next move, both f7 and b7 will be under attack. 7. Qb3 Qe7 (diagram) Black's only good move. Almost all of Black's moves lead to checkmate , for example 7. ... Nc6 8. Bxf7 Ke7 9. Qe6#. 7. ... Qd7 loses the rook to 8. Qxb7 followed by 9. Qxa8. Notice