user: Question: WHAT IS THE RIDER WITH A 21 GRID?
Columns: ['Rider', 'Manufacturer', 'Laps', 'Time/Retired', 'Grid']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['Dani Pedrosa', 'Honda', '24', '40:46.694', '7']
SQL:

assistant: SELECT "Rider" FROM "Table" WHERE "Grid" = '21';