According to many sports enthusiasts, the word “southpaw” began to be used to refer to lefthanders in the late 19th Century. Some believe that the sports columnist Finley Peter Dunne coined the word. “Southpaw” comes to us from the world of baseball.
This popular American game is usually played in the summer; professional games are played either in the afternoons or in the evenings. In most stadiums, the “home plate” or the batter’s box is placed in such a manner that it faces east. This is done to ensure that the batter doesn’t have the afternoon or evening sun in his eyes when he bats.
The pitcher throws the ball facing west. This being the case, when a left-handed pitcher winds up for his delivery, his throwing arm is facing south. Hence the term “southpaw”. The “paw” refers to the hand of the pitcher.