user: Question: Where did the team play when the home team score was 12.9 (81)?
Columns: ['Home team', 'Home team score', 'Away team', 'Away team score', 'Ground', 'Crowd', 'Date']
Types: ['text', 'text', 'text', 'text', 'text', 'real', 'text']
Sample row: ['St Kilda', '16.13 (109)', 'Melbourne', '5.11 (41)', 'Colonial Stadium', 13814.0, 'Friday, 15 February']
SQL:

assistant: SELECT "Ground" FROM "Table" WHERE "Home team score" = '12.9 (81)';