Changes

Usually the eight surrounding border files are divided 4:4, so the offset of the upper left square is 36. For a symmetric treatment of files and ranks, 16x16 is also quite common <ref>[http://www.open-aurec.com/wbforum/viewtopic.php?f=4&t=2407&p=11195#p11109|Re: Fruit's Board Representation?]] by [[Fabien Letouzey]], [[Computer Chess Forums|Winboard Forum]], April 28, 2005</ref> .