Article Index


The traditional coordinate system
  1  2  3  4  5
6  7  8  9  10 
  11  12  13  14  15
16  17  18  19  20 
  21  22  23  24  25
26  27  28  29  30 
  31  32  33  34  35
36  37  38  39  40 
  41  42  43  44  45
46  47  48  49  50 
I've played Draughts ever since I was a kid, but I've never liked its traditional notation system, in which the squares are numbered 1 to 50 as in the table depicted here.
After I invented Bushka the need for a better coordinate system arose. On the above 10x10 board one can fairly easily count the subsequent squares of a column - say 3-13-23-33-43 - but Bushka was at the time played on a 9x11 board and one would have to count 3-14-25-36-47. Similar 'uneasy' counts appear in 8x8 Draughts variants (3-11-19-27) and in the 12x12 canadian variant (3-15-27-39-51-63).
One can easily understand why players of 64 variants tend to fall back on Chess notation!

diagonal_coordinatesPondering the problem I focused on the fact that the diagonal subdomain of a square board is in fact a square tesselation itself, albeit 45 degrees rotated.
This is picture one gets if one rotates a draughts board 45 degrees counterclockwise and applies a transparent square overlay.
The coordinate system for the overlay is both usual and logical.
So why not hang on to it when the board is rotated back, as in the table below!

The diagonal coordinate system
  a6  b7  c8  d9  e0
a5  b6  c7  d8  e9 
  b5  c6  d7  e8  f9
b4  c5  d6  e7  f8 
  c4  d5  e6  f7  g8
c3  d4  e5  f6  g7 
  d3  e4  f5  g6  h7
d2  e3  f4  g5  h6 
  e2  f3  g4  h5  i6
e1  f2  g3  h4  i5 
The resulting notation system is easy to learn, concise and equally well applicable for every board size, even for a rectangular board like Bushka had in the early days!
It has excellent features. A non capturing move always keeps a particular line. The index change on that line is sufficient to indicate the move.
Thus f45 and gf5 indicate moves of a white man or any king. This makes the system even more concise than Chess notation!

A multiple piece-capture does not necessarily keep a particular line and may end on the square of origin. The 'x' sign comes behind the indices, for instance e8g6x, eg8x or f6x.
Putting the 'x' sign at the end gives it a fixed place. Otherwise it would appear left or right in for instance fxd4 and f4x6.

Later I read in J.F. Moser's Pocket Encyclopedia for Draughts players that it has been suggested before by Canadian Draughts player Paul Sonier in 1925.

As can be seen throughout the Draughts section, another feature of the diagonal notation system is that the oblique lines can be indicated on the side of the board very much the same way ranks and files are indicated on a Chess board.

When you play in the ArenA, moves may be entered either way.