William Henry Stein
- Bats Unknown, Throws Left
- Debut July 22, 1890
- Final Game July 22, 1890
- Born April 9, 1868 in Telford, PA USA
- Died November 11, 1945 in Philadelphia, PA USA
Nothing else was known about him and for a long time, he was simply listed as "Stein" in many reference sources, and also sometimes as Harry C. Stine. It was researcher Richard Malatzky who was able to confirm his name and identify a likely candidate, but without formal proof. The results of his research were published on historian John Thorn's blog in 2016 and, incredibly, a descendant of the pitcher, his great grandson, ran across the article five years later, after Malatzky had passed away. He was able to confirm that his ancestor was indeed the pitcher. The information dug up by the researcher matched what the family knew about about Stein. In fact, his granddaughter had always thought her grandpa was lying when he said he had pitched in the major leagues, but it was known that he had played baseball and photographs of him in a minor league uniform had been passed down. The two stories meshed perfectly to confirm his identity.
- "William Stein Found", in Bill Carle, ed.: Biographical Research Committee Report, SABR, May-June 2021, p. 1.