The Mendoza Line is an expression in baseball deriving from the name of shortstop Mario Mendoza, whose poor batting average is taken to define the threshold of incompetent hitting. The cutoff point is most often said to be .200[1] (Mendoza's career average was slightly better than that, at .215)[2] and, when a position player's batting average falls below that level, the player is said to be "below the Mendoza Line".

I was not familiar with the term, but useful concept. Reminds me of something I read recently about the “Goat”, the West Point cadet finishing at the bottom of his class.