TN (Theoretical Novelty)
A casual abbreviation used in game annotations and opening literature to flag a move as a theoretical novelty, a new idea in a previously analyzed position.
Annotators typically mark a move with "TN" or "N" in database comments to indicate it had not previously appeared in that exact position in the available game record.
Etymology
TN is a printer's and database abbreviation, not a word: it stands for theoretical novelty, a move or idea in the opening that has not been played before and is therefore new to established theory. Wikipedia's Glossary of chess carries the entry under theoretical novelty and records both abbreviations, TN and N. Chess.com's definition agrees: a new opening move or idea previously unknown to chess theory, abbreviated N or TN in chess literature and databases, and it illustrates the concept with Bobby Fischer's 11...Nh5 in game three of the 1972 World Championship match against Boris Spassky, a move never played before. Compact symbol systems of this kind are associated with the Belgrade publisher Chess Informant, founded in 1966 by Aleksandar Matanovic and Milivoje Molerovic, which developed a language-independent system of symbols and codes explained in ten languages in each volume; the Chess Informant Wikipedia article, however, does not itself mention N or TN, so that link should not be asserted as sourced fact.
First documented: n.a. — n.a. - no dated first use of the abbreviation found
Translations
Translations for this term haven't been added yet.