Conversation so far:
Where did Joe McGinnity begin as a professional baseball player?
George Pinkney saw McGinnity pitch, and contacted Brooklyn owner Charles Ebbets to recommend he sign McGinnity.
How did Joe McGinnity evolve career-wise ?
Joe McGinnity developed an unorthodox pitching delivery and slow pitching speed.

Question: Where did he play?
Self-contained rewrite: Where did Joe McGinnity play professional baseball?