Checkers notation: how squares and moves are written

Checkers players have recorded games with a simple numbering system for well over a century. Once you know it you can read the move list beside our board, follow games in books, and set up any position from a line of text.

The 32 numbered squares

Only the dark squares are used in checkers, so only they get numbers, 1 to 32. Numbering starts on the side that moves first. In books that is Black; on this site it is Red. Square 1 is at the right-hand end of Red's back row, as Red sees it, and the numbers run across the board row by row, four to a row, so Red's three starting rows hold squares 1 to 12 and White's hold 21 to 32.

The numbers belong to the board, not to the player. Squares 1 to 4 are always Red's back row and the row White must reach to crown a piece; 29 to 32 are White's back row and Red's crowning row. When you play White here, the board turns around and square 1 appears at the top, but it is still the same square.

The small numbers in the corner of each dark square on our game board show this system, so you never have to count.

Corners worth knowing

Two corners of the board hold a single dark square each: 4, in the corner at Red's left hand, and 29 at White's left. The other two corners each have a pair of dark squares next to each other: 1 and 5 on Red's side, and 28 and 32 on White's. These are the double corners, and they matter in the endgame, because a lone king that reaches one can shuttle between the two squares and is much harder to trap. The long diagonal from 4 to 29, crossing the whole board, is often simply called the long diagonal.

Writing a move

A move is written as the square a piece starts on and the square where it finishes:

• 11-15: the piece on 11 moves to 15. A hyphen means an ordinary move.
• 15x22: the piece on 15 jumps to 22, capturing the piece in between (on 18 here). An x means a capture.
• 6x15x24: a double jump, listing every square the piece lands on.

The captured pieces are never written down, because they are always the ones between the squares. Many books shorten a multiple jump to its start and end, such as 6x24; our move list always writes every landing square, which removes any doubt when two routes are possible.

Reading a game

Moves are listed in pairs, the first player's move and then the reply, numbered in order. Here is the start of one of the most common openings:

1. 11-15 23-19
2. 8-11 22-17

Red begins by moving the piece on 11 to the center at 15, and White answers 23-19, facing it. Red then brings 8 up to the square just vacated, and White moves 22-17. If you set up the starting position and play those four moves, you reach this position:

Our move list works the same way, with Red's move on the left and White's on the right. If a game starts from a set position with White to move, the first Red space shows "…".

Writing down a whole position

To describe a position without a diagram, list the pieces of each side by square, marking kings with a K, and say who is to move. The format used by checkers software (the "FEN" tag of Portable Draughts Notation) looks like this:

W:W18,K27:B11,15

That means White to move, White pieces on 18 and a king on 27, and Black pieces on 11 and 15. This site uses the same format with R for Red instead of B for Black, so the position above would be W:R11,15:W18,K27.

You can open any position in the game by adding it to the address of the home page as ?fen=. For example, this link starts a game from R:R11,15:W18,K27, Red to move, against the computer. Everything the puzzles and strategy pages call Play this position works this way.

A quick exercise

Using the numbered diagram above, try to answer these without looking back:

1. Which two squares can a Red piece on 9 move to?
2. A White piece on 23 moves forward. Where can it go?
3. Red's piece on 14 jumps a White piece on 18. Where does it land?

Next: put the numbers to work with the openings guide, or play a game and watch the move list.