"Scientific Base Ball Pitching. A Treatise on the Pitcher, Pitching, Origin and Philosophy of the Curve, Methods of Pitching and Practice" (1894) by James W. Smith is considered by many experts to be the rarest baseball book ever published. It is so rare, in fact, that it does not even appear in "The Guide To Baseball Literature," by Anton Grobani, a seminal work on the literature of baseball with over 2,000 entries. This is the first and only copy which we know of. The preface explains the author's motivation for writing the book, namely, to provide various pitching methods and the theory and practice of the curve ball. The book exhibits unusual string binding as well as a light vertical bend at the center. Also, the name and address of the reader have been neatly penned on the cover. The book is entirely intact and in exceptionally good condition considering its 125-year vintage. Displays engaging cover graphics, while the interior features an assortment of visuals and methods for throwing various curves, the "slow ball," and the "zigzag ball."