Fortress
A defensive setup in which a side with fewer or weaker pieces creates an impenetrable position, securing a draw despite material disadvantage.
A fortress relies on the defending king and pieces occupying a configuration the stronger side cannot break without giving up the very material advantage they are trying to convert.
Etymology
Fortress entered English in the early 14th century from Old French forteresse. The chess sense is a straightforward military metaphor for an impenetrable position which, if obtained by the side with a material disadvantage, may result in a draw because the stronger side cannot make progress. No source consulted names a coiner, but the earliest dated examples cited run from Lolli (1763) and Kling & Horwitz (1851) through a 1912 W. E. Rudolph study in La Stratégie, and Emanuel Lasker–Edward Lasker, New York 1924, described as a “new endgame fortress.”
First documented: 1763 — Earliest dated fortress-type endgame position cited: Lolli, 1763
Translations
Translations for this term haven't been added yet.