The Mendoza Line is baseball jargon for a .200 batting average, the supposed threshold for offensive futility at the Major League level. It derives from light-hitting shortstop Mario Mendoza, who failed to reach .200 five times in his nine big league seasons. When a position player's batting average falls below .200, the player is said to be "below the Mendoza Line".

In baseball, batting average (BA) is determined by dividing a player's hits by their total at-bats. It is usually rounded to three decimal places and read without the decimal: A player with a batting average of .300 is "batting three-hundred". If necessary to break ties, batting averages could be taken beyond the .001 measurement. In this context, .001 is considered a "point", such that a .235 batter is 5 points higher than a .230 batter.