The Knickerbocker Rules are a set of baseball rules formalized by William R. Wheaton and William H. Tucker of the Knickerbocker Base Ball Club in 1845. They have previously been considered to be the basis for the rules of the modern game, although this is disputed. The rules are informally known as the "New York style" of baseball, as opposed to other variants such as the "Massachusetts Game."
Modern scholarship has cast doubt on the originality of these rules, as information has come to light about the New York clubs that predated the Knickerbockers, in particular the rules devised by William R. Wheaton for the Gotham Club in 1837. Baseball historian Jeffrey Kittel has concluded that none of the Knickerbocker Rules of 1845 was original, with the possible exception of three-out innings.
Several of the rules are still around in some form today, while others are in direct contrast to current rules. A few of the more interesting examples are shown below. The list as presented, except for the commentary, is taken directly from the "Rules" as published in the 1860 Beadle's Dime Base Ball Player, edited by Henry Chadwick (website below):
4th. The bases shall be from "home" to second base, forty-two paces; from first to third base, forty-two paces, equidistant.
8th. The game to consist of twenty-one counts, or aces; but at the conclusion an equal number of hands must be played.
9th. The ball must be pitched, not thrown, for the bat.
10th. A ball knocked out of the field, or outside the range of the first and third base, is foul.
11th. Three balls being struck at and missed and the last one caught, is a hand-out; if not caught it is considered fair, and the striker bound to run.
12th. If a ball be struck, or tipped, and caught, either flying or on the first bound, it is a hand out.
13th. A player running the bases shall be out, if the ball is in the hands of an adversary on the base, or the runner is touched with it before he makes his base; it being understood, however, that in no instance is a ball to be thrown at him.