Give the player id of the player who was at the non-striker end for the most number of balls in the match 501219.
most number of balls refers to max(Ball_Id); match 501219 refers to Match_Id = 501219;
player id also refers to non_striker or ball_id
SELECT Ball_Id FROM Ball_by_Ball WHERE Non_Striker = Ball_Id ORDER BY Ball_Id DESC LIMIT 1