A chessboard is a used to play chess. It consists of 64 squares, 8 rows by 8 columns, on which the chess pieces are placed. It is square in shape and uses two colours of squares, one light and one dark, in a chequered pattern. During play, the board is oriented such that each player's near-right corner square is a light square. The columns of a chessboard are known as , the rows are known as , and the lines of adjoining same-coloured squares (each running from one edge of the board to an adjacent edge) are known as . Each square of the board is named using algebraic, descriptive, or numeric chess notation; algebraic notation is the FIDE standard. In algebraic notation, using White's perspective, files are labeled a through h from left to right, and ranks are labeled 1 through 8 from bottom to top; each square is identified by the file and rank which it occupies. The a- through d-files comprise the , while the e- through h-files comprise the . History and evolution The earliest known ancestor of the chessboard is the Ashtāpada board. Among other games, it was used to play chaturanga, a historical precursor to chess, beginning around the 6th century in India. The board uses a single color for all squares and is divided into eight columns by eight rows, with marked squares called castles in the corners of each quadrant. Unlike in Ashtāpada, castles serve no function in chaturanga. The chessboard acquired its modern chequered pattern in the 10th century with the arrival of chess in Europe. This pattern was based on that of the then-5×5 draughts board. As a result of this change, each diagonal was now highlighted by a continuous sequence of same-coloured squares, which later facilitated the introduction of the modern bishop and queen movements in the 15th century. The Libro de los juegos (1283) contains a description of the chessboard, describing eight rows and columns as the ideal number, deeming the practice of chess on the 10×10 board too tiresome and on the 6×6 board too quick. In the 13th century, some players began using the convention that the first square of the far right column should be light-coloured; this convention was endorsed by Pedro Damiano at the end of the 15th century. In 2003, the ex-world champion Garry Kasparov faced the chess engine X3D Fritz in a