Algebraic Chess Notation
We use algebraic chess notation to represent chess positions without posting a full chessboard. This allows players to converse about chess positions clearly without a board in front of us. Imagine the chess board as a 2D plot. Below is the table I made to explain this notation in my paper How Stockfish Works: An Evaluation of the Databases Behind the Top Open-Source Chess Engine. I will post more about this paper when I’ve finished editing it.
| Symbol | Meaning |
|---|---|
| a-h | file from white’s left to right |
| 1-8 | rank from white to black |
| R, N, B/S, Q, K | Rook, Knight, Bishop, Queen, King |
| x | capture; the piece that was at this location is removed |
| + | a note that the king is threatened |
| # or ++ | checkmate; a note that this is the reason for the end of the game |
| = | promoted to; a pawn arriving at the opposite side of the board is promoted to another piece, often a queen. |
| 0-0 | castle on the kings side; move to positions (B - Kg8 Rf8 ; W - Kf1 Rg1) (if neither has moved before this point in the game) |
| 0-0-0 | castle on the queens side; (B - Kd8 Rc8 ; W - Kc1 Rd1) (if neither has moved before this point in the game) |
| e.p. | en passant capture (non-SAN), a note that a pawn was taken by another pawn passing it. When a pawns first move is a two space move (from 7 to 5 for black or 2 to 4 for white) it can be captured by moving behind it to the 6th rank (white taking black) or 3rd rank (black taking white). |
| ?, ??, !, !! | editorial comments, weak, very weak, strong, very strong |
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| Coordinates in Algebraic Chess Notation |
I encourage you to explore additional background information provided by the online book Building Skills in Python.
Written on April 11, 2013