I sat down to draft the left side of a split yoke. I started with an 11" x 17" sheet of paper. On this sheet I drew a box roughly 9.25" (my shoulder measurement divided by 2) x 4" (a generous estimate of the height of the finished yoke). On the lower part of the right side of the box(the place where the halves of the yoke are joined) I marked off a 1.375" line, knowing that this was the height of the midpoint of the yoke that best fit me. The slight bend in the top line running across the shoulder is there so that the sides of the yoke can match the angle of my shoulders, while the upper/middle portion of the yoke can (hopefully) follow my trapezius muscle and "hug" my upper back. I measured the distance from my shoulder to the base of my neck, which was a little over 6 inches. I drew this line connecting the armhole side to the neckline at what I thought to be my shoulder angle, and the last part of this line I drew at a slightly steeper angle to make the transition from my shoulder to my traperius muscle, which is slightly more elevated than my shoulders. I knew that the 9-plus inch length along the bottom of the yoke couldn't just be a straight line. Rather, it should be a curve extending from the outer seam to the middle, with the middle being elevated relative to the outside in order to closely fit the middle of the back.