Baseball Hacks

Measure Batting with Batting Average

Use R to calculate the most familiar statistic in baseball: batting average.

Batting average (AVG) is, by far, the most popular baseball statistic. It’s printed on baseball cards, flashed on scoreboards, and recounted by announcers during games. For more than 50 years, the best minds in baseball have talked about the problems with batting average, from Branch Rickey and Allan Roth’s work with the Brooklyn Dodgers in the 1950s, through Bill James and Pete Palmer’s work in the 1980s, to Michael Lewis’s book, Moneyball (W. W. Norton & Company).

I agree that batting average isn’t the best formula for measuring batting ability today, but I think it was once much more revealing. Batting average is one of the oldest statistics, dating back to the first time player statistics were published in the 19th century. In the early days of baseball, the pitcher’s role was not the same as it is today. The pitcher wasn’t supposed to trick batters with balls that looked like strikes, strikes that looked like balls, fastballs that flew past the batter, and changeups that slowly crossed the plate after the batter swung through the pitch. The early rules actually stated that a pitcher had to keep his arm stiff at the elbow and pitch underhand. The pitcher’s role was to throw the ball over the plate, allowing the batter the chance to put the ball in play. So, naturally, batting average excludes walks and the number of times a player is hit by a pitch because these ...