Coordinates

  Difficulty: Introductory   Keywords: Opening

Coordinates are used to name every point on the go board, e. g. in a game record or simply to describe stones on the board. Several styles are in use.

Table of contents

Style A1

In Europe it is usual to give coordinates in the form of A1 to T19. Where A1 is in the lower left corner and T19 in the upper right corner (from black's view).

Note: "I" is not used, historically to avoid confusion with "J"

Style 1-1 or 一1

There are also other coordinate notations in use, e.g. in the form of two figures 1-1 to 19-19. In (Japanese) writing one of the two coordinates usually is given in kanji.

Note that 1-1 is at the upper left corner and 19-19 at the lower right corner. For an example see this game record:
http://www.asahi.com/igo/photogallery/image/TKY200609210129.jpg

Named points

In literature and here on Sensei's Library, points are named by their position with respect to the nearest corner. Symmetrical points collapse. This means there are four 3-3 points and 8 3-4 points. Named points are used for isolated corner analysis. See Named Points.

Audouard coordinates

See Audouard coordinates for a different coordinate system more suited to Go.

Conversion table

Just in case you were having trouble memorizing coordinate equivalents by point name.

Western Point Inversion Chart for 19x19 Goban:

 1 = 19 = A = T
 2 = 18 = B = S
 3 = 17 = C = R
 4 = 16 = D = Q
 5 = 15 = E = P
 6 = 14 = F = O
 7 = 13 = G = N
 8 = 12 = H = M
 9 = 11 = J = L
 10 = 10 = K = K
 11 = 9 = L = J
 12 = 8 = M = H
 13 = 7 = N = G
 14 = 6 = O = F
 15 = 5 = P = E
 16 = 4 = Q = D
 17 = 3 = R = C
 18 = 2 = S = B
 19 = 1 = T = A

See also


% axd: what to do with following - it's basically using base-19 to express coordinates in a (x,y) system - in an elaborate way. how about throwing it away or reduce it to its essence?

(cut from Rokirovka/Coordinates because not really related - plus, not related to homepage)

Daniel?: I have been thinking about it and I have a suggestion that in part comes from my experience as a programmer I call the system B19 (a contraction of Base 19) now this takes a bit of a different tack as to where the initial index is (the programming experience coming in) and this may not be to the liking of some but where for other systems the initial index is 1 or A the initial index in this system 0 (which some players may not like) and has a maximum index on I with the format being (y,x) or yx (which works since every column ans row is represented by a single digit) so what some would cal the 1,1 point in this system would be the 0,0 or 00 or 0 point now what is that about you ask? well from this column row system there arises a natural numbering system where you can also call a point by a single number rather than as a pair of numbers with point 0,0 being point 0 and II (aka 18,18 or in a traditional system 19,19) also being called point 360. to summarize base 19:
0=0
1=1
2=2
3=3
4=4
5=5
6=6
7=7
8=8
9=9
A=10
B=11
C=12
D=13
E=14
F=15
G=16
H=17
I=18
unfortunately while this is fairly intuitive for anyone who is well enough versed in computer programming or certain areas of mathematics it may cause problems for the average player.

 0,0  0,1  0,2  0,3  0,4  0,5  0,6  0,7  0,8  0,9  0,A  0,B  0,C  0,D  0,E  0,F  0,G  0,H  0,I
1,0 1,1 1,2 1,3 1,4 1,5 1,6 1,7 1,8 1,9 1,A 1,B 1,C 1,D 1,E 1,F 1,G 1,H 1,I
2,0 2,1 2,2 2,3 2,4 2,5 2,6 2,7 2,8 2,9 2,A 2,B 2,C 2,D 2,E 2,F 2,G 2,H 2,I
3,0 3,1 3,2 3,3 3,4 3,5 3,6 3,7 3,8 3,9 3,A 3,B 3,C 3,D 3,E 3,F 3,G 3,H 3,I
4,0 4,1 4,2 4,3 4,4 4,5 4,6 4,7 4,8 4,9 4,A 4,B 4,C 4,D 4,E 4,F 4,G 4,H 4,I
5,0 5,1 5,2 5,3 5,4 5,5 5,6 5,7 5,8 5,9 5,A 5,B 5,C 5,D 5,E 5,F 5,G 5,H 5,I
6,0 6,1 6,2 6,3 6,4 6,5 6,6 6,7 6,8 6,9 6,A 6,B 6,C 6,D 6,E 6,F 6,G 6,H 6,I
7,0 7,1 7,2 7,3 7,4 7,5 7,6 7,7 7,8 7,9 7,A 7,B 7,C 7,D 7,E 7,F 7,G 7,H 7,I
8,0 8,1 8,2 8,3 8,4 8,5 8,6 8,7 8,8 8,9 8,A 8,B 8,C 8,D 8,E 8,F 8,G 8,H 8,I
9,0 9,1 9,2 9,3 9,4 9,5 9,6 9,7 9,8 9,9 9,A 9,B 9,C 9,D 9,E 9,F 9,G 9,H 9,I
A,0 A,1 A,2 A,3 A,4 A,5 A,6 A,7 A,8 A,9 A,A A,B A,C A,D A,E A,F A,G A,H A,I
B,0 B,1 B,2 B,3 B,4 B,5 B,6 B,7 B,8 B,9 B,A B,B B,C B,D B,E B,F B,G B,H B,I
C,0 C,1 C,2 C,3 C,4 C,5 C,6 C,7 C,8 C,9 C,A C,B C,C C,D C,E C,F C,G C,H C,I
D,0 D,1 D,2 D,3 D,4 D,5 D,6 D,7 D,8 D,9 D,A D,B D,C D,D D,E D,F D,G D,H D,I
E,0 E,1 E,2 E,3 E,4 E,5 E,6 E,7 E,8 E,9 E,A E,B E,C E,D E,E E,F E,G E,H E,I
F,0 F,1 F,2 F,3 F,4 F,5 F,6 F,7 F,8 F,9 F,A F,B F,C F,D F,E F,F F,G F,H F,I
G,0 G,1 G,2 G,3 G,4 G,5 G,6 G,7 G,8 G,9 G,A G,B G,C G,D G,E G,F G,G G,H G,I
H,0 H,1 H,2 H,3 H,4 H,5 H,6 H,7 H,8 H,9 H,A H,B H,C H,D H,E H,F H,G H,H H,I
I,0 I,1 I,2 I,3 I,4 I,5 I,6 I,7 I,8 I,9 I,A I,B I,C I,D I,E I,F I,G I,H I,I

This is a copy of the living page "Coordinates" at Sensei's Library.
(OC) 2016 the Authors, published under the OpenContent License V1.0.
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