Draughts notation: square numbers, a1 to h8, FEN and PDN

How moves are written in American, Brazilian, International and Russian draughts, how to read a multiple capture, and what FEN and PDN hold.

Every move list on this site is written in the notation of its rule set, and the board labels its squares the same way. So 31x22x13 in American checkers and e1xa5 in Brazilian draughts can be the same double capture, as the boards below show.

Two ways to name a square

Only the dark squares are ever used, so only they get names.

American and International number them: squares 1 to 32 on the 8×8 board, squares 1 to 50 on the 10×10 board. The count starts on Black's back row, at the top of the board as White sees it, and runs left to right, row by row. White starts on the high numbers and moves towards the low ones.

Brazilian and Russian use a letter and a number. Files run a to h from White's left, ranks 1 to 8 from White's side. It is the same 8×8 board with other names: square 29 is a1, square 32 is g1, square 1 is b8 and square 4 is h8. If your board shows no labels, switch on Coordinates in board settings.

Moves and captures

A quiet move joins its start and end with a dash. A capture joins them with an x, except in Russian draughts, which uses a colon. The rule sets part ways on the multiple capture. American checkers writes every landing square. The other three write only where the piece started and where it stopped.

American checkers, White to move: 26-23 is a quiet move, 19x26 is Black's single capture, and 31x22x13 lists both landing squares of a double capture, 22 and 13.

The same squares in Brazilian draughts, with the same moves: d2-e3, then f4xd2, then e1xa5, which names only the start and the end of the double capture.

Russian draughts writes those two captures with a colon in place of the x, and nothing else changes. International draughts combines the habits: numbers like American, start and end only like Brazilian.

International draughts on the 10×10 board, White to move: 33-28 gives up a man, 22x33 takes it, and 38x20 takes two men with no square written between 38 and 20.

There is one exception. If two legal captures share a start and an end but take different pieces, the landing squares are written as well, so the record can only mean one move.

FEN: one position on one line

FEN records a position and nothing about how it arose. W:W26,28,31:B17,19,20 is the position in the first two diagrams. The first letter says who is to move, here White, then come White's squares and Black's squares. A K marks a king, so W:WK18:B1 is a white king on 18 against a black man on 1. This site writes FEN with numbers in every rule set, Brazilian and Russian included. The line does not say which rules apply, so you choose them on the screen first.

PDN: a whole game in a text file

PDN records a game: a few tags in square brackets, such as [White "name"] and [GameType "21"], then the numbered moves in the rule set's notation. A game that did not begin from the initial position also has a FEN tag. GameType names the rules: 20 is International, 21 American, 25 Russian and 26 Brazilian.

One trap is the result tag. It counts from the side that moves first, so in American checkers, where Black starts, a score of one to nil is a win for Black. International scores a win as two points to nil.

Using them on this site

To save a game, press Download PDN on a finished game's page, or at the end of a game played on your device.
To study a game, open the analysis board, choose PDN as the starting position, paste one game and press Load position. A GameType tag sets the rules; without one, the rules you selected apply. A finished game's page also has an Analyse button that opens the game there directly.
To set up a position, choose FEN on the same screen, paste the line and press Load position. Under the board, the current position is always written out as FEN, so you can copy it.
A game still in progress does not open there: the screen answers that analysis is available only after it finishes.

The reader behind that screen is forgiving. It accepts numbers or letters in any rule set, and an x, a colon or a dash between squares, and it skips comments and side variations.

The glossary covers the rest of the vocabulary, and forcing captures puts these moves to work.