This is real short but it's a favorite moment from a favorite TV program — The Dick Van Dyke Show, of course. Mary Tyler Moore was supposed to make an impossible pool shot and they were going to do it by cutting to a close-up of the table as a professional pool player sank three balls with one shot. Then they would cut back to Dick Van Dyke and Mary to button the scene. But to the amazement of all, Mary included, she made the shot. Notice how expertly both actors remain in character…