Answer: Centipawns

When you’re designing a chess computer program, you’re left with a particularly specific problem: how to evaluate and weigh the value of individual moves in the game when those moves don’t necessarily add up to the strategic value of the smallest loss in the game—the death of a pawn.

In order to help the program evaluate maneuvers that have a value (however small) and use that value to calculate a series of future moves, programmers use a measurement called a “centipawn”. Under the centipawn system, a pawn is worth 100 centipawns and each higher ranked piece is assigned a higher value of centipawns. Typically, knights and bishops are worth 300, a rook is 500, and so on.

The purpose of this odd arrangement is so that the value of moves that are worth less than the value of a pawn can be addressed in an easy and numeric fashion without resorting to the use of fractional values. In this manner, the computer program can easily and quickly assess a move, assign it a value of, say, “X”, then evaluate another move and assign it a value of, say, “Y”, and then select the most advantageous maneuver.