Bowstrings are oscillating left-right as they approach the bow. (You can see this in high speed videos; check out YouTube, there are oodles of examples of bows and arrows shot at high speed (aka slow motion).) The arrow leaves the string when the limbs stop the string from moving forward. Where the string is in its left-right cycle (a matter of a bunch of variables but especially on how tight the nocks are) determines where it is pointed left-right, so the answer to your question is “yes.” A too tight nock will delay the point the arrow leaves the string. A test of correct nock fit is to snap an arrow onto the string and let it hang straight down (with the bow sideways). It should support its own weight. If you rotate the bow about the axis of the string, the arrow should point down the whole time. (The “ears of the nock” surround the string but do not pinch it.) Additionally, a tap on the bowstring right next to the hanging arrow should cause it to fall off.
Re Growing Archers As recurve archers grow taller, their draw lengths grow longer and their draw weights go up. All of these effects require stiffer arrows (2˝ in height = 1˝ in draw = 1˝ shorter arrow needed (or same length in the next stiffer spine group of arrow shafts). Arrows that are too weak fly right (right-handed archers), arrows that are too stiff fly left, so “nock fit” is not the only source of left or right arrows.
Archers with light drawing bows (mentioned in a previous email) experience any number of problems that go away when the draw force and bow and arrow masses go up. The tension on the bowstrings of such bows is so low that the strings can be twisted into pretzels. (I can take a Genesis bow and turn the center serving 180 degrees.) This severely affects the path the string takes as it pushes the arrow out of the bow. The arrows are so light that they move with the slightest touch (and often those small, beginner fingers are touching the arrow at full draw—one of the many reasons we avoid “split finger” grips of the string until the distances being shot climb enough to need one).
The 16 strand string is overkill and a bit fat, although 8125G is a quite skinny bowstring material. Our standard strings for our beginner classes (youths and adults) was 14, and her setup calls for a 12-strand string.
One possible fix for the nock fit problem if they are too tight, is to re-serve the center section with a higher serving pressure setting, which would make for a tighter (and therefore smaller) serving section.