Henry Chadwick

"Henry Chadwick (October 5, 1824 – April 20, 1908), often called the 'father of baseball,' was a sportswriter, baseball statistician and historian. ... Chadwick edited The Beadle Baseball Player, the first baseball guide on public sale, as well as the Spalding and Reach annual guides for a number of years and in this capacity promoted the game and influenced the then-infant discipline of sports journalism. He also served on baseball rules committees and influenced the game itself. In his 1861 Beadle guide, he listed totals of games played, outs, runs, home runs, and strikeouts for hitters on prominent clubs, the first database of its kind. His goal was to provide numerical evidence to prove what players helped or hurt a team to win. ... He is credited with devising the baseball box score (which he adapted from the cricket scorecard) for reporting game events. The first box score was a grid with nine rows for players and nine columns for innings. The original box scores also created the often puzzling abbreviation for strikeout as 'K' - 'K' being the last letter of 'struck' in 'struck out.' The basic format and structure of the box score has changed little since the earliest of ones designed by Chadwick. He is also credited with devising such statistical measures as batting average and earned run average. Ironically, ERA originated not in the goal of measuring a pitcher's worth but to differentiate between runs caused by batting skill (hits) and lack of fielding skill (errors). He is also noted as believing fielding range to be a superior skill to avoiding errors."
Wikipedia

The Baseball Box Score was First Developed by Henry Chadwick
"Today I found out the baseball box score was first developed and introduced by Henry Chadwick, 'The Father of Baseball'. Chadwick also authored Baseball’s first rule book; devised the batting average and earned run average; compiled the game’s first instructional guides and player and statistical reference books, among a variety of other contributions to the game. He is also the only writer to have been elected into the Baseball Hall of Fame in the non-writers wing. ... The first thing he did was try to persuade the New York Times, who prominently reported cricket matches, to start covering baseball as well. He even offered to report the games himself, so they wouldn’t have to hire anyone for the job. Eventually, he got a job at the New York Clipper as a sportswriter in 1857. From there, he set about trying to develop a system that would succinctly whittle down the important events of the game for scoring purposes and for the ability to evaluate a particular player’s contribution to a team and individual games. In 1859, covering a match between the Brooklyn Excelsior and the Brooklyn Stars, Chadwick recorded the runs, hits, putouts, singles, and errors being the first instance of what we now know of as the box score."
The Baseball Box Score was First Developed by Henry Chadwick

"... In the early 1880s, Chadwick began his new position as editor of Spalding's Official Base Ball Guide. The official guide of the National League, it was distributed by his friend Albert Spalding, a sporting-goods magnate and a former pitching great for Boston and Chicago. Chadwick was among Spalding's mentors, though Spalding had a special talent for marketing and a good baseball mind of his own, as the success of his sporting-goods business demonstrated. Spalding and Chadwick remained friends despite the growing differences between them. As the business of baseball grew, so did Spalding's business, and Chadwick began to lose touch with that side of baseball's development. They found themselves divided as well on the issue of baseball's origins. Motivated by nationalism and the calculation that it was good for his business, Spalding propagated the idea, now discredited, that baseball's origin was entirely American, that it was invented in the United States and without any foreign influence. Chadwick maintained that baseball derived from the English bat-and-ball game he knew as rounders, which shared many of the same rules with baseball. Chadwick assumed, with good reason, that the English variant was parent to American baseball. Chadwick had said as much in the first Beadle guide, in 1860."
SABR

April 25, 1983 - To Get A Good Grasp Of The Game, Keep A Scorecard At The Ball Park
"... The father of the baseball scorecard, Henry Chadwick, was also the father of the K. Writing in the 1860s for a seminal baseball publication called Beadle's Dime Base-ball Player, Chadwick laid out the game's first scoring system. He numbered the players on the field (a bit differently from the way it's done today) and assigned letters to "record the movements of each player...A—put out on first base, B—put out on second base...F—put out by fly-catches...LD—put out by bound catches [of a foul ball. At that time, any batted ball caught on one bounce was a putout], RO—put out between the bases, HR—home run, and K—put out by three strikes." He went on to say, "The above, at first sight, would appear to be a complicated alphabet to remember, but when the key is applied it will be at once seen that a boy could easily impress it on his memory in a few minutes. The explanation is simply this—we use the first three letters of the alphabet to indicate the three bases, the first letter of the words 'Home' [and 'Run'] and 'Fly,' and the last letter of the words 'Bound,' 'Foul' and 'Struck.' " So, K for strikeout. A contemporary of Chadwick's, a reporter for The New York Herald named M.J. Kelly, is said to have personalized a system so detailed that he not only could pinpoint errors but could also distinguish at a glance between a 'slight muff,' a 'bad muff,' a 'total miss' and a 'total miss that was mitigated by a good attempt.' Kelly went so far as to consider how hard a ball was hit and even how many bounces it took before being fielded. As for balls that bounced too many times to be counted, Kelly even had a name for them—'daisy cutters.'"
SI Vault

amazon: Haney's Base Ball Book of Reference