One who balls like a pro. If someone is baller at absolutely anything, he/she has the right to call themselves a pro baller. A pro baller tends to be "the shit".
Jon: "Nirman makes everything hilarious!"
Frank: "Yeah, and he a beast on the court."
Jon: "What a pro baller."
The mess left in your bathroom after a guest uses it to shower and leaves it a mess with dirty clothes and wet towels on the floor and their personal grooming crap on the sink.