judgment call


noun

Sports. an observational ruling by a referee or umpire that is necessarily subjective because of the disputable nature of the play in question, and one that may be appealed but not protested, as opposed to a matter of official rule interpretation: Balks and close plays at first are of course judgment calls, and umpires are human.
any subjective or debatable determination; personal opinion or interpretation.

Origin of judgment call

First recorded in 1840–50