The Knickerbocker Rules, established in 1845, provided a foundational framework for baseball, but the game underwent significant transformations through subsequent rule changes. Many of these modifications addressed ambiguities, improved fairness, or adapted to evolving playing styles. Examining these changes reveals a clear path from the informal "New York style" of baseball to the structured sport played today, highlighting how the game continuously
refined itself to enhance competition and spectator experience.
From "Aces" to Innings: Defining Game Length
One of the most significant early changes involved how a game's length was determined. The original Knickerbocker Rule 8 stated, "The game to consist of twenty-one counts, or aces; but at the conclusion an equal number of hands must be played." This meant the first team to score 21 "aces" (what we now call runs) would win, provided both teams had an equal number of turns at bat. This system, borrowing terminology from card games, could lead to highly variable game lengths. For example, a game could theoretically end after a single inning if one team scored 21 runs.
This approach proved problematic as competitive play increased. An 1856 game between the Knickerbockers and the Empire club, which ended in a tie after both teams scored 21 runs over eight innings, underscored the need for a more definitive game length. The 1857 baseball convention addressed this by introducing the concept of innings, a term borrowed from cricket. While the Knickerbockers initially advocated for seven-inning games, and a proposal for twelve innings was considered, the convention ultimately settled on the nine-inning standard that remains in place today. This change, along with a provision to declare a winner if a game was suspended after five innings, effectively eliminated the possibility of draws.
Pitching Evolution: From Underhand to Overhand and Beyond
The method of pitching also saw substantial evolution. Knickerbocker Rule 9 specified, "The ball must be pitched, not thrown, for the bat," requiring an underhand delivery. This style was akin to pitching a horseshoe, emphasizing placement rather than velocity. Overhand pitching, a staple of modern baseball, was not permitted until 1884, and even then, the transition was gradual, with pitchers slowly increasing speed and developing movement within the underhand constraints before fully embracing overhand deliveries. Early rules also lacked a precise location for the pitcher, which was later standardized.
Furthermore, the concepts of "balls" and "strikes" as we know them were absent in the original Knickerbocker Rules. Rule 11 outlined the three-strike rule for an out, but it made no reference to a strike zone or called strikes. Called strikes were introduced in 1858 as a penalty for batters who persistently refused to swing after a warning. Similarly, "balls" were introduced in 1863 as a penalty for pitchers who consistently threw wide of the plate or delivered pitches intended to intimidate rather than be hit. The number of balls required for a walk varied before being fixed at four in 1889, and the strike zone itself wasn't formally defined until 1887, leaving judgment to the umpire prior to that.
Fielding and Baserunning: Safety and Strategy
Early fielding rules also differed significantly. Knickerbocker Rule 12 stated that a ball caught "either flying or on the first bound" resulted in an out. This meant that catching a fair ball after one bounce was an out, a practice that continued until 1865. Catching a foul ball on the first bounce remained an out until 1883. This rule was practical in an era when gloves were not used, making catches on the bounce more feasible. The most impactful change for player safety and baserunning strategy was Rule 13, which prohibited "soaking" or "plugging"—putting out a runner by hitting them with a thrown ball. Instead, a runner was out if an adversary held the ball on the base or touched the runner with it before they reached the base. This was a crucial departure from earlier, more dangerous forms of the game and laid the groundwork for modern tagging and force-out rules.
