At position 1 “a” and “b” are sailing in “wind 1” and are equal because they are on the same ladder rung. Just after position 1, both boats experience a slight header (left hand shift) shown as “wind 2”. Note that this causes the ladder rung to shift to stay square to the wind. After traveling the same distance “a” is now on a higher ladder rung and slightly ahead of “b”. If both boats are going the same speed they will end up at position 2. FUNDAMENTAL: In a header it pays to be the leeward most boat.