCI Study Guide (March 2023), used here for supporting mechanics rather than CI rules; exam material is in the CI Study Guide (2025); terms follow the FFI Fly Casting Definitions.