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. Typical moves that receive double question marks are those that overlook a tactic that wins substantial , overlook a checkmate, or miss a winning move after a severe mistake by the opponent. A "??"-worthy move may result in an immediately lost position, turn a won position into a draw, lose an important piece or otherwise severely worsen the player's position.
Blunders occur at all levels of play. In fact, one of the most infamous blunders in chess history occurred in the twenty-third game of the 1892 World Chess Championship, which famously came to an abrupt and unexpected end when Mikhail Chigorin hung a mate in two in an otherwise completely winning position.
<span class="anchor" id="?"></span><span class="anchor" id="mistake"></span>? (Mistake)
A single question mark "?" indicates that the annotator thinks that the move is a mistake and should not have been played.
<span class="anchor" id="!"></span><span class="anchor" id="Good move"></span><span class="anchor" id="Good"></span>! (Good move)
An exclamation point "!" indicates a good move, especially one that is surprising or requires particular skill.
The symbol may also be interpreted as "best move". Annotators are usually somewhat conservative with the use of this symbol; for example, it is not usually awarded to obvious moves that capture material or deliver checkmate.
Reasons for awarding the symbol vary greatly between annotators; among them are strong , good psychological opening choices, well-timed breakthroughs, sound sacrifices, moves that set traps in lost positions, moves that avoid such traps, moves that punish mistakes well, sequential moves during brilliancies, and being the only good move that maintains the player's position.
Chess.com and other online chess servers use the symbol more extensively for a "great" move, which is often defined as the only move that keeps an advantage for the player in the specific position.
<span class="anchor" id="!!"></span><span class="anchor" id="‼"></span><span class="anchor" id="Brilliant move"></span><span class="anchor" id="Brilliant"></span>!! (Brilliant move)
The double exclamation point "!!" is used for outstanding
Unusual symbols
The majority of chess writers and editors consider symbols more than two characters long unnecessary. However a few writers have used three or more exclamation points ("!!!") for an exceptionally brilliant move, three or more question marks ("???") for an exceptionally bad blunder, or unusual combinations of exclamation points and question marks ("!?!", "?!?" etc.) for particularly unusual, spectacular, controversial or unsound moves.
For example, when annotating Rotlewi–Rubinstein 1907, Hans Kmoch awarded Rubinstein's 22...Rxc3 three exclamation points. Annotators have also awarded the final move of Levitsky–Marshall 1912 (the "Gold Coins Game"), 23...Qg3 the "!!!" symbol.
An exceptionally bad blunder which has sometimes been awarded three or more question marks occurred in Deep Fritz–Kramnik 2006, when Kramnik played 34...Qe3, overlooking a mate in one with 35.Qh7#.
Parentheses
Sometimes annotation symbols are put in parentheses, e.g. "(?)", "(!)". Different writers have used these in different ways.
Ludek Pachman used "(?)" to indicate a move that he considered inferior but that he did not wish to comment on further; Simon Webb used it to indicate a move that is objectively sound, but was in his opinion a poor psychological choice; and Robert Hübner (see below) used it to indicate a move that is inaccurate and makes the player's task more difficult.
When put in parentheses, "(!)" usually indicates a subtlety which demonstrates the player's skill rather than a spectacular move.
Formalized definitions
Some writers choose to take a less subjective or more formalized approach to these symbols.
Nunn's 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:
{| class="wikitable"
|- style="vertical-align:bottom;"
! Symbol
!style="text-align:left;"| Meaning
|- style="vertical-align:top;"
|style="text-align:center;"| !
| The only move that maintains the current evaluation of the position: If the position is theoretically drawn, this is the only move that does not lose; if the position is theoretically won, this is the only move that 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.
|- style="vertical-align:top;"
|style="text-align:center;"| !!
| A particularly difficult-to-find "!" move
|- style="vertical-align:top;"
|style="text-align:center;"| ?
| A move that 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.
|- style="vertical-align:top;"
|style="text-align:center;"| ??
| An obviously bad "?" move
|- style="vertical-align:top;"
|style="text-align:center;"| !?
| A move that makes the opponent's task harder or one's own task easier; for example, in a theoretically lost position, a move that forces the opponent to find several "!" moves in order to win
|- style="vertical-align:top;"
|style="text-align:center;"| ?!
| A move that makes the opponent's task easier or one's own task harder; for example, in a theoretically won position, a move that requires several subsequent "!" moves in order to win
|}
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:
{| class="wikitable"
|- style="vertical-align:bottom;"
! Symbol
! style="text-align:left;" | Meaning
|- style="vertical-align:top;"
| style="text-align:center;" | ?
| A move that turns a winning position into a drawn position, or a drawn position into a lost position.
|- style="vertical-align:top;"
| style="text-align:center;" | ??
| A move that turns a winning position into a lost position.
|- style="vertical-align:top;"
| style="text-align:center;" | (?)
| An inaccuracy; a move that significantly increases the difficulty of the player's task.
|}
Chess composition
When the solution to a certain chess problem is given, there are also some conventions that have become a common practice:
{| class="wikitable"
|- style="vertical-align:bottom;"
! Symbol
!style="text-align:left;"| Meaning
|- style="vertical-align:top;"
|style="text-align:center;"| !
| A move is marked with at least one "!"
|- style="vertical-align:top;"
|style="text-align:center;"| ?
| A move
|- style="vertical-align:top;"
|style="text-align:center;"| !
| A refutation to a try move
|- style="vertical-align:top;"
|style="text-align:center;"| ?
| When is a part of the thematic content of a problem, avoided duals (if listed) are marked with "?"
|}
<span class="anchor" id="Position"></span><span class="anchor" id="Pos eval"></span><span class="anchor" id="Pos"></span> Positions
These symbols indicate the strategic balance of the game position:
{| class="wikitable"
|- style="vertical-align:bottom;"
! CP437
! Unicode
!style="text-align:left;"| In brief
!style="text-align:left;"| Meaning
|- style="vertical-align:top;"
|style="text-align:center;"| =
|
| Equal
| Even position: White and Black have more or less equal chances.
|}
<span class="anchor" id="Others"></span> 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.
Move-related
{| class="wikitable"
|- style="vertical-align:bottom;"
! Symbol
!style="text-align:left;"| In brief
!style="text-align:left;"| Meaning
|- style="vertical-align:top;"
|style="text-align:center;"|
| Better
| A better move than the one played