Algebraic Notation: how to read and write chess moves

Algebraic notation gives each of the 64 squares its own name and lets you write any move in a handful of characters, usually two or three. e4 means a pawn moved to the e4 square. Nf3 means a knight moved to f3, where N stands for knight. It is the common language of chess: it lets you read any book, follow any broadcast and, above all, review your own games.

Every square has an address

The board is an 8 by 8 grid. The eight vertical files get letters, a through h, running left to right from White's side. The eight horizontal ranks get numbers, 1 through 8, counting up from White's side. A square name is the file letter plus the rank number, always in that order and always lowercase: a1, e4, h8.

A square name is absolute: e4 is e4 for White and for Black, even when the board is flipped on the screen of the player with the black pieces. It also gives you a one second check of the setup. a1, the bottom left corner from White's side, is a dark square, and h1, the bottom right corner, is light. If the right hand corner is dark, the board is turned the wrong way.

The piece letters

The capital letter of the piece goes before the destination square. The international standard, used by websites, apps and the PGN files that store games, takes its initials from English. Books in other languages use their own.

• King: K in English, R (rei) in Portuguese.
• Queen: Q in English, D (dama) in Portuguese.
• Rook: R in English, T (torre) in Portuguese.
• Bishop: B in both, the one letter that matches.
• Knight: N in English, C (cavalo) in Portuguese.
• Pawn: no letter at all. When a move starts straight with a square, like e4 or d5, a pawn made it.

The trap is the letter R: it is the rook in English and the king in Portuguese. Nf3 and Cf3 are the same move written in two alphabets. Since nearly every piece of chess software uses the English letters, every example from here on follows that standard.

Writing a single move

The base form is piece letter plus destination square: Nf3, Bc4, Rd1. A pawn gets the square alone: e4, d5, h6. On top of that base there are six marks, and together they cover everything a game can throw at you.

• Capture, x: Bxc6 is the bishop taking whatever stood on c6. A pawn uses its file of origin in place of a letter: exd5 is the e file pawn capturing on d5.
• Check, +: Qh5+ is the queen going to h5 and attacking the enemy king.
• Checkmate, #: Qxf7# captures on f7, delivers mate and ends the game. Older books write ++ for mate, while other authors use ++ for double check, so # is the safer symbol.
• Castling, O-O and O-O-O: O-O is short castling (king side), O-O-O is long castling (queen side). It counts as a king move, which is why it carries no piece letter.
• Promotion, =: e8=Q is a pawn reaching the eighth rank and becoming a queen. Another piece is allowed: exd8=N+ captures on d8, promotes to a knight and gives check.
• En passant: written like any pawn capture, exd6, sometimes with e.p. added.

Disambiguation: two pieces, one square

Nd2 only works if a single knight can reach d2. When two of them can, the notation has to say which one moved, and the rule has three steps applied in this order.

1. Different files: give the file of origin. Nbd2 is the knight from the b file.
2. Same file: give the rank. With rooks on e1 and e5, the lower one going to e2 is R1e2.
3. Neither file nor rank settles it, which normally happens only after promotions: then you write the full square of origin, Qh4e1.

If the move is also a capture, the x comes after the disambiguation: Ngxe5. The reverse holds too: when only one piece can reach the square, leave the origin out. Writing too much is as wrong as writing too little.

The annotation symbols

After the move come the evaluation symbols. They are not part of the move itself, they are the annotator's opinion, and they save whole paragraphs of prose.

• ! a strong move, hard to find.
• !! a brilliant move.
• ? a mistake.
• ?? a blunder, the kind that decides the game.
• !? an interesting move, risky, with a real idea behind it.
• ?! a dubious move, probably bad.

Two formatting details finish the set. When a black move is quoted on its own, three dots come first: 3...Nf6 is the third move for Black. And the final score appears as 1-0 (White won), 0-1 (Black won) or ½-½ (a draw).

A short game, move by move

1.e4 e5 are pawns, which is why they carry no letter. 2.Nf3 Nc6 develops the knights. 3.Bc4 d6 puts the white bishop on the f7 diagonal and frees the black light squared bishop. 4.Nc3 Bg4 pins the f3 knight: if it moves, the white queen on d1 is exposed to that bishop.

5.Nxe5!? is the bait. The knight grabs the e5 pawn and pretends to forget the queen. The right answer is 5...Nxe5, leaving Black a piece up for a pawn. Taking the gift with 5...Bxd1?? loses on the spot: 6.Bxf7+ forces 6...Ke7, the only legal move, because the e5 knight defends the bishop and also covers d7, and 7.Nd5# closes the net.

Why writing moves down speeds you up

A player who records games can go back, and that is the whole difference. A game nobody wrote down turns into a vague feeling, something like "I think I lost it near the end", and a vague feeling cannot be fixed. With the moves written, you reopen the exact position where the game turned, test the move you did not play and find the mistake you keep repeating. Reviewing your own games is the fastest way to improve.

1. Mark the move where the position turned. There is almost always exactly one.
2. Go back one move and write down the alternative you did not play.
3. Record the reason in one sentence: hanging piece, exposed king, moved too fast.
4. Do this for ten games. The same reason keeps coming back, and that is the one to train.