user: Question: What is the smallest number of extra points for a Left halfback?
Columns: ['Player', 'Position', 'Starter', 'Touchdowns', 'Extra points', 'Field goals', 'Points']
Types: ['text', 'text', 'text', 'real', 'real', 'real', 'real']
Sample row: ['Webber', 'Left halfback', 'Yes', 1.0, 2.0, 0.0, 7.0]
SQL:

assistant: SELECT MIN("Extra points") FROM "Table" WHERE "Position" = 'Left halfback';