Laws of Chess - the notation

the PGN-notation

1.
PGN is "Portable Game Notation", a standard designed for the representation of chess game. PGN is structured for easy reading and writing by human users and for easy parsing and generation by computer programs. The intent of the definition and propagation of PGN is to facilitate the sharing of public domain chess game data among chessplayers (both organic and otherwise), publishers, and computer chess researchers.

A PGN game is composed of two sections. The first is the tag pair section and the second is the movetext section. The tag pair section provides information that identifies the game by defining the values associated with a set of standard parameters. The movetext section gives the usually enumerated and possibly annotated moves of the game along with the concluding game termination marker.

The myChess.de - tag pair section:

2.
Each move except a pawn-move begins with the single upper case first letter of the moved piece:

K = King	Q = Queen	R = Rook
B = Bishop	N = Knight	= Pawn

3.
The letter code for a pawn is not used.
Example for a pawn-move to field e5: "e5"

4.
The first character of a square identifier is the file of the square. A file is a column of eight squares designated by a single lower case letter from "a" (leftmost or queenside) up to and including "h" (rightmost or kingside)

5.
The second character of a square identifier is the rank of the square; a rank is a row of eight squares designated by a single digit from "1" (bottom side [White´s first rank]) up to and including "8" (top side [Black´s first rank]).

6.
A square identifier contains
a) the file of the square: "a", "b", "c", "d", "e", "f", "g" or "h".
b) the rank of the square: a digit between 1 and 8.

7.
A basic move is given by
a) listing the moving piece letter (omitted for pawns) followed by
b) the destination square

In the case of ambiguities (multiple pieces of the same type moving to the same square), the first appropriate disambiguating step of the three following steps is taken:

1. If the moving pieces can be distinguished by their originating files, the originating file letter of the moving piece is inserted immediately after the moving piece letter.
    
2. (when the first step fails), if the moving pieces can be distinguished by their originating ranks, the originating rank digit of the moving piece is inserted immediately after the moving piece letter.
    
3. (when both the first and the second steps fail), the two character square coordinate of the originating square of the moving piece is inserted immediately after the moving piece letter.

• Note that the above disambiguation is needed only to distinguish among moves of the same piece type to the same square. It is not used to distinguish among attacks of the same piece type to the same square.

Capture moves are denoted by the lower case letter "x" immediately prior to the destination square.
For Example: Bxf6, Rxd1

The letter code for a pawn is not used in PGN movetext.
For example: e6, d3

Pawn captures the file letter of the originating square of the capturing pawn immediately prior to the "x" character.

En passant captures do not have any special notation. They are formed as if the captured pawn were on the capturing pawn´s destination square.

8.
Pawn promotions are denoted by the equal sign "=" immediately following the destination square with a promoted piece letter (indicating one of knight, bishop, rook, or queen) immediately following the equal sign.
For example: e8=Q, dxe1=N

9.
O-O = kingside castling

O-O-O = queenside castling

x = capture move

+ = checking move

# = checkmating move

10.
The result of the game concludes the movetext:
White wins: 1-0
Black wins: 0-1
drawn game: 1/2-1/2
game still in progress: *

the FEN-notation

FEN is "Forsyth-Edwards Notation". It is a standard for describing chess positions. For example:
rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq e3 0 1

FEN is based on a 19th century standard for position recording designed by the Scotsman David Forsyth, a newspaper journalist. The original Forsyth standard has been slightly extended for use with chess software by Steven Edwards with assistance from commentators on the Internet.

The FEN-description of a chess-position contains 6 different fields. Each field is separated from each other by a whitespace:

FEN specifies the

1. placement of the pieces on the board
   
2. active color
   
3. the castling availability
   
4. the en passant target square
   
5. the halfmove clock
   
6. the fullmove number

1. placement of the pieces on the board
The first field represents the placement of the pieces on the board. The board contents are specified starting with the eighth rank and ending with the first rank. For each rank, the squares are specified from file a to file h.

White pieces are identified by uppercase piece letters ("PNBRQK") and black pieces are identified by lowercase piece letters ("pnbrqk").

Empty squares are represented by the digits one through eight. The digit used represents the count of contiguous empty squares along a rank. A solidus character "/" is used to separate data of adjacent ranks.

The starting position has the following FEN-notation:

rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1

2. active color
The second field represents the active color.
A lower case "w" is used if White is to move.
A lower case "b" is used if Black is the active player.

3. the castling availability
The third field represents castling availability. This indicates potential future castling that may or may not be possible at the moment due to blocking pieces or enemy attacks. If there is no castling availability for either side, the single character symbol "-" is used. Otherwise, a combination of from one to four characters are present. If White has kingside castling availability, the uppercase letter "K" appears. If White has queenside castling availability, the uppercase letter "Q" appears. If Black has kingside castling availability, the lowercase letter "k" appears. If Black has queenside castling availability, then the lowercase letter "q" appears. Those letters which appear will be ordered first uppercase before lowercase and second kingside before queenside. There is no white space between the letters.

4. the en passant target square
The fourth field is the en passant target square. If there is no en passant target square then the single character symbol "-" appears. If there is an en passant target square then is represented by a lowercase file character immediately followed by a rank digit. Obviously, the rank digit will be "3" following a white pawn double advance (Black is the active color) or else be the digit "6" after a black pawn double advance (White being the active color). An en passant target square is given if and only if the last move was a pawn advance of two squares. Therefore, an en passant target square field may have a square name even if there is no pawn of the opposing side that may immediately execute the en passant capture.

5. the halfmove clock
The fifth field is a nonnegative integer representing the halfmove clock. This number is the count of halfmoves (or ply) since the last pawn advance or capturing move. This value is used for the fifty move draw rule.

6. the fullmove number
The sixth and last field is a positive integer that gives the fullmove number. This will have the value "1" for the first move of a game for both White and Black. It is incremented by one immediately after each move by Black.

a) the FEN for the starting position:

rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1

b) after the move 1. Be2-e4

rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq e3 0 1

c) after the move 1. Be2-e4 Bc7-c5

rnbqkbnr/pp1ppppp/8/2p5/4P3/8/PPPP1PPP/RNBQKBNR w KQkq c6 0 2

d) after the move 1. Be2-e4 Bc7-c5 2. Sg1-f3

rnbqkbnr/pp1ppppp/8/2p5/4P3/5N2/PPPP1PPP/RNBQKB1R b KQkq - 1 2

e) advanced game

For two kings on their home squares and a white pawn on e2 (White to move) with thirty eight full moves played with five halfmoves since the last pawn move or capture:

4k3/8/8/8/8/8/4P3/4K3 w - - 5 39

the long notation in the game manager under ("last move")

In the game-manager the last move is shown in the long form of the algebraic notation, so that the starting-square is shown completely.
For example:

• Qd1-f3  =  Queen from square d1 to square f3.
• b7-b5  = Pawn from square b7 to square b5.
• e4xd5  =  Pawn capture move from square e4 to square d5 .
• Qd8-a5+  =  Queen checking move from square d8 to square a5
• b2-b1=Q  = Pawn from square b2 to square b1: pawn exchanged for a queen!

Other letters and there meanings:

• O-O  = kingside (or short) castling
• O-O-O  = queenside (or long) castling
• x  = capture move
• +  = checking move
• #  = checkmating move
• e.p.  = En passant capture move
• (=)  = drawn
• =Q  = Pawn promotion (here: pawn exchanged for a queen)

• Laws of Chess - The nature and objectives of the game of chess

• Laws of Chess - The initial position of the pieces on the chessboard

• Laws of Chess - The moves of the pieces

• Laws of Chess - The completion of the game

• Laws of Chess - time-limit, time exceeding, leave

• Laws of Chess - the notation

• Laws of Chess - chessclubs, tournaments

• Laws of Chess - Chess960