How do you determine which end of the start line is favored? It has nothing to do with where the first mark is. It is determined by the direction of the wind with respect to the starting line. If the starting line is set exactly square with the direction of the wind then there is no favored end. However, committee boats rarely set a square line and therefore one end is usually favored over the other.After running the start line to find its relative position and wind shot is taken to find the direction of the true wind. The side closer to the true wind is the favored end. If the line is long and very unsquare this can mean several boat lengths of advantage to those choosing that end. A significant advantage in a close race.