The sport of baseball has come a long way since its creation more than one hundred fifty years ago in the United States. After staying within the confines of America for most of its life, the sport sprang forth from its homeland after World War II and is now the most popular sport in such countries as Japan, South Korea, Venezuela, and the Dominican Republic. It is also among the more popular sports in Mexico, many of the non-British Caribbean countries, and Australia, and is gaining in popularity throughout Europe.

Fans of baseball are attracted to the unique combination of skills, athleticism, and strategy that it requires of its players, as well as its reliance on statistics. Perhaps more than any other sport, baseball is a game of stats. Batting average, ERA, OPS, and WHIP are just some of the metrics used to determine a player’s value.

But what about the “Mendoza Line”?

If you’ve watched any amount of baseball in the last forty years, you’ve probably heard the Mendoza Line used as a stat; but the thing is, it’s not an actual stat!

The term Mendoza Line actually began as a joke and as a reference to Mexican professional baseball player Mario Mendoza’s lack of batting prowess. Mendoza was a shortstop who originally played in the Mexican professional leagues before becoming what is known as a “journeyman” in Major League Baseball, playing for the Pittsburgh Pirates, Seattle Mariners, and Texas Rangers in the 1970s and early 1980s, before returning to Mexico to finish his playing career.

Mendoza was known as an excellent fielder, but he was never a very good Major League hitter, and he had a difficult time batting about a .200 average, which is not very good in baseball. The phrase first surfaced during the 1979 Major League season when some of Mendoza’s teammates told Kansas City Royals’ slugger and Hall of Famer George Brett that if he didn’t turn his season around, he’d be in danger of sinking “below the Mendoza Line.”

Baseball is a sport of practical jokers—Brett was never in any danger of batting below .200, but the joke caught on and was picked up by Chris Berman.

If you’re an American, you’re probably familiar with Chris Berman, the ESPN announcer and personality who brings a bit of humor to his analysis and broadcasts. In 1979, most people had not heard of Berman, in fact, most people had not heard of ESPN either—it was a new network that year and wasn’t available most places. But Berman began using the term “Mendoza Line” that year, not only to refer to Mario Mendoza’s lack of hitting luck in the Majors, but also to refer to the .200 average in general.

By the mid-1980s, sports announcers all over the United States were regularly referring .200 as the Mendoza Line and now, with baseball’s increasing international popularity, it can be heard uttered in Asia, Latin America, and even Europe.

Although the term began as a big joke on Mario Mendoza, he ended up having the last laugh. His career Major League Baseball average was .215.