Centipawn loss

Centipawn loss, abbreviated CPL, measures one move. A chess engine, a program that analyzes continuations, compares its preferred option with the move that was played. The difference is expressed from the mover's perspective: the more the played move worsens that player's position relative to the best option, the larger the loss.

A loss of 0 means that, under the chosen analysis settings, the played move was best or tied for best. A loss of 80 means an approximate deterioration of 0.80 pawn units on the engine's scale. The measuring unit is the centipawn, not an actual piece.

The metric does not say that pawns were physically lost. A move may lose 200 centipawns without dropping material, for example by allowing a powerful attack. A move may also deliberately give up a piece with little or no CPL when doing so is the best way to gain enough activity, recover material, or deliver mate.

The value depends on the engine evaluation, search time, depth, engine version, and the site's handling of mates, already decided positions, and extreme scores. Two services may therefore assign different numbers to the same move. CPL indicates distance from a computer reference; by itself, it does not diagnose the mistake.