--- title: "Chess terms: Computer chess and analysis" url: "https://georgelichess.com/glossary/category/computer-chess.md" canonical_url: "https://georgelichess.com/glossary/category/computer-chess" last_updated: "2026-11-07" type: "index" summary: "30 plain definitions of chess terms about computer chess, such as Accuracy and Alpha-beta pruning, with related terms linked from each one." related: ["https://georgelichess.com/glossary.md", "https://georgelichess.com/glossary/category/tactics.md", "https://georgelichess.com/glossary/category/strategy.md", "https://georgelichess.com/glossary/category/endgames.md", "https://georgelichess.com/glossary/category/opening-concepts.md", "https://georgelichess.com/glossary/category/rules-notation.md", "https://georgelichess.com/glossary/category/tournaments-ratings-titles.md", "https://georgelichess.com/glossary/category/time-controls.md", "https://georgelichess.com/glossary/category/training-psychology.md"] --- # Chess terms: Computer chess and analysis > **For AI agents:** the complete index of GeorgeLiChess pages is [llms.txt](https://georgelichess.com/llms.txt). Every page is also served as markdown at its URL plus .md. 30 plain definitions of chess terms about computer chess, such as Accuracy and Alpha-beta pruning, with related terms linked from each one. 30 chess terms about computer chess. - [Accuracy](https://georgelichess.com/glossary/accuracy.md): 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. - [Alpha-beta pruning](https://georgelichess.com/glossary/alpha-beta-pruning.md): Alpha-beta pruning is a search technique that skips branches of the move tree that cannot change the minimax result, letting engines look much deeper using the same amount of computing time. - [Average centipawn loss](https://georgelichess.com/glossary/average-centipawn-loss.md): Average centipawn loss, or ACPL, is the mean amount of evaluation a player gave up per move compared with the engine's best choice, measured in hundredths of a pawn, so lower figures mean cleaner play. - [Best move](https://georgelichess.com/glossary/best-move.md): The best move is the move an engine rates highest in a given position after searching, usually shown first in its list of candidate lines and marked with the strongest evaluation. - [Blunder](https://georgelichess.com/glossary/blunder.md): 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. - [Blunder check](https://georgelichess.com/glossary/blunder-check.md): A blunder check is a quick test, made by a person before moving or by software afterward, that looks for a move which hangs material, allows a tactic or loses the game outright. - [Brilliant move](https://georgelichess.com/glossary/brilliant-move.md): A brilliant move is a label some analysis tools give to a strong, hard-to-find move, often a sacrifice, that the engine confirms keeps or improves the position despite looking risky. - [Centipawn](https://georgelichess.com/glossary/centipawn.md): 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. - [Chess engine](https://georgelichess.com/glossary/chess-engine.md): 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. - [Database](https://georgelichess.com/glossary/database.md): A chess database is a searchable collection of games, stored in a standard format, that lets a player look up positions, study opponents, and see how often moves have been played and what results they scored. - [Endgame tablebase](https://georgelichess.com/glossary/endgame-tablebase.md): An endgame tablebase is a precomputed database that gives the exact result and best moves for every position with a small number of pieces, so engines can play those endgames perfectly. - [Engine analysis](https://georgelichess.com/glossary/engine-analysis.md): 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. - [Evaluation](https://georgelichess.com/glossary/evaluation.md): 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. - [Evaluation bar](https://georgelichess.com/glossary/evaluation-bar.md): 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. - [Fair play](https://georgelichess.com/glossary/fair-play.md): Fair play is the rule that every game must be decided by the players' own thinking, which means no engine help, no advice from others during play and no tricks that distort a result. - [Game review](https://georgelichess.com/glossary/game-review.md): A game review is an automatic engine pass over a finished game that marks each move, shows how the evaluation changed and points out the turning points, mistakes and missed chances. - [Inaccuracy](https://georgelichess.com/glossary/inaccuracy.md): An inaccuracy is the mildest error label in game review, given to a move that is playable but gives up a small amount of advantage compared with the engine's better alternative. - [Minimax](https://georgelichess.com/glossary/minimax.md): Minimax is a decision method in which one side tries to maximize the evaluation while the opponent tries to minimize it, forming the basis of how traditional chess engines choose moves. - [Missed win](https://georgelichess.com/glossary/missed-win.md): A missed win is a game review label for a move that fails to take a clearly winning continuation, so a decisive advantage shrinks to something much smaller or disappears entirely. - [Mistake](https://georgelichess.com/glossary/mistake.md): A mistake is a game review label for a move that clearly worsens a position, costing a meaningful share of the advantage, though it is less severe than a blunder that throws the game away. - [Neural network engine](https://georgelichess.com/glossary/neural-network-engine.md): 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. - [Opening book](https://georgelichess.com/glossary/opening-book.md): An opening book is a database of opening moves and positions that an engine or program consults to play known theory quickly, instead of calculating each early move from scratch. - [Opening explorer](https://georgelichess.com/glossary/opening-explorer.md): An opening explorer is a tool that shows, for any position reached from the start, which moves players have chosen in past games and how often each move led to a win, draw or loss. - [Principal variation](https://georgelichess.com/glossary/principal-variation.md): The principal variation is the line of best play for both sides that an engine has found, shown as a sequence of moves and tied to the evaluation it reports. - [Puzzle rating](https://georgelichess.com/glossary/puzzle-rating.md): A puzzle rating is a number that estimates how hard a tactical puzzle you can reliably solve, and it rises and falls as you solve or fail puzzles of known difficulty, much like a game rating. - [Puzzle theme](https://georgelichess.com/glossary/puzzle-theme.md): A puzzle theme is a label for the tactical idea a puzzle teaches, such as a fork, a pin or a back rank mate, so that training can be grouped by pattern and weaknesses can be targeted directly. - [Search depth](https://georgelichess.com/glossary/search-depth.md): Search depth is how many moves ahead an engine has looked in a position, counted in half-moves called plies, and deeper searches generally give more reliable evaluations and moves. - [Stockfish](https://georgelichess.com/glossary/stockfish.md): Stockfish is a free, open-source chess engine developed by a worldwide community, widely regarded as one of the strongest engines available and used by many analysis websites and apps. - [Syzygy tablebases](https://georgelichess.com/glossary/syzygy-tablebases.md): Syzygy tablebases are a compact set of endgame tablebases created by Ronald de Man that cover endgames up to seven pieces and are widely used by modern chess engines. - [Winning chances](https://georgelichess.com/glossary/winning-chances.md): Winning chances are an estimate of how likely each side is to win from a position, often converted from the engine's evaluation into a percentage so that the same advantage reads differently at different levels. [All chess terms](https://georgelichess.com/glossary.md) [Book your first lesson](https://georgelichess.com/book.md) and George Li reviews your games and builds a study plan around them. Questions about lessons: write to hello@georgelichess.com. ## Related - [Chess terms glossary: plain definitions](https://georgelichess.com/glossary.md) - [Chess terms: Tactics and combinations](https://georgelichess.com/glossary/category/tactics.md) - [Chess terms: Strategy](https://georgelichess.com/glossary/category/strategy.md) - [Chess terms: Endgames](https://georgelichess.com/glossary/category/endgames.md) - [Chess terms: Opening concepts](https://georgelichess.com/glossary/category/opening-concepts.md) - [Chess terms: Rules, notation and equipment](https://georgelichess.com/glossary/category/rules-notation.md) - [Chess terms: Tournaments, ratings and titles](https://georgelichess.com/glossary/category/tournaments-ratings-titles.md) - [Chess terms: Time controls and formats](https://georgelichess.com/glossary/category/time-controls.md) - [Chess terms: Training and psychology](https://georgelichess.com/glossary/category/training-psychology.md)