History has a way of repeating itself. The modern era of sabermetrics has deep roots in the work of Bill James and his discovery of the close relationship between the number of wins a team accumulates over the course of a season and the ratio of runs scored to runs allowed. This discovery and the new statistics developed as a result of this work allowed the individual contributions of a player to be more accurately measured. The advanced analytics of today have developed as a result of sportswriters with a background in statistics finding new and better ways to measure player performance. History has a way of repeating itself.
According to Wikipedia, "The first team to play baseball under modern rules were the New York Knickerbockers." The club is credited with formation in 1845 and writing a set of rules that dictated how the game was to be played. Interestingly enough, up until this point in time you could actually get a runner out by hitting them with the ball as they ran the bases. The Knickerbockers were beaten in the first recorded game on June 19, 1846, losing to the New York Club by a score of 23 to 1.
The first newspaper reporting of results of a baseball game with a box score is commonly thought to have occurred in 1853. Further work has uncovered reporting of baseball game with a box score in 1845 between the New York Club and the Brooklyn Club, which occurred prior to the official first game in 1846, but it cannot be confirmed if the games were played by the same rules. The reporting of statistics in the very first box scores included only batter runs and put outs, similar to the way reporting was done on cricket. The concept of collecting individual batter hits had not been used in the very first games played and would not be seen until 1859.
Before Bill James, there was a journalist named Henry Chadwick. Chadwick was a sportswriter who also dabbled as an amateur statistician and is credited with presenting the very first modern box score in The New York Clipper in 1859. This box score included runs, hits, put outs, assists and errors for each team's players, a line score and the introduction of the strike-out (complete with using a 'K' on the scorecard). The very first collection and reporting of modern statistics from a baseball game was done by a sportswriter that was versed in the basics of statistics. Sources can neither confirm or deny that this was done over a freshly toasted fruit pastry in the salon of his parent's home.
The very first batting champions were named by The New York Clipper, which used the statistic of hits per game to determine the winner. Chadwick was a proponent of this early 'batting average' statistic and he also created the precursor to today's statistic of slugging percentage, which took total bases and divided them by the total number of games played. These were the very first attempts at using some type of weighted average and are the very first baseball statistics .
During the 1860s, it became quite apparent that using number of games played as the denominator for batting average and slugging percentage gave unfair advantage to quality offensive teams that provided more at-bats for their players. The denominator of games played was replaced by number of at-bats, but was not until 1874 that the modern 'batting average' statistic was reported by a Boston newspaper and it became an officially computed statistic for the National League in 1876. Fun fact, since the invention of the modern batting average, there has been the invention of the telephone, escalator, motion picture, vaccine, game of basketball, cash register, fountain pen, paper clip, radio, x-ray and zipper.
It can be seen that the development and transformation of the early statistics in baseball is very similar to the evolution of modern sabermetrics. The introduction of the modern box score provided a method to categorize and record individual player contributions over the course of the game, which led to the very first calculations of a 'batting average'. As the game progressed, sportswriters and other proponents of the game began to see fundamental weaknesses of the first batter computations and adjustments were made in order to make the batter statistics more representative of the actual contribution by an individual player to the team. Updating the original batting average statistic by using at bats for the denominator instead of games played was an historic moment, as the modern batting average became the very first advanced statistic.
The early history of baseball was shaped by sportswriters and statisticians as a result of a fundamental understanding of how the game was progressing. New statistics were identified that better allowed the measurement of individual player contributions to team wins. It can be argued that the field of sabermetrics today is a continuation of a practice that is as old as the game itself. "Mom's basement" could be a lot closer to the dirt than originally thought.