I have a single pin, Impact Solo. It' s set at 22 yards because I never shoot past 30, and this setting puts me approx. halfway between the drop from 10 yards to 30.

By the way, this is the drop between 20 and 40, depending on speed.

Speed (fps) Drop in inches
220........... 28.7
240........... 24.2
260........... 20.6
280........... 17.7
300........... 15.5
320........... 13.6

The drop is greater from 20 yards to 30 yards, than from 10 yards to 20 yards, because the arrow is constantly losing speed. At 280 fps, the drop from 20 to 30 yards should be in the neighborhood of 8" . From 25 to 30, somewhere in the 5" range. This will vary slightly depending on the drag on the arrow. Large fletching and feathers will slow the arrow quicker, causing a slightly greater drop.