On-base percentage

An official Major League Baseball (MLB) statistic since 1984, it is sometimes referred to as on-base average (OBA),[a] as it is rarely presented as a true percentage.

The statistic was invented in the late 1940s by Brooklyn Dodgers statistician Allan Roth with then-Dodgers general manager Branch Rickey.

[3][4] In 1954, Rickey, who was then the general manager of the Pittsburgh Pirates, was featured in a Life Magazine graphic in which the formula for on-base percentage was shown as the first component of an all-encompassing "offense" equation.

Its perceived importance jumped after the influential 2003 book Moneyball highlighted Oakland Athletics general manager Billy Beane's focus on the statistic.

[7] Many baseball observers, particularly those influenced by the field of sabermetrics, now consider on-base percentage superior to the statistic traditionally used to measure offensive skill, batting average,[8][9] which accounts for hits but ignores other ways a batter can reach base.