Duncan Tappy ขับในรอบใด?ไม่จำเป็นต้องใช้โต๊ะทั้งหมด
What round does Duncan Tappy drive in?It is not neccessary to use all the tables.
 table_23293785_3:  (sf_round [ INTEGER ] driver [ VARCHAR) ]
SELECT MAX(sf_round) FROM table_23293785_3 WHERE driver = "Duncan Tappy"