CREATE TABLE table_1137702_3 (grand_prix VARCHAR(255), winning_constructor VARCHAR(255), pole_position VARCHAR(255))
How many Grand Prix were the winning constructor Benetton - Ford and the pole position was Michael Schumacher?
    
SQL: SELECT COUNT(grand_prix) FROM table_1137702_3 WHERE winning_constructor = "Benetton - Ford" AND pole_position = "Michael Schumacher"