southpaw (n.)

"lefthander," 1885, originally baseball slang, of pitchers, often said to have been coined by Finley Peter Dunne ("Mr. Dooley"), Chicago sports journalist and humorist, in the days when, it is said, baseball diamonds regularly were laid out with home plate to the west. But south paw "a person's left hand" is attested from 1848 in the slang of pugilism.