2500 B.C.: The abacus is invented in ancient Sumeria
825 A.D.: Persian mathematician Muhammad ibn Musa al-Khwarizmi popularizes the decimal point
1859: Brooklyn sportswriter and early baseball promoter Henry Chadwick develops the box score
1917: The Al Munro Elias Bureau, forerunner of the Elias Sports Bureau, appointed official statistician of the National League
1947: Dodgers G.M. Branch Rickey hires Allan Roth, the first full-time team statistician; among other innovations, Rickey and Roth develop the formula for on-base percentage
1963: "Say you were standing with one foot in the oven and one foot in an ice bucket. According to the percentage people, you should be perfectly comfortable."
—Braves manager Bobby Bragan
1964: Johns Hopkins engineering professor Earnshaw Cook publishes Percentage Baseball, one of the first sabermetric treatises. It has a few hits (debunking the sacrifice bunt) and some glaring errors (dismissing the effects of player-handedness)
1977: While working as a night watchman, Bill James writes his first book, 1977
Baseball Abstract: Featuring 18 Categories of Statistical Information That You Just Can't Find Anywhere Else
1982: "Team speed, for crissakes, you get f------ fleas on the f------ bases ... getting thrown out. You get them big c---------- who can hit the f------ ball out the ballpark and you can't make any goddam mistakes."