All Tennis Players How Many Grand Slams Has Roscoe Tanner Won? Leonard Roscoe Tanner (born October 15, 1951) is a retired American tennis player.Roscoe Tanner has won 1 Grand Slam. FacebookTwitterEmail How Many Grand Slams Has Madison Keys Won? How Many Grand Slams Has Jannik Sinner Won? How Many Majors Has John Isner Won?
