Difficulty in measuring! in Marblehead Posted 16 hours ago Your method sounds right but it is easy to check if you have got them right. The straight line distances from the half height point to the head and clew should be the same similarly the distances between the 1/4 point and the head and 1/2 point. Ditto 3/4 point and 1/2 height / clew. The 1992 version of the rules had a useful diagram.