Evaluation
An evaluation is a numerical judgment of who stands better in a position, usually given in pawns from White’s point of view, where positive favors White and negative favors Black.
Also called: engine evaluation
An evaluation turns a position into a single number. Most engines express it in pawns from White’s side: plus one means White is roughly a pawn better, minus one means Black is. A value near zero means the position is balanced. When a forced checkmate is found, the engine shows a mate in some number of moves instead of a pawn score.
The number comes from many factors at once, including material, piece activity, king safety, pawn structure and the threats available to each side. That is why a position can show a small evaluation even when one side has extra material but poor piece placement.
When you read an evaluation, remember two things. First, small differences rarely matter in practice. A move that changes the score from plus 0.3 to plus 0.1 is not a blunder, and a human opponent will not exploit it. Second, a large advantage on screen still needs technique to convert. Use big swings as signals to study a mistake, but do not obsess over decimals. Compare the evaluation before and after your move to see how much a decision cost you.
It sits close to Evaluation bar. The evaluation bar is a vertical or horizontal gauge beside the board that shows, with a bar of black and white, which side the engine thinks is better and by roughly how much.
A neighboring idea is Neural network engine. A neural network engine uses a trained neural network to evaluate positions, and NNUE, the efficiently updatable neural network added to Stockfish, combines such an evaluation with fast traditional search.
Compare it with Centipawn. A centipawn is one hundredth of a pawn, the small unit engines use to report evaluations, so a score of 150 centipawns means the engine thinks one side is about one and a half pawns better.
Computer terms such as "Evaluation" are most useful next to a coach who reads your games with you, which is how a first lesson with George Li works.
Related terms
A centipawn is one hundredth of a pawn, the small unit engines use to report evaluations, so a score of 150 centipawns means the engine thinks one side is about one and a half pawns better.
The evaluation bar is a vertical or horizontal gauge beside the board that shows, with a bar of black and white, which side the engine thinks is better and by roughly how much.
A chess engine is a computer program that searches positions and evaluates moves, usually playing and analyzing far stronger than any human, and it is used for analysis, preparation and play against a machine.
Engine analysis is the use of a chess program to search a position and report which moves are strongest, along with a numeric evaluation and the lines it expects both sides to follow.
A blunder is a very serious error, such as leaving a piece undefended or missing a decisive tactic, that swings the evaluation so far that a good position turns bad or a bad one becomes lost.
Accuracy is a percentage produced by analysis software that summarizes how closely a player's moves matched the engine's preferred choices over a game, with higher numbers meaning fewer costly errors.
Guides that go further
What to decide first, the questions to ask, what a first lesson should show and the red flags to avoid.
How much does chess coaching cost?
Published rates for private, group and subscription chess coaching, with the source and the date of each.
A game review, a read on your level and a written study plan from George Li.
Want to spot this in your own games?
A first lesson starts with your games: George reviews them and builds a study plan around what he finds.