In beer pong: The designated air-ball catcher, bounce swatter, blower/fingerer. Designated to avoid confusion between teammates when a situation stated above occurs.
Teammate 1: "alright man you're the ballerist this round!"
Teammate 2: "i got this sh*t!!"
In a game of beer pong: "Stop fucking texting! you're the ballerist, pay attention, catch the fucking ball"