Objective evaluation

An objective evaluation asks what result or advantage a position supports if both sides find their strongest replies. It may judge one side better, the position roughly equal, or, when the evidence is sufficiently clear, the position won, drawn, meaning the game ends without a winner, or lost. The central question is what the position allows, not which result seems most likely between two particular people.

The assessment compares material, meaning the pieces and pawns each side retains; king safety; piece activity; pawn structure, or how the pawns are arranged; and concrete variations, meaning calculated move sequences. A chess engine, a program that calculates and scores positions, can help, but its number is not the definition of objective evaluation. The score depends on the position searched, calculation time, settings, and interpretation.

Objective does not mean infallible

In many positions the full truth is unknown. An objective evaluation is the best judgment supported by the available analysis, and it can change when a defense, a refutation, or a sequence analyzed more deeply is found. It must also be separated from practical chances: an objectively lost position may still be very difficult for a human to win.