user: ### NOW ANSWER:
Question: What is the grid for Dirk Heidolf?
Columns: ['Rider', 'Manufacturer', 'Laps', 'Time/Retired', 'Grid']
Types: ['text', 'text', 'real', 'text', 'real']
Sample row: ['Álvaro Bautista', 'Aprilia', 21.0, '40:18.605', 1.0]
SQL:

assistant: SELECT SUM("Grid") FROM "Table" WHERE "Rider" = 'Dirk Heidolf';