user: Question: Who was the opponent when Richmond played as the home team?
Columns: ['Home team', 'Home team score', 'Away team', 'Away team score', 'Venue', 'Crowd', 'Date']
Types: ['text', 'text', 'text', 'text', 'text', 'real', 'text']
Sample row: ['Richmond', '9.10 (64)', 'South Melbourne', '20.10 (130)', 'Punt Road Oval', 15000.0, '3 August 1963']
SQL:

assistant: SELECT "Away team" FROM "Table" WHERE "Home team" = 'Richmond';