Chess annotation symbols
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When annotating chess games, commentators frequently use widely recognized annotation symbols. Question marks and exclamation points that denote a move as bad or good are ubiquitous in chess literature. Some publications intended for an international audience, such as the Chess Informant, have a wide range of additional symbols that transcend language barriers.
The common symbols for evaluating the merits of a move are "??", "?", "?!", "!?", "!", and "!!". In these cases, the corresponding symbol is juxtaposed in the text immediately after the move (e.g. Re7? or Kh1!?, see algebraic chess notation).
Use of these annotation symbols is subjective, as different annotators use the same symbols differently. Moreover, an annotator's use of symbols is often influenced by the player's strength: a positional misjudgment that an annotator might give a "??" if played by a strong grandmaster might pass unremarked if played by a beginner.
Annotators' use of punctuation may also be influenced by the result of the game regardless of the actual quality of the move; this tendency is sometimes referred to as "annotation by result".
|This article uses algebraic notation to describe chess moves.|
Move evaluation symbols, by increasing effectiveness of the move:
?? (Blunder) 
The double question mark "??" indicates a blunder, a bad mistake. Typical moves which receive double question marks are those that overlook a tactic that wins substantial material or overlook a checkmate. A "??"-worthy move usually results in an immediately lost position. Occasionally, the sign is used for a move which transforms a won position into a draw, perhaps because the annotator feels that the mistake is unworthy of the player's skill level. They occur at all levels of play to all human competitors.
? (Mistake) 
A single question mark "?" after a move indicates that the annotator thinks that the move is a poor one that should not be played. These often lead to loss of tempo or material. The nature of the mistake may be more strategic than tactical; in some cases, the move receiving a question mark may be one for which it is difficult to find a refutation. A move that overlooks a forthcoming brilliant combination from the opponent would rarely receive more than one question mark, for example.
Whether a single or double question mark is used is subjective and may depend on the player's strength. For instance, if a beginner makes a serious strategic error (for instance, accepting gratuitous pawn weaknesses or exchanging into a lost endgame) or overlooks a tactical sequence, this might be explained by the beginner's lack of skill and be given only one question mark. If a master were to make the same move, some annotators might use the double question mark to indicate that one would never expect a player of the master's strength to make such a weak move.
?! (Dubious move) 
This symbol is similar to the "!?" (below) but usually indicates that the annotator believes the move to be dubious, questionable but possibly having merits. The "?!" may also indicate that the annotator believes the move is deserving of criticism but not bad enough to warrant a "?". A sacrifice leading to a dangerous attack which the opponent should be able to defend against if they play well may receive a "?!". Alternatively, this may denote a move that is objectively bad, but sets up an attractive trap.
!? (Interesting move) 
The "!?" is one of the more controversial symbols. Different books have slightly varying definitions. Among the definitions are "interesting, but perhaps not the best move", "move deserving attention", "enterprising move" and "risky move". Usually it indicates that the move leads to exciting or wild play but that the objective evaluation of the move is unclear. It is also often used when a player sets a cunning trap in a lost position. Typical moves receiving a "!?" are those involving speculative sacrifices or dangerous attacks which might turn out to be strategically deficient.
! (Good move) 
While question marks indicate bad moves, exclamation points ("!") indicate good moves—especially ones which are surprising or involve particular skill. The symbol may also be interpreted as "best move". Annotators are usually somewhat conservative with the use of this symbol.
Reasons for awarding the symbol vary widely between annotators; among them are strong , well-timed breakthroughs, sound sacrifices, moves that set traps in lost positions, moves that avoid such traps, and good psychological choices in the opening.
!! (Brilliant move) 
The double exclamation point ("!!") is used for very strong moves such as sound sacrifices of large amounts of material and counter-intuitive moves that prove very powerful. For example, in what is known as the Game of the Century, 13-year-old Bobby Fischer's decision to sacrifice his queen for a strategic attack was awarded by annotators a double exclamation point.
A few writers have used three or more exclamation points ("!!!") for an exceptionally brilliant move. For example, in Rotlewi-Rubinstein 1907, Hans Kmoch awarded Rubinstein's 22...Rxc3 three exclamation points. Likewise, an exceptionally bad blunder may be awarded three or more question marks ("???"). The general consensus among chess writers is that these symbols are unnecessary.
A few writers have used unusual combinations of question marks and exclamation points (e.g. "!!?", "?!?", "??!") for particularly unusual or controversial moves, but these have no generally accepted meaning, and are typically used for humorous or entertainment purposes.
At times an annotation symbol may be put in parentheses, e.g. "(?)", "(!)". Different writers have used these in different ways; for example Simon Webb used "(?)" to indicate a move which is objectively sound, but was in his opinion a poor psychological choice, while Robert Hübner (see below) used it to indicate a move which is inaccurate and makes the player's task more difficult.
There are some systems which use these symbols in different ways.
In his 1992 book Secrets of Rook Endings and other books in the series (Secrets of Minor-Piece Endings and Secrets of Pawnless Endings), John Nunn uses these symbols in a more specific way in the context of endgames where the optimal line of play can be determined with certainty:
- ! The only move which maintains the current evaluation of the position: if the position is theoretically drawn, this is the only move which does not lose; if the position is theoretically won, this is the only move which secures the win. An "!" is used no matter how trivial the move in question; the only exception is if it is the only legal move.
- !! A particularly difficult-to-find "!" move.
- ? A move which negatively affects the evaluation of the position: if the position had been drawn before the move, it is now lost; if won before the move, it is now drawn or lost.
- ?? An obviously bad "?" move.
- !? A move which makes the opponent's task harder or one's own task easier; for example, in a theoretically lost position, a move which forces the opponent to find several "!" moves in order to win.
- ?! A move which makes the opponent's task easier or one's own task harder; for example, in a theoretically won position, a move which requires several subsequent "!" moves in order to win (Nunn 1999).
This convention has been used in some later works, such as Fundamental Chess Endings and Secrets of Pawn Endings by Karsten Müller and Frank Lamprecht, but it can be safely assumed the convention is not being used unless there is a specific note otherwise. The Nunn convention cannot be used to annotate full games because the exact evaluation of a position is generally impractical to compute.
In 1959, Euwe and Hooper made the same use of the question mark, "... a decisive error...".
German grandmaster Robert Hübner prefers an even more specific and restrained use of move evaluation symbols: "I have attached question marks to the moves which change a winning position into a drawn game, or a drawn position into a losing one, according to my judgment; a move which changes a winning game into a losing one deserves two question marks … I have distributed question marks in brackets to moves which are obviously inaccurate and significantly increase the difficulty of the player's task ... There are no exclamation marks, as they serve no useful purpose. The best move should be mentioned in the analysis in any case; an exclamation mark can only serve to indicate the personal excitement of the commentator."
When the solution to a certain chess problem is given, there are also some conventions that have become a common practice:
- move is marked with at least one "!"
- move is marked with "?"
- Refutation to a try move is marked with "!"
- When is a part of the thematic content of a problem, avoided duals (if listed) are marked with "?"
These symbols indicate the strategic balance of the game position:
= (Equal) 
Even position: White and Black have more or less equal chances.
+/= or ⩲ (Slight plus for White) 
Slight advantage: White has slightly better chances.
=/+ or ⩱ (Slight plus for Black) 
Slight advantage: Black has slightly better chances.
+/− or ± (Clear plus for White) 
Clear advantage: White has the upper hand. It is also written as ±; the other similar symbols can be written in this style as well.
−/+ or ∓ (Clear plus for Black) 
Clear advantage: Black has the upper hand. It is also written as ∓; the other similar symbols can be written in this style as well.
+ − (Decisive advantage for White) 
Decisive advantage: White has a winning advantage.
− + (Decisive advantage for Black) 
Decisive advantage: Black has a winning advantage.
∞ (Unclear) 
Unclear position: It is unclear who (if anyone) has an advantage. Often used when a position is highly asymmetrical, e.g. Black has a ruined pawn structure but dangerous active piece-play.
=/∞ (Compensation) 
With compensation: Whoever is down in has compensation for it. Can also denote a position that is unclear, but appears to the annotator to be approximately equal. (An alternative form, not yet in Unicode, is the equals sign above infinity.) Chess Informant has given two distinct glyphs for the same concept: denotes the circumstance where White has compensation for Black's material advantage, and denotes the circumstance where Black has compensation for White's material advantage.
Other symbols 
There are other symbols used by various chess engines and publications, such as Chess Informant and Encyclopaedia of Chess Openings, when annotating moves or describing positions. Many of the symbols now have Unicode encodings, but quite a few still require a special chess font with appropriated characters.
- ⌓ Better: Indicates a better move than the one played.
- □ Only: The only reasonable move, or the only move available.
- Δ "With the Idea...": Indicates the future plan this move supports.
- ∇ Countering: Indicates the opponent's plan this move defends against.
- TN or N Novelty: A move that is a .
Positions or conditions
- ↑ Initiative: Indicates an advantage in initiative.
- → Attack: With an .
- ⇄ Counterplay: Indicates that the player has .
- ↻ or ↑↑ Development: Indicates a lead in .
- ○ Space: Indicates more owned by one player.
- ⊕ Time trouble, a.k.a. Zeitnot: Indicates the player had little time remaining on their clock.
- ⊙ Zugzwang
- "Chess Analysis Symbols" (PDF). chesscenter.net. C&O Family Chess Center. Archived from the original (PDF) on 2018-01-16. Retrieved 2014-07-29.
- Matanović, Aleksander, ed. (1973). Šahovski Informator [Chess Informant]. 14. Belgrade. pp. 8–9.
- Chess to Enjoy-Eternal Questions, published in Chess Life, March 2000, pp. 12-13.
- Euwe & Hooper, p. viii
- Twenty-five Annotated Games, published by Edition Marco, Verlag Arno Nickel, Berlin, 1996, pp. 7-8.
- "Chess Informant: System of Signs". Archived from the original on 2017-01-01. Uses FigurineCB webfont.
- Encyclopaedia of Chess Openings, Chess Informant (Šahovski informator), 1966.
- Euwe, Max; Hooper, David (1959), A Guide to Chess Endings, Dover (1976 reprint), ISBN 978-0-486-23332-1
- Müller, Karsten; Lamprecht, Frank (2001), Fundamental Chess Endings, Gambit Publications, ISBN 978-1-901983-53-1
- Nunn, John (1999), Secrets of Rook Endings, Gambit Publications, ISBN 978-1-901983-18-0