Board in Equation:
we know chessboard is in 2D kartesian system. sothere are geometrical relations are available there.
Lets express the Vertical, Horizontal and Diagonal lines.
Vertical lines:
a1 to a8 = (1,1) to (1,8) : X=1
b1 to b8 = (2,1) to (2,8): X=2
c1 to c8 = (3,1) to (3,8) : X=3
d1 to d8 = (4,1) to (4,8) : X=4
e1 to e8 = (5,1) to (5,8) : X=5
f1 to f8 = (6,1) to (6,8) :X=6
g1 to g8 = (7,1) to (7,8) :X=7
h1 to h8 = (8,1) to (8,8) :X=8
Horizontal lines:
a1 to h1: Y=1
a2 to h2: Y=2
a3 to h3: Y=3
a4 to h4: Y=4
a5 to h5: Y=5
a6 to h6: Y=6
a7 to h7: Y=7
a8 to h8: Y=8
Diagonals:
positively sloped:
g1 to h2: X-Y=6
f1 to h3: X-Y=5
e1 to h4: X-Y=4
d1 to h5: X-Y=3
c1 to h6: X-Y=2
b1 to h7: X-Y=1
a1 to h8: X-Y=0
a2 to g8: X-Y=-1
a3 to f8: X-Y=-2
a4 to e8: X-Y=-3
a5 to d8: X-Y=-4
a6 to c8: X-Y=-5
a7 to b8: X-Y=-6
Negatively Sloped:
b1 to a2: X+Y=3
c1 to a3: X+Y=4
d1 to a4: X+Y=5
e1 to a5: X+Y=6
f1 to a6: X+Y=7
g1 to a7: X+Y=8
h1 to a8: X+Y=9
h2 to b8: X+Y=10
h3 to c8: X+Y=11
h4 to d8: X+Y=12
h5 to e8: X+Y=13
h6 to f8: X+Y=14
h7 to g8: X+Y=15

There are deep relation between chess and math. But unfortunately we do less works on it. There are several pure research which are not publicly available. We common people can help each other to share such kind of knowledge.
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