Informant: chess term overview

Informant

Definition

In chess, “Informant” most commonly refers to two closely related ideas:

Chess Informant: the renowned Belgrade-based periodical (Šahovski Informator, founded in 1966) that standardized language‑neutral chess annotation symbols, compiled top grandmaster games, and introduced the ECO opening code system.
Informant symbols: the internationally recognized set of pictograms and signs (e.g., !, ??, ±, ∓, =, ∞) used to assess move quality and position evaluation without words. In PGN these are encoded as NAGs (Numeric Annotation Glyphs), such as $1 for “!” and $2 for “?”.

Because of this dual meaning, players use “Informant” to describe both the publication itself and the standardized annotation language it popularized. See also: Annotation, Annotation symbols, ECO.

Origins and history

Chess Informant (Šahovski Informator) was founded in Belgrade in 1966 by grandmaster Aleksandar Matanović and publisher Milivoje Molerović. Its mission: collect the world’s best recent games, expertly annotate them using symbols rather than prose, and classify opening theory. This editorial model created a universal “iconic language” that any chess player could read, regardless of native tongue.

The series quickly became indispensable for opening theory, novelties, and model games. Many top grandmasters of the pre‑internet era called it essential reading; Bobby Fischer famously dubbed it “the bible of chess.” The Chess Informant team also helped codify the ECO (Encyclopaedia of Chess Openings) A00–E99 taxonomy, a system that remains the backbone of opening classification today. Over decades and well over one hundred volumes, Informant has chronicled theoretical trends, brilliancies, and novelties (“N” or “TN”).

How “Informant” is used in chess

Annotation language: Authors and coaches mark moves with quality symbols (!, !!, !?, ?!, ?, ??) and evaluate positions with Informant evaluation signs (=, ∞, ⩲/⩱, ±/∓, +−/−+). Example: “15. e5! ±” indicates a strong move giving White a clear advantage.
Opening preparation: Players index lines by ECO codes (e.g., B90 for the Najdorf) and flag new ideas with “N” or “TN” (theoretical novelty). This aligns reports across databases, books, and software.
Databases and engines: Modern tools map Informant symbols to NAGs in PGN (e.g., $1 = “!”, $2 = “?”, $3 = “!!”, $4 = “??”, $5 = “!?”, $6 = “?!”). Viewers render the symbols while engines add numeric evals (CP, Eval) and suggested Best move.
Training: Informant‑style annotations let you skim many high‑level games quickly while still absorbing the critical assessments and plans—ideal for repertoire building and pattern recognition.

Informant symbols at a glance

Move quality: ! (good), !! (brilliant), !? (interesting), ?! (dubious), ? (mistake), ?? (blunder).
Positional evaluation:
- = equal
- ∞ unclear
- ⩲ White is slightly better; ⩱ Black is slightly better
- ± White has a clear advantage; ∓ Black has a clear advantage
- +− White is winning; −+ Black is winning
Other common pictograms (worded in prose when symbols vary by software): “with initiative,” “with attack,” “time trouble,” “only move,” “better is…,” “zugzwang,” “compensation,” “counterplay.”

Note: exact iconography can vary across editions and GUIs, but the meanings are standard. In PGN, these appear as NAG codes (e.g., $1, $2, $5), which your viewer translates into the Informant glyphs.

Strategic and historical significance

Standardization: Informant unified how the chess world communicates evaluations, enabling cross‑language study of complex games and opening theory.
Opening theory and ECO: The ECO scheme (A00–E99) is still the lingua franca of opening preparation, database searches, and repertoire management.
Pre‑internet bridge: Before engines and online databases, Informant volumes curated the cutting edge of theory and novelties, shaping how professionals prepared.
Modern synergy: Today, Informant symbols complement engine output, pairing human‑readable judgments with numeric evals for better practical understanding. See: Engine, Theory, Prepared variation.

Example: an Informant-style snippet

Below is a short illustrative line in the Giuoco Piano showing how Informant symbols might appear in notes. Imagine a typical Italian Game middlegame where White plays a timely central break to seize the initiative:

Sample commentary: “10. Ba3 N! (a novelty) aiming at c5 pressure. 15. d5! ± creates a powerful space advantage and long‑term outposts; 15…Ne7?! allows White to keep the bind.”

Play through the moves:

Informant-style reading:
• 10. Ba3 N (novelty)
• 15. d5! ± (strong break granting White a clear edge)
• 15…Ne7?! (dubious; Black drifts into a cramped stance)

Even without prose, the symbols convey that White’s central break was powerful and Black’s reaction was suboptimal. See related ideas: Central break, Space advantage, Initiative.

Common pitfalls and practical tips

Don’t overuse !! or ??: Reserve them for genuinely decisive moments; otherwise the annotation loses meaning.
Differentiate move quality vs. evaluation: “!” assesses a move; “±” assesses the resulting position.
Be consistent with NAGs: When creating PGN, add NAGs ($1 = !, $2 = ?, $3 = !!, $4 = ??, $5 = !?, $6 = ?!) so viewers render Informant symbols correctly.
Pair symbols with short reasons: Symbols are fast; a brief note (“opens the e‑file,” “wins a tempo”) boosts clarity and training value.
Check with engines, think like a human: Combine modern evals with Informant signs to balance objectivity and practical understanding. See: Practical chances.

Interesting facts and anecdotes

“Bible of chess”: Bobby Fischer famously praised Chess Informant this way, reflecting its authority before the database era.
Grandmaster contributors: Generations of top players, including world champions, have annotated games for Informant, making each volume a snapshot of elite thinking.
ECO influence: Informant helped cement A00–E99 codes. For instance, the Dragon Variation of the Sicilian is classed B70–B79; the Ruy Lopez’s main lines fall under C60–C99.
From print to digital: While born as a thick anthology, Informant’s content and symbols now permeate databases, GUIs, and training apps via PGN/NAG standards.

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