user: Question: What is the largest Grid with a Driver of Piers Courage?
Columns: ['Driver', 'Constructor', 'Laps', 'Time/Retired', 'Grid']
Types: ['text', 'text', 'real', 'text', 'real']
Sample row: ['Bruce McLaren', 'McLaren - Ford', 28.0, '1:40:02.1', 6.0]
SQL:

assistant: SELECT MAX("Grid") FROM "Table" WHERE "Driver" = 'Piers Courage';