The New York Times Archives are a great source of game reporting plus box scores. If you're specifically interested in games that Matty pitched you may also find useful Christy Mathewson: A Game-by-Game Profile of a Legendary Pitcher by Ronald Mayer. It does not provide box scores but does give a synopsis of each big league game he pitched. The book was published in 1993 but re-issued later by McFarland Publishing. I got my copy from Amazon.
|