Sideline
A less common alternative to the main line within a given opening or variation.
Sidelines are played less often than the main line, sometimes because they are considered objectively weaker and sometimes simply because they are less explored, making them useful as a practical surprise weapon.
Etymology
Sideline is a general English word borrowed into chess usage; Etymonline records it from 1768 in the sense of a line extending along or attached to the side of anything, with the sports boundary-line sense by 1862, the railway sense of a line extending from a main line in 1890, and the figurative sense of a position removed from active participation in 1934. Wiktionary's entry gives no etymology and lists no chess sense at all, with its earliest citation dated 1809. The chess application is a straightforward extension of the railway metaphor that also underlies main line: a sideline is a branch that departs from the main line of an opening variation. Notably, the Wikipedia glossary of chess has no entry for sideline, which indicates it is informal usage rather than a codified term. No source located in this session documents a first chess use or a coinage date.
First documented: n.a. — n.a. for the chess sense; the general English word is attested from 1768 per Etymonline
Translations
Translations for this term haven't been added yet.