Algebraic notation is a way to record chess games. Each square is given a specific label. Starting at White's left and Black’s right, the files are labeled from left to right with letters of the alphabet from a-h; the ranks are labeled from 1-8.
Movements of pieces are recorded by using a letter to designate a piece. Queens are denoted by Q (assuming the English language is being used), rooks by R, bishops by B, knights by N, and kings by K. The letters must be capitalized. Pawns have no letter, so if a pawn moves, we just write the square which it moves to.
The letter of the piece, where applicable, is the first thing written in a scoring blank. There is no other label if only one piece of that type can move to a square. However, if two or more pieces are the same and have the same color can both move to a square, the scorer will be obligated to denote which piece went to that square. For example, if the two black rooks were located on f8 and h2, for example, and one moved to f2. Because both two rooks can go to f2, by writing Rf or Rh (R8 or R2 can be used as well, but not usually), we can know which rook that went to f2 (f-file rook or h-file rook). Sometimes, the choice is made de facto if the two pieces are on the same rank or file (knights on c3 and c5, with one moving to a4: the number would be forced). Next comes the letter x if the move was a capture. If a pawn had been the capturing piece, the letter of their file (the file of the square of the pawn before it captured) would precede the x: ex... is a possible move in the opening. Then the square to which the piece ended its turn, such as exd5, Rf7, Bb5 are all possible moves.
Some moves give check: this is denoted by a plus sign after the move (Ex: Qe8+). Moves that give checkmate have been shown by two plus signs ++ or, much more common, a number sign #. Capturing en passant are sometimes written as e.p. after the move. King-side castling is represented by the symbol O-O (0-0), queen-side by O-O-O (0-0-0).
Promoting a Pawn (in this example, an e-file white pawn to a Queen) is notated by e8=Q, e8(Q), or e8/Q.
When scoring, the move number goes on the left hand column. White's move is given, followed by Black's in the same row. A new row begins for each move (although longer games may be read in two columns). Example:
- e4 e5
- Nf3 Nf6
When referring to a Black move, three dots precede it. Example:
A commentary might read, "2...Nf6 is Petrov's Defense".
Annotations[]
While technically not part of algebraic notation, several symbols can be used to evaluate moves:
- !: a good move
- !!: a brilliant move (often a sacrifice)
- ?: a bad move; a mistake.
- ??: a very bad move; a blunder.
- !?: an interesting move that may not be the best
- ?!: a dubious move that is not easily refuted but may end up being bad (incorrect move)
- Several annotations are used to represent the balance of the game (which player is more likely to win):
- =: More or less even
- +/=: Slight advantage for white
- =/+: Slight advantage for black
- +/-: Clear advantage for white
- -/+: Clear advantage for black
- +-: Winning advantage for white
- -+: Winning advantage for black
- ∞: Unclear
- =/∞: Whichever side is down in material has compensation.
- ⌓ (semicircle): Denotes a better move than the one played.
- □ (square): The only reasonable move, or the only one at all.