Coordinates trick

Hello,

If you convert the row character to its corresponding number (a=1, .. h=8), the following holds:

if (row + colum) is odd, the square is white
if (row + column is even, the square is black

So h1 = (8+1) = 9 = odd = white
And d5 = (4+5) as well

a1 = (1+1) is even, and therefore black

Works for all squares, never realised this :)

cheers, Chris

By the way, correspondence chess used to be transmitted with numbers only, a move was 4-digit on a postcard. 1. 5254 for example.

@cr2015
Playing many games and memorising all squares is more efficient (did that)