I' m with PW12 on this one. Having seen and documented the varying forms of nock travel over the years, and I mean VARYING, I can' t see how putting the loop under the arrow could really be advantageous. I' ve really only seen this procedure done by some tournament archers and those who emulate them. There are probably many others, but I haven' t seen them.

While putting two tied-in nocks above and below the arrow is good, we do it differently. We make sure we have extra large ' beads' at each end of the loop. When tightening the loop we use about 100+ pounds of pressure while controlling the width of the loop to fit the arrow' s nock. With this method, we keep the loop exceptionally tight so that it will not move or break loose. The only problem you may have with any loop is the serving moving and opening up the loop; but, this can happen with other forms of arrow captivation as well.