Batters Faced measures the aggregate amount of batters that make a plate appearance during a pitcher's turn at play. Batters faced only includes successful plate appearances by the batter, such as hits, walks, outs or errors.
More about Total Batters Faced Leaders
Those who lead the league in total batters faced is the same way of saying those who lead the league in plate appearances against. League leaders are also likely to lead the league in total innings pitched, though the two are slightly different in that the most efficient pitchers in the game in terms of not allowing baserunners may lead the league in innings pitched but face slightly fewer batters. Pitchers will be credited with a batter faced due to any batting outcome; the only instance in which a pitcher will face a batter and not be credited with a batter faced is if a player begins an at bat and in the middle of the at bat a baserunner is thrown out on the basepaths for the third out of the inning.