user: Question: What is the average crowd size when the home side scores 8.9 (57)?
Columns: ['Home team', 'Home team score', 'Away team', 'Away team score', 'Venue', 'Crowd', 'Date']
Types: ['text', 'text', 'text', 'text', 'text', 'real', 'text']
Sample row: ['Fitzroy', '16.9 (105)', 'Geelong', '12.9 (81)', 'Brunswick Street Oval', 9000.0, '18 August 1928']
SQL:

assistant: SELECT AVG("Crowd") FROM "Table" WHERE "Home team score" = '8.9 (57)';