Table: 1930 - 31 fa cup
Question:  What is the most common winning margin for teams in the 1930-31 FA Cup?
Step 1 (Reasoning, Other Commonsense Reasoning): winning margin
Step 2 (Reasoning, Arithmetic): -, score
Step 3 (Operation, Grouping): score
Step 4 (Reasoning, Aggregating): MAX, most common
Answer: 2