Early baseball was a variant of bat-and-ball games in the medieval world, such as stool ball, old cat, and trap ball. Such games involved hitting, fielding, and sometimes base running, although the rules were few and flexible. During the Revolutionary War, American soldiers wrote of “playing ball,” though it’s not always clear what game they were playing. By the mid-nineteenth century, two distinct brands of baseball rivaled for supremacy. In New England, the Massachusetts Game was played on a rectangular field and employed overhand pitching. Its most compelling feature, though, was that fielders could put out a baserunner by striking him with a thrown ball. Meanwhile, the New York Game was contested on a diamond-shaped field, and the pitcher delivered the ball underhand. Although the Massachusetts Game was played regionally throughout the nineteenth century, the New York version, smartly promoted by the seasoned Knickerbockers and an enthusiastic local press, won out as the preferred form of the sport.