Does anyone know origin of smaller go boards (9*9,13*13)? When (and where) was first introduced? I looked on Sensei library but didn't find anything about history of go boards.
I was surprised when I saw a running game chance (1d) vs wangyue (2d): https://www.gokgs.com/gameArchives.jsp?user=chance wangyue had handicap 9 stones, but why? There is only one class difference! ...