imaginary runner

Also called ghost runner, in·vis·i·ble run·ner [in-viz-uh-buhl ruhn-er], /ɪnˈvɪz ə bəl ˈrʌn ər/, in·vis·i·ble man [in-viz-uh-buhl man] /ɪnˈvɪz ə bəl ˈmæn/ . a provision of informal, usually childhood play in which a deficit of players allows a base runner to return to home plate for their at-bat while being replaced on base by an imaginary player, the advancement of whom is governed by various rules agreed to beforehand: also utilized in stickball, kickball, and other games related to baseball.