The Kid From Left Field is a 1953 baseball film that features an excellent cast (Dan Dailey, Anne Bancroft, Lloyd Bridges) and deft direction from Harmon Jones.
Dailey portrays an ex-ballplayer who now is employed as a peanut vendor at the stadium where he once was a hero. Caught one too many times sneaking his son into the stadium, Coop (Dailey) is fired and the future, already looking bleak, takes a turn for the worse.
The son however, charms the ballclub owner's niece (Bancroft), and manages not only to land a job as batboy, he also gets his father his job back, as well as inspiring the previously hapless ball club to unprecedented heights.
Director Jones and Dailey had teamed up a year earlier in another baseball film, The Pride Of St. Louis.