Unknown (NN) – Chess term

Unknown

Definition

In chess literature and databases the word “Unknown” (often abbreviated as NN, from the Latin Nomen Nescio, “I do not know the name”) is a placeholder used whenever some piece of information about a game is missing or unrecorded—most commonly the name of one of the players, the event, the opening variation, or even the exact date. It therefore does not denote a strategic concept played on the board; rather, it is a bibliographic convention that signals an informational gap in the historical record.

Typical Usage

• Player name: “Morphy – Unknown, New York 1857.”
• Event: “Kasparov vs. Deep Blue, Unknown Event, 1997.”
• Opening: Databases may list “Unknown Opening” when the first moves do not yet have an ECO code or cannot be confidently classified.
• Move order: Engines occasionally annotate a novelty as “0.00/Unknown” when no prior theory exists for the position.

Strategic or Historical Significance

While “Unknown” has no direct bearing on over-the-board strategy, it is historically significant because thousands of classic games were played before systematic record-keeping became standard. The placeholder thus reminds researchers of the limits of our knowledge and often sparks investigative work by chess historians trying to uncover the real identities of forgotten masters.

Illustrative Examples

1. Morphy – Unknown, New Orleans 1858
   A dazzling miniature in which Paul Morphy sacrifices both rooks and a bishop to force mate. The defeated amateur’s name was never recorded, so all modern databases list the opponent simply as “Unknown” or “NN.”

   
   

2. “Immortal Zugzwang Game” – Opponent Unknown
   In some older monographs the celebrated 1923 game Böök – Unknown (also published as “Böök – NN”) is hailed as a classic example of zugzwang in the endgame. Later research eventually identified the opponent as Ragnar Krogius, illustrating how an “Unknown” tag can evolve into a known fact.

Interesting Facts & Anecdotes

• Why “NN”? The abbreviation comes from legal Latin, where “Nomen Nescio” is written when a defendant or witness cannot be named.
• Morphy’s Casual Games: Because the American prodigy played countless informal skittles games, many adversaries were club players whose identities were never written down, leading to dozens of “Morphy – Unknown” entries.
• Database Hygiene: Modern databases such as ChessBase distinguish between the literal surname “Unknown” and the NN placeholder by assigning a special player ID (often “#0”) to avoid conflating real surnames (there are grandmasters actually named “Unknownov” or “Unokyen”!) with missing data.
• ECO “A00”: Even openings labelled “A00” are not truly “unknown.” They are simply “Irregular Openings,” but if a game’s first moves are so unusual that they do not fit anywhere else, some software will temporarily tag the opening as “Unknown.”

Summary

Whenever you encounter the word “Unknown” or the initials “NN” in a scoresheet, article, or database, read it as a blank space waiting to be filled rather than as a new piece of chess jargon. It is an invitation to historians, archivists, and the curious player to dig deeper into the game’s past and maybe—just maybe—replace “Unknown” with a real name, place, or variation.