Ewing compiled a 53–63 career record in 129 appearances, with a 3.68 earned run average and 525 strikeouts. In 1891 he led the National League in ERA (a retroactive ranking; ERA was not tabulated in that era) while playing for New York.
Ewing was used as a first base umpire in an American Association game on August 15, 1889.[1]
He was the brother of Hall of Famecatcher and infielderBuck Ewing. The brothers played on the same team for two seasons, and Buck managed the 1890 Giants team for which John pitched.