Sitzfleisch

Sitzfleisch is a German compound of sitzen meaning to sit and Fleisch meaning flesh, confirmed as such by the German dictionary DWDS, which also records the idioms Sitzfleisch haben and kein Sitzfleisch haben. Wikipedia's Glossary of chess glosses it as from German, sitting flesh, and defines the chess quality as the ability to sit still, that is the stamina and patience to sit through a very long game and outlast an opponent, sometimes with the implication of winning by endurance rather than brilliance. Edward Winter's Earliest Occurrences of Chess Terms gives a strikingly early English chess attestation: the Chess Monthly of December 1881, page 113, in a letter signed Philidor Jones, containing the sentence, It is Sitzfleisch that decides a game. The Oxford English Dictionary's general-English citation is later, from D. H. Lawrence in 1932, and Wiktionary's chess quotation is later still, Frank Vigor Morley's My One Contribution to Chess (Faber and Faber, 1947).

First documented: 1881 — Chess Monthly, December 1881, p. 113, letter from Philidor Jones, per Edward Winter