Bugcat's Tengen coordinates

bugcat: Recently I've seen a number of interesting and inventive alternative coordinate systems here on SL (eg. AudouardCoordinates, Rokirovka/Coordinates, and Coordinates/Schurig). This prompted an idea for a novel coordinate system, based not on one or even four corners, but instead on tengen.

The coordinates are set out as below. Note that the board setup is from Black's perspective, meaning that his first move would likely be at +G+6 (the top right hoshi).

-J+9  -I+9  -H+9  -G+9  -F+9  -E+9  -D+9  -C+9  -B+9  =A+9  +B+9  +C+9  +D+9  +E+9  +F+9  +G+9  +H+9  +I+9  +J+9

-J+8  -I+8  -H+8  -G+8  -F+8  -E+8  -D+8  -C+8  -B+8  =A+8  +B+8  +C+8  +D+8  +E+8  +F+8  +G+8  +H+8  +I+8  +J+8

-J+7  -I+7  -H+7  -G+7  -F+7  -E+7  -D+7  -C+7  -B+7  =A+7  +B+7  +C+7  +D+7  +E+7  +F+7  +G+7  +H+7  +I+7  +J+7

-J+6  -I+6  -H+6  -G+6  -F+6  -E+6  -D+6  -C+6  -B+6  =A+6  +B+6  +C+6  +D+6  +E+6  +F+6  +G+6  +H+6  +I+6  +J+6

-J+5  -I+5  -H+5  -G+5  -F+5  -E+5  -D+5  -C+5  -B+5  =A+5  +B+5  +C+5  +D+5  +E+5  +F+5  +G+5  +H+5  +I+5  +J+5

-J+4  -I+4  -H+4  -G+4  -F+4  -E+4  -D+4  -C+4  -B+4  =A+4  +B+4  +C+4  +D+4  +E+4  +F+4  +G+4  +H+4  +I+4  +J+4

-J+3  -I+3  -H+3  -G+3  -F+3  -E+3  -D+3  -C+3  -B+3  =A+3  +B+3  +C+3  +D+3  +E+3  +F+3  +G+3  +H+3  +I+3  +J+3

-J+2  -I+2  -H+2  -G+2  -F+2  -E+2  -D+2  -C+2  -B+2  =A+2  +B+2  +C+2  +D+2  +E+2  +F+2  +G+2  +H+2  +I+2  +J+2

-J+1  -I+1  -H+1  -G+1  -F+1  -E+1  -D+1  -C+1  -B+1  =A+1  +B+1  +C+1  +D+1  +E+1  +F+1  +G+1  +H+1  +I+1  +J+1

-J=0  -I=0  -H=0  -G=0  -F=0  -E=0  -D=0  -C=0  -B=0  =A=0  +B=0  +C=0  +D=0  +E=0  +F=0  +G=0  +H=0  +I=0  +J=0

-J-1  -I-1  -H-1  -G-1  -F-1  -E-1  -D-1  -C-1  -B-1  =A-1  +B-1  +C-1  +D-1  +E-1  +F-1  +G-1  +H-1  +I-1  +J-1

-J-2  -I-2  -H-2  -G-2  -F-2  -E-2  -D-2  -C-2  -B-2  =A-2  +B-2  +C-2  +D-2  +E-2  +F-2  +G-2  +H-2  +I-2  +J-2

-J-3  -I-3  -H-3  -G-3  -F-3  -E-3  -D-3  -C-3  -B-3  =A-3  +B-3  +C-3  +D-3  +E-3  +F-3  +G-3  +H-3  +I-3  +J-3

-J-4  -I-4  -H-4  -G-4  -F-4  -E-4  -D-4  -C-4  -B-4  =A-4  +B-4  +C-4  +D-4  +E-4  +F-4  +G-4  +H-4  +I-4  +J-4

-J-5  -I-5  -H-5  -G-5  -F-5  -E-5  -D-5  -C-5  -B-5  =A-5  +B-5  +C-5  +D-5  +E-5  +F-5  +G-5  +H-5  +I-5  +J-5

-J-6  -I-6  -H-6  -G-6  -F-6  -E-6  -D-6  -C-6  -B-6  =A-6  +B-6  +C-6  +D-6  +E-6  +F-6  +G-6  +H-6  +I-6  +J-6

-J-7  -I-7  -H-7  -G-7  -F-7  -E-7  -D-7  -C-7  -B-7  =A-7  +B-7  +C-7  +D-7  +E-7  +F-7  +G-7  +H-7  +I-7  +J-7

-J-8  -I-8  -H-8  -G-8  -F-8  -E-8  -D-8  -C-8  -B-8  =A-8  +B-8  +C-8  +D-8  +E-8  +F-8  +G-8  +H-8  +I-8  +J-8

-J-9  -I-9  -H-9  -G-9  -F-9  -E-9  -D-9  -C-9  -B-9  =A-9  +B-9  +C-9  +D-9  +E-9  +F-9  +G-9  +H-9  +I-9  +J-9

There are a few reasons why I like these coordinates, though they're just an experiment:

• No point is more than 8 intersections away from the start point, compared with 18 in a single-corner system.

• There are only two axes, compared with eight in a four corner system.

• They're based on tengen, the only unique point on the board.

Example kifu: Takao Shinji vs Yamashita Keigo, 2000

Moves 1–10  

01–02: +F+5 =A=0
03–04: –F–5 –G+6
05–06: +G–6 –H–6
07–08: –H+4 –F–6
09–10: =A–1 –B–1

Moves 11–20  

11–12: –B=0 =A+1
13-14: +B–1 –B–2
15-16: –C=0 –E–5
17-18: –C+2 +C+1
19-20: =A–3 +C=0