Chess annotation symbols
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 also tends to be influenced by the result of the game; in the 11th game of the 1972 World Championship, Spassky played a very surprising move, 14.Nb1, retreating the knight to its initial square. Spassky won the game, and the annotators invariably gave the move two exclamation points. Edmar Mednis observes that if Spassky had lost the game, the move would likely have been given two question marks instead.
|This article uses algebraic notation to describe chess moves.|
Move evaluation symbols 
Move symbols in increasing effectiveness of the move:
?? (Blunder) 
The double question mark "??" indicates a blunder, a very bad mistake. Typical moves which receive double question marks are those that overlook that the queen is under attack or overlook a checkmate. Whether a single or double question mark is used often depends 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.
? (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. However, the nature of the mistake may be more strategic than tactical; in some cases, the move receiving a question mark may be one that is difficult to find a refutation for.
?! (Dubious move) 
This symbol is similar to the "!?" (below) but usually indicates that the annotator believes the move to be objectively bad, albeit hard to refute. The "?!" is also often used instead of a "?" to indicate that the move is not all bad. A sacrifice leading to a dangerous attack which the opponent should be able to defend against if he plays well may receive a "?!". Alternatively, this may denote a move that is truly 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 and that the move is probably good. 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. Hence annotators are usually somewhat conservative with the use of this symbol; for example, they would not annotate a game thus: 1.e4! c5! 2.Nf3! d6! 3.d4! cxd4! 4.Nxd4! Nf6! 5.Nc3! All the moves of this main-line Sicilian Defence are good ones, but the players have demonstrated little skill by simply following well-known opening theory.
Once the players start making good choices when faced with difficult decisions, however, a few moves may receive exclamation points from annotators. Typical moves receiving exclamation points are strong opening novelties, well-timed breakthroughs, sound sacrifices, and moves that avoid falling into traps.
‼ (Brilliant move) 
The double exclamation point ("‼") is used to praise a move which the annotator thinks really shows the player's skill. Such moves are usually hard to find. These may include sound sacrifices of large amounts of material and moves that at first glance seem very counter-intuitive.
Alternate uses 
There are some systems which use these symbols in different ways.
The Nunn Convention 
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...".
Hübner's approach 
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."
Chess composition 
When the solution to a certain chess problem is given, there are also some conventions that have become a common practice:
- Key move is marked with at least one "!"
- Try move is marked with "?"
- Refutation to a try move is marked with "!"
- When dual avoidance is a part of the thematic content of a problem, avoided duals (if listed) are marked with "?"
Position evaluation symbols 
These symbols indicate the strategic balance of the game position:
- ∞ – Unclear: It is unclear who (if anyone) has an advantage. This is often used when a position is highly asymmetrical, such as Black having a ruined pawn structure but dangerous active piece-play.
- =/∞ – With compensation: Whoever is down in material has compensation for the material.
- = – Even position: White and Black have more or less equal chances.
- +/= (=/+) – Slight advantage: White (Black) has slightly better chances.
- +/− (−/+) – Advantage: White (Black) has much better chances. It is also written as ± for White advantage, ∓ for Black advantage; the other similar symbols can be written in this style as well.
- +− (−+) – Decisive advantage: White (Black) has a clear advantage.
Other symbols 
Some annotators put together even more question marks and exclamation points. For example, "???" or "????" might indicate a truly abysmal move, for example, 1.f3? e5 2.g4??? Qh4# (Fool's Mate); an extraordinarily brilliant move might receive "!!!" or even "!!!!"; and a fascinating but probably unsound move might receive "?!?" or "!?!". However, use of such symbols is not common.
- ○ – Space: Indicates more territory (space) owned by one player.
- ↑ – Initiative: Indicates an advantage in initiative.
- ↑↑ – Development: Indicates a lead in development. Also written ↻.
- ⇄ – Counterplay: Indicates that the player has counterplay.
- ∇ – Countering: Indicates the opponent's plan this defends against.
- Δ – Idea: Indicates the future plan this move supports.
See also 
- Edmar Mednis, How to Beat Bobby Fischer, Dover Publications, 1997, pp. 278–79. ISBN 0-486-29844-2.
- 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.
- Frank Marshall's spectacular 23...Qg3 in Levitsky-Marshall, Breslau 1912, a move that left the queen en prise to three different pieces yet won by force, reportedly moving the spectators to shower the board with gold pieces, is a frequent recipient of "!!!" E.g., Anthony Saidy and Norman Lessing, The World of Chess, Random House, 1974, p. 153, ISBN 0-394-48777-X; Frank J. Marshall, Marshall's Best Games of Chess, Dover Publications, 1960, p. 139, ISBN 0-486-20604-1. Reuben Fine gave the move "!!!!" Reuben Fine, The Middle Game in Chess, David McKay, 1952, p. 47.
- Encyclopaedia of Chess Openings, Chess Informant (Šahovski informator), 1966.
- Euwe, Max; Hooper, David (1959), A Guide to Chess Endings, Dover (1976 reprint), ISBN 0-486-23332-4
- Müller, Karsten; Lamprecht, Frank (2001), Fundamental Chess Endings, Gambit Publications, ISBN 1-901983-53-6
- Nunn, John (1999), Secrets of Rook Endings, Gambit Publications, ISBN 1-901983-18-8