Comment on Bowling Tip 23 – Use four points of reference by York W. Porter.

Sorry to bother you. I am a long time bowler who has a question about the Brunswick Rangefinder System. I have searched the Internet/looked in various bowling books without success in trying to find the answer.
First, I know that the arrows and the dots on the approach all line up with the visible pins that are facing the bowler, i.e, the 1,2,3,4,6,7,10 pins. The dots just about six/seven feet out from the foul line towards the arrows are *not* so aligned, as you point out.. Can you enlighten me as to why these dots are *not* aligned like the rest since I’m sure there was *some* sort of reasoning on putting these dots “offset” from the rest. Also, of course, I am trying to figure out how they figured in to the Rangefinder system as it was originally developed in WWII. I wasn’t quite sure I understood the “Play with determining which board is half way between your mark and your target and aim at that board’s dot”. Thanks for any help you can be.
Again, sorry to bother you but I haven’t found the answer elsewhere. Most references, including the tips from Bob Strickland on the web, mention the dots on the lane and then seem to ignore them. Of course, it may be that I’m just not understanding things well.