When installing nocks on wood arrows there is
a proper way to align the nock with the grain of the arrow. Since wood has
grain, it resists bending at a different rate depending upon the orientation
of the grain to the direction of the bending. Wood arrow shafts are generally
tested for spine in their strongest grain orientation, so in order to be
consistent you should orient your nock in the same direction. The following
diagram shows the proper grain orientation for nock placement and how a
cross-section cut through an arrow on a bow shelf would appear.
In this diagram I have exaggerated the grain
"pointers" for illustration purposes. If the arrow should crack
or break along the grain line you don't want the sharp end pointing towards
your bow hand. I have never seen this happen, but why take the chance.