The Case Of The Unlucky Gambler is a Sherlock Holmes movie from 1955.
Starring Ronald Howard and H. Marion Crawford as Holmes and Watson respectively.
A young boy comes to Holmes for help as his father has gone missing.
Just from the conversation, he works out that he’s a gambler in debt and on the run.
They track him down and, in front of the boy, cover for his shortcomings, giving him a chance to get his life back on track.