fourteen squares from any square of the board — the one piece that does not care where it stands
Built as a memo rather than a table: the thing worth hanging it up for reads across the room, with the full reference in smaller type below it.
Three sizes in one archive — from a sheet on the fridge to a poster on the wall.
The moves are FIDE Laws of Chess in force from 1 January 2023, article 3. Square counts are walked, not quoted.
The rook holds fourteen squares from any one of the sixty-four squares of the board. Not roughly the same but exactly as many: seven along the file and seven along the rank come out of a corner and out of the middle alike. An eight-by-eight board is built so that what is lost on one side always comes back on the other.
Among the six pieces it is the only one like this. A knight in a corner holds 2 squares against 8 in the middle, a king 3 against 8, a bishop 7 against 13, a queen 21 against 27. That is why the advice to bring pieces towards the centre is not applied to a rook: in squares it gains nothing at all.
This does not mean it makes no difference where a rook stands. Its advantage is of another kind and is not counted in squares: an open file, the seventh rank, two rooks connected on a line. But the plain number of available squares — the thing other pieces are measured by — is constant for it.
Why the numbers can be trusted. Every countable number here is computed from data rather than typed in, and the sheet must pass 7 independent checks before it is allowed to build — how many items there are, the order they come in, and the claim in the highlighted box itself. If one fails, there is no file.
four FIBA sizes with their circumference and mass — and why the rules set a bounce, not a pressure
Law 2, three codes of the game, five sizes and three FIFA quality marks — what a ball must survive
eleven sports at true relative size — circumference, mass, pressure, and who sets them
a diagonal at any distance — and the half of the board that will never come