Just to expand a bit, my gaps are about as follows, measured at the target:
10 yards, 1’ under
20 yards, 2’ under
30 yards, 1’ under
40 yards, 6” under
44 yards, point on
50 yards, 2’ over
I'm using round numbers just to give you the idea of how gaps work. As the arrow arcs up, initially it gets higher and higher over the point you want to hit, and hits its highest point when it is halfway to your point on distance, so that is your maximum negative gap. As you go beyond the point on distance, you need to hold your aim higher and higher the further away you are, because the arrow is falling at an increasing rate as it loses momentum.