'backstopping' originates from modern English, formed by adding the gerund/agent suffix '-ing' to the compound noun 'backstop' (i.e. 'backstop' + '-ing').

'backstop' originally appears in late 19th-century American English (baseball), referring to the barrier or position behind the catcher; the compound was later extended beyond sport to mean any safeguard or support, and then formed into 'backstopping' for the action or process.

Initially, 'backstop' meant 'a physical barrier or position behind a catcher in baseball'; over time it broadened to mean 'a safeguard, guarantee, or backup support,' which is the current sense used in general, financial, and organizational contexts.