How many movies have Ng Yat-Siu and Yu-chai Chu collaborated on?

They have worked on 3 movies together! Their first movie together was Wong Fei-hung: The Whip That Smacks the Candle (1949) and was their highest rated movie together. They have not worked together since Huang Fei-hong's Battle at Liu-hua Bridge (1950). They are most known for their drama films together.