How do I model a chessboard when programming a computer to play chess?

Question

What data structures would you use to represent a chessboard for a computer chess program?

Answer 1

Initially, use an 8 * 8 integer array to represent the chess board.

You can start programing using this notation. Give point values for the pieces. For example:

**White**
9 = white queen
5 = white rook
3 = bishop
3 = knight
1 = pawn

**black**
-9 = white queen
-5 = white rook
-3 = bishop
-3 = knight
-1 = pawn

White King: very large positive number
Black King: very large negative number

etc. (Note that the points given above are approximations of trading power of each chess piece)

After you develop the basic backbones of your application and clearly understand the working of the algorithms used, try to improve the performance by using bit boards.

In bit boards, you use eight 8 -bit words to represent the boards. This representation needs a board for each chess piece. In one bit board you will be storing the position of the rook while in another you will be storing the position of the knight... etc

Bit boards can improve the performance of your application very much because manipulating the pieces with bit boards are very easy and fast.

As you pointed out,

Most chessprograms today, especially those that run on a 64 bit CPU, use a bitmapped approach to represent a chessboard and generate moves. x88 is an alternate board model for machines without 64 bit CPUs.