The Ball Is in Your Court

A literal, clearly documented image borrowed from tennis: once a player has hit the ball over the net, responsibility for the next shot passes entirely to whoever's half of the court it lands in. "Court" itself has a long pedigree, from the Latin "cohors" (an enclosed yard) through Old French, originally describing a sovereign's residence before narrowing to mean an enclosed play area. The tennis image was used occasionally from the early 19th century, but the fully figurative, everyday sense of passing responsibility to someone else only became popular around the 1960s and 70s.