From a 1982 Sports Illustrated article on different ways hardcore baseball fans have to keep score at the game, here’s a bit about how Bill James did it, in anticipation of later systems keeping detailed track of the flight and bounce of the batted ball:
Bill James, the statistics fanatic who annually cranks out his analytical Baseball Abstracts, uses so many intricate notations that his score sheets are about as easy to read as a bowl of alphabet soup. James admits that some of what he does “has gotten cumbersome” but says he continues using his complex system because “detailed scoring sharpens your focus on the game, so that you start seeing things that you weren’t seeing before.” How detailed? “One thing I almost always do is to score hits according to where they land on the field,” James says. “An s4 is a single hit up the middle, between the second baseman and the shortstop. [His system assigns a 1 to an infield hit, a 2 to a hit between the first baseman and the line, a 3 to a hit between the first and second baseman, and so on around the field, to 16.] A 2b 16 is a double hit between the rightfielder and the rightfield line.”
On a James scorecard an infield hit, as you might imagine, is rarely left as an unadorned s1. James squeezes in s1.1b to record a bunt single fielded by the pitcher. He writes s1.5c for a chopper fielded by the third baseman. And he pencils in s1.4t to note a tap gathered up too late by the second baseman. He has, of course, a system for recording the game pitch by pitch to indicate if the pitcher is getting ahead of or falling behind the hitters and to show which batters consistently swing at the first offering. A typical notation of defensive positioning is BAD44(GL)—13G. Taking a deep breath, James explains, “That means the infield is back, the outfield deep, the centerfielder a little around to right with a gap in left, and the first and third basemen are guarding the lines.” The 44 refers to degrees, as in one less than 45, which to James means straightaway center. It’s obvious that he pays strict attention to the game. “My head is never down when the ball is in play,” says James.
Perhaps more interestingly, SI added this note:
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.