Algebraic notation is a notation system that allows players to identify squares on the chess board and keep a record of the moves that are performed during a chess game. This page explains algebraic notation.
Identifying Squares on the Board
In algebraic notation, the ranks (rows) are identified with numbers 1 through 8, and the files (columns) are identified with letters a through h. Ranks 1 and 2 are where white's pieces start, and ranks 7 and 8 are where black's pieces start. The board below illustrates this.
A square is identified first by the file, then by the rank. In other words, the letter is first, followed by the number. For example, white's queen is on d1 in the board above, while black's queen is on d8.
Each chess piece (except for pawns) is identified by a letter, as shown in the following table.
|N (since K is already taken)|
A move in chess is recorded by the letter of the moved piece (if not a pawn) followed by the square that the piece was moved to. For example, Nf6 indicates that the knight was moved to f6.
To record an entire game in algebraic notation, each pair of moves (white, then black) is preceded by a number. For example, white and black's first moves would be recorded as shown to the right of the board.
And white's next move would be recorded like so:
Referring to Single Moves
Sometimes you may want to refer to a single move rather than display the entire list of moves for the game. If referring to a single move by white, you can simply note the move number followed by the move. For example, 2. Nf3 says that white's second move of the game was Nf3. To refer to a single move by black, however, you put an ellipsis after the move number. For example, 1. … e5 says that the first move by black was e5.
Notation for Captures
If a piece is captured, the move is recorded by putting the capturing piece's letter first (or the file letter, for pawns), followed by an x, followed by the destination square. For example, we start with the position here:
If black's pawn chooses to capture white's, the notation is 2. … exd4.
If white goes on to capture that black pawn with the queen, it would be recorded as 3. Qxd4.
Clearing Up Ambiguous Moves
In some cases, recording a piece's letter and its destination square is not sufficient, because two of the same type of piece could both go to that destination square. For example:
Both rooks can move to d8. Since both rooks are on the same rank, note the file of departure after the piece's letter. For example, if the rook on the a file moves to d8, it is recorded as Rad8.
In the next example, the rooks are both on the same file. Both can move to a4. Since both rooks are on the same file, note the rank of departure after the piece's letter. For example:
If the rook on rank 8 moves to a4, it is recorded as R8a4.
When the pieces making an ambiguous move are not on the same file or rank, the file takes precedence. For example, both knights in the following diagram could go to d4.
To specify which knight moves to that square, note the file of departure after the piece's letter. For example, if the knight on the f file goes to d4, it is recorded as Nfd4.
In rare cases when multiple pawns have been promoted to the same piece, it may not be sufficient to note just the rank or just the file of the piece that moved. In this case, both must be noted. For example:
If the queen at b1 moves to e4, it is noted as Qb1e4.
Notation for Special Situations
The notation for castling kingside is O-O and the notation for castling queenside is O-O-O. These can either be zeroes or uppercase letter Os. In the example below, white has castled queenside and black has castled kingside.
Pawn promotion is denoted by noting the destination square followed by the letter of the piece to which the pawn was promoted. For example:
The pawn moved to e8 and was promoted to a queen, so it is recorded as e8Q. Some systems use alternative notation such as e8=Q or e8(Q).
Check and Checkmate
When the king is put in check, the move that put the king in check is followed by a plus sign. In the diagram below, the queen will put the king in check by going to e8. This is noted as Qe8+.
When checkmate occurs, it is noted with a # instead of a plus sign, as shown below.
The End of the Game
When the game ends by checkmate or resignation, the end of the game is noted as 1-0 if white won, or 0-1 if black won. If the game ended in a draw (such as by stalemate), the draw is noted as ½-½.