A picture (diagram) is worth a thousand words:
a11 a21 a31 a41 a51 a61 a71 a81 a91 a1 b91 b81 b71 b61 b51 b41 b31 b21 b11
a12 a22 a32 a42 a52 a62 a72 a82 a92 a2 b92 b82 b72 b62 b52 b42 b32 b22 b12
a13 a23 a33 a43 a53 a63 a73 a83 a93 a3 b93 b83 b73 b63 b53 b43 b33 b23 b13
a14 a24 a34 a44 a54 a64 a74 a84 a94 a4 b94 b84 b74 b64 b54 b44 b34 b24 b14
a15 a25 a35 a45 a55 a65 a75 a85 a95 a5 b95 b85 b75 b65 b55 b45 b35 b25 b15
a16 a26 a36 a46 a56 a66 a76 a86 a96 a6 b96 b86 b76 b66 b56 b46 b36 b26 b16
a17 a27 a37 a47 a57 a67 a77 a87 a97 a7 b97 b87 b77 b67 b57 b47 b37 b27 b17
a18 a28 a38 a48 a58 a68 a78 a88 a98 a8 b98 b88 b78 b68 b58 b48 b38 b28 b18
a19 a29 a39 a49 a59 a69 a79 a89 a99 a9 b99 b89 b79 b69 b59 b49 b39 b29 b19
d1 d2 d3 d4 d5 d6 d7 d8 d9 10 b9 b8 b7 b6 b5 b4 b3 b2 b1
d19 d29 d39 d49 d59 d69 d79 d89 d99 c9 c99 c89 c79 c69 c59 c49 c39 c29 c19
d18 d28 d38 d48 d58 d68 d78 d88 d98 c8 c98 c88 c78 c68 c58 c48 c38 c28 c18
d17 d27 d37 d47 d57 d67 d77 d87 d97 c7 c97 c87 c77 c67 c57 c47 c37 c27 c17
d16 d26 d36 d46 d56 d66 d76 d86 d96 c6 c96 c86 c76 c66 c56 c46 c36 c26 c16
d15 d25 d35 d45 d55 d65 d75 d85 d95 c5 c95 c85 c75 c65 c55 c45 c35 c25 c15
d14 d24 d34 d44 d54 d64 d74 d84 d94 c4 c94 c84 c74 c64 c54 c44 c34 c24 c14
d13 d23 d33 d43 d53 d63 d73 d83 d93 c3 c93 c83 c73 c63 c53 c43 c33 c23 c13
d12 d22 d32 d42 d52 d62 d72 d82 d92 c2 c92 c82 c72 c62 c52 c42 c32 c22 c12
d11 d21 d31 d41 d51 d61 d71 d81 d91 c1 c91 c81 c71 c61 c51 c41 c31 c21 c11
Pierre Audouard has severe visual impairment ( Retinitis pigmentosa). He can just about see a go board adequately for playing if a strong light is shone on the board. However he cannot follow a game from a printed paper. He invented these coordinates in order to be able to replay pro and amateur games on a board. He now uses special audio software that reads out the moves from a sgf file using this coordinate system. He finds it much easier to mentally visualise the board using these coordinates than with the standard coordinates. Standard coordinates are not natural for a go player, who is used to referring to points according to their distance from the corner. This system is much closer to that way of reasoning. For the same reason, Audouard coordinates are better for blindfold go than usual coordinates.
John F. Although Pierre Audoard sounds like a truly remarkable person, and he may well have devised this system independently, I think it needs to be recorded that it appears to be identical to the ancient Chinese system first seen in Carefree & Innocent Pastime. But that raises an interesting question about motivation, along the lines of great minds think alike, perhaps. It also means that lots of problems and game commentaries using this system already exist in the old Chinese literature. Personally I found it a bit of a curate's egg, but it strikes me as usable and I wouldn't take too much convincing that it's a better system than the usual x,y coordinates.
ikktomuseyokkis I think he definitely did invent it himself. The reason why is that I once invented nearly the exact same system. (!) It's pretty logical to me. My version of it came about after I did a lot of thinking about the shape of the go board.
Dan The thing I like about it is that the coordinates have some semantic meaning instead of being abstract designators. 'b53' (upper right, 5-3 point) means something to me that 'P17' does not, although perhaps if I spent more time typing out go moves, coordinates such as P17 would become more meaningful to me, in the way that chess coordinates such as 'f7' (the weak spot for attacking Black's uncastled king) and 'g7' (where Black fianchettos his dark-squared bishop) have real meaning for me.
Pierre It could be used for diagrams. For exemple a very easy life and death problem
- black stones in 12-22-32-42-41
- white stones in 13-23-33-43-53-52-51
- or we can use for joseki
- an easy joseki 44-36-63-24-33-39 or 44-63-36-42-33-93
- white stones in 13-23-33-43-53-52-51
rokirovka I personally prefer a different coordinate system: the points in the bottom left corner are the usual A1, B1, C1..., A2, B2, C2..., A3, B3, C3... and so on for A-K and 1-10. But rather than the cumbersome letters L-T and numbers 11-19, the other three corners use the same letters and numbers, only marked by asterisks:
The bottom right corner is A*1, B*1, C*1..., A*2, B*2, C*2..., A*3, B*3, C*3...
The top left corner is A1*, B1*, C1*..., A2*, B2*, C2*..., A3*, B3*, C3*...
The top right corner is A*1*, B*1*, C*1*..., A*2*, B*2*, C*2*..., A*3*, B*3*, C*3*...
I discuss this system further on the Coordinates page: Coordinates.
The reason I prefer this system over the Audouard system is that I can more easily follow a series of moves in one corner when the moves are distinguished by a letter and a number rather than by two numbers. For my brain at least, I can distinguish Black C*4* White E*3* Black G*3* White E*5* Black D*6* White H*4* more clearly than Black b34 White b53 Black b73 White b55 Black b46 White b84 or 34-53-73-55-46-84.
As an example, here are Pierre's life and death problem and joseki above translated into my coordinate system.
life and death problem:
Black A2, B2, C2, D2, D1
White A3, B3, C3, D3, E3, E2, E1
I can read off these coordinates, picture them in my head, and instantly say to myself, "Whoever has the move plays at B1." It would take me longer to read the Audouard coordinates, picture them in my head, and see that the answer is 21.
1.D4 C6 2.F3 B4 3.C3 C9 or 1.D4 F3 2.C6 D2 3.C3 J3
tapir: I believe 34 - 43 may look too similar and difficult to remember at first sight only. But in baduk they really are similar. Actually, they are the same (as first move) but for symmetry! I've even seen very strong players, while reconstructing a whole game flawlessly -> but starting with different orientation. That is - if you start seeing the sequences and natural moves it may be very unlikely that you switch first and second number while recording consecutive moves, but you see instantly 94 and 49 is the 4th line stone next to the star point. Even more those coordinates are quite often used in one quadrant already (e.g. joseki pages on SL) and A. just adopted them for the whole board. And try to imagine someone blind is reading the coordinates! Which coordinate system will be more convenient.
ikktomuseyokkis: one game per line, here are the complete games of shusaku in audouard coordinates: https://gist.github.com/1417181 along with a script for reading them out using festival text to speech on unix-like systems https://gist.github.com/1417066 -- of course, with one game per line, you need to use the split command (eg split -dl 1 -a 3 hypostasizedghostofshusaku completegames/0) and it's also preferable to do some finding and replacing or scripting to make each game have one move per line and a space between quadrant name and intersection number. i have written another script to convert sgf to audouard coordinates but i am not done with it yet. when i am i will put it in the same location on github.
Multifolio: Thank you very much for the list of Shusaku games. It has a small mistake in the game 429.
I want convert a "sgf" file in a secuence of coordinates Audouard.