It is my understanding that the seam on the ball is where the two hemispheres that are used to make the cover are joined together. Some balls have a seam and some are seamless. On Titleist balls, the seam is located where the ball type is printed ex. Pro v1 392, while the name Titleist is printed at the center of each of the hemispheres. Seaming the Pro v1 involves hitting the ball directly on the seam ex. teeing up the ball so that the word Titleist is facing the golfer and the the words Pro v1 392 is pointing towards the target. This supposedly gives a more boring trajectory and adds a few yards. Hope that helps.