Agree with Arrowmaker, if the arrow is spined correctly, it should fly correctly regardless of cant. However, the distance between your bow hand and the arrow and the amount of centershot of the bow can muck things up. If there's a fairly substantial distance between the top of your bow hand and the top of the arrow shelf, canting the bow to the right, will, in fact, move the arrow to the right, which will generally cause it to shoot right. Your brain may or may not adjust for it. Longbows, which usually aren't cut to center, require much more precise arrow matching, but if the arrow is properly spined to the bow, the arrow should shoot where you look. However, often, the shooter isn't looking where the arrow is pointing with a vertically held bow. Canting the bow brings the arrow directly under the eye, provided the bow hand is very close to the arrow, (see above) and helps to control left right shooting.