Three under is placing all 3 fingers under the arrow on the string with the nock above. Supposedly it puts the arrow closer under your eye for siting instead of the split finger grip. I don't see my arrow when I shoot. I try to concentrate on where the arrow will hit.
Most folks nock under the string nock. I read in a book years ago that archers then nocked over so they could shoot arrows faster by pulling the arrow from their back quiver, sliding it on the string and down on the nock for the shot then retrieved another arrow and did the same. Kind of like an archery auto-loader.
Been doing it ever since.
