Editing Bitboard (section)

===Standard===
[[File:SCD algebraic notation.svg|right|[[Algebraic notation (chess)|Algebraic notation]]|frame]]
In bitboard representations, each bit of a 64 bit word (or double word on 32-bit architectures) is associated with a square of the chessboard.  Any mapping of bits to squares can be used, but by broad convention, bits are associated with squares from left to right and bottom to top, so that bit 0 represents square a1, bit 7 is square h1, bit 56 is square a8 and bit 63 is square h8.

Many different configurations of the board are usually represented by their own bitboards including the locations of the kings, all white pawns, all black pawns, as well as bitboards for each of the other piece types or combinations of pieces like all white pieces.  Two attack bitboards are also universal: one bitboard per square for all pieces attacking the square, and the inverse bitboard for all squares attacked by a piece for each square containing a piece.  Bitboards can also be constants like one representing the first rank, which would have one bits in positions 0 - 7.  Other local or transitional bitboards like "all spaces adjacent to the king attacked by opposing pieces" may be collated as necessary or convenient.<ref name="Atkin_1977"/>

An example of the use of the bitboards would be determining whether a piece is '' [[Glossary of chess#en prise|en prise]]'': bitboards for "all friendly pieces guarding ''space''" and "all opposing pieces attacking ''space''" would allow matching the pieces to readily determine whether a target piece on ''space'' is ''en prise''.

One of the drawbacks of standard bitboards is collating the attack vectors of the sliding pieces (rook, bishop, queen), because they have an indefinite number of attack spaces depending on other occupied spaces. This requires several lengthy sequences of masks, shifts and complements per piece.