user: Question: How many winning drivers in the Kraco Twin 125 (R2) race were there?
Columns: ['Rd', 'Name', 'Pole Position', 'Fastest Lap', 'Winning driver', 'Winning team', 'Report']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, 'Kraco Car Stereo 200', 'Bobby Unser', 'Unknown', 'Johnny Rutherford', 'Chaparral', 'Report']
SQL:

assistant: SELECT COUNT("Winning driver") FROM "Table" WHERE "Name" = 'Kraco Twin 125 (R2)';