sentence: milton arnold '' mickey '' haefner ( october 9 , 1912 -- january 3 , 1995 ) was an american knuckleball - throwing left-handed pitcher in major league baseball who played eight seasons from 1943 to 1950 , six and a half of them with the washington senators ( 1943 -- 49 ) , later joining the chicago white sox ( 1949 -- 50 ) and the boston braves ( 1950 ) .