John Lawson wrote on Sat, Feb 26, 2011 04:59 AM UTC:
There is either a post or a comment in an article somewhere on this site
where Ralph admits that he mostly designs variants on 64-square boards
because, as a US-Master-level FIDE chess player, that was the board he
could most easily visualize. This allowed him to do his play-testing in his
head, without resorting to physical equipment.