Comment on Bowling Tip 23 – Use four points of reference by Carl Porter.
If you draw a straight line through the center of the foul line dot to the dots 7 feet down lane 20-14, 15-11, 10-8, 5-5 and from the inner edge of the 1 board to the center of the 3 dot the lines converge at a spot roughly 18′ 10″ down the lane on the 5 board. Once you cross over the center it doesn’t line up any more. Also a right hand bowler with a 6″ gap between left foot and ball line (at the foul line) would be lined up with his left foot roughly on the 1 board on the left side if using the 20-14 line at lining up at the end of the approach.
As a guess as to why. Block oiling usually thins or stops around the 3-5 board and around the 40′ mark. The ball, depending on rotation, would roll out to this area, ride the edge of the oil to the end of the carryover and hook in.