<Table> <Tr> <Td> Bats: Left </Td> <Td> Throws: Left </Td> </Tr> </Table> <Tr> <Td> Bats: Left </Td> <Td> Throws: Left </Td> </Tr> <P> Stephen Louis Dalkowski Jr. (born June 3, 1939), nicknamed Dalko, is an American retired left - handed pitcher . He is sometimes called the fastest pitcher in baseball history and had a fastball that probably exceeded 100 mph (160 km / h). Some experts believed it went as fast as 125 mph (201 km / h), others that his pitches traveled at 120 mph (190 km / h) or less . As no radar gun or other device was available at games to measure the speed of his pitches precisely, the actual top speed of his pitches remains unknown . Regardless of its actual speed, his fastball earned him the nickname "White Lightning". Such was his reputation that despite never reaching the major leagues, and finishing his minor league years in class - B ball, the 1966 Sporting News item about the end of his career was headlined "LIVING LEGEND RELEASED ." </P> <P> Dalkowski was also famous for his unpredictable performance and inability to control his pitches . His alcoholism and violent behavior off the field caused him problems during his career and after his retirement . After he retired from baseball, he spent many years as an alcoholic, making a meager living as a manual laborer . He recovered in the 1990s, but his alcoholism has left him with dementia and he has difficulty remembering his life after the mid-1960s . </P>

Who is the hardest throwing pitcher of all time