Even baseball fans who aren’t into statistics are familiar with batting average. If it starts with a 4, that’s historically good. Starting with a 3 is good, a 2 is OK, and if it starts with a 1 … well, even a casual fan knows it’s time to send that player to the minors.

But this season, as baseball’s collective batting average has sunk to .243, the dreaded “1” is showing up more and more. Batters, emboldened by teams that prioritize power over consistency, increasingly swing for the fences, and with that their averages have plummeted. Many have even sunk below .200, a threshold known as the Mendoza Line, which was named for Mario Mendoza, a light-hitting infielder in the 1970s.

Through Thursday’s games, 20 players with at least 200 plate appearances — enough to be considered something of a regular — were hitting below .200. By season’s end they could be joined by several more who are near those thresholds in batting average or plate appearances.

In the last full season, 2019, there were only 15 such players. Further back, it was difficult to keep a roster spot with such a low average. Twenty years ago, in 2001, there were only five sub-.200 hitters, and 50 years ago, in 1971, there were six.

The Best of the Bunch

A player hitting below .200 can keeping his job for a variety of reasons. Perhaps the manager expects the player to improve. Maybe it’s a youngster who needs at-bats. Or maybe the options behind him are even worse.

But some of those Mendoza Line hitters are providing actual value to their teams. That’s because, of course, batting average doesn’t tell the whole story.

Take Paul DeJong of the St. Louis Cardinals, who is hitting .196 in 370 plate appearances. He plays pretty good shortstop, a key defensive position, and has 17 home runs. Baseball Reference credits him with 1.3 WAR, the best total among our sub-.200 hitters.

Ryan Jeffers of the Minnesota Twins also pulls his weight. Despite batting .199, he has 13 homers in 277 plate appearances and plays the valued position of catcher. His on-base plus slugging percentage of .673 is not All-Star caliber by any means, but it tops the sub-.200 group.

Eugenio Suarez of the Reds is batting .183, but has been sent to the plate 535 times, the most of any player in the group. He has kept himself in the lineup by hitting 27 home runs, which account for 31.4 percent of his 86 hits.

And the Worst

Unfortunately, some hitters who are batting under .200 don’t have much else to show for their seasons. They just can’t hit. At the bottom of the table is Michael Perez of the Pirates, who is hitting .141, the lowest single-season mark this century for a player with 200 or more plate appearances. Perez must be an awfully good catcher to put up with that ineffectiveness as a batter.

Outfielder Jackie Bradley Jr. of the Brewers is hitting .163, without much power and with few walks. That gives him an O.P.S. of just .501. That would be even worse if he hadn’t shown a knack for getting hit by pitches — 10 times this season. He is excellent defensively and can play all the outfield positions, however, which is why he has kept getting at-bats.

By WAR, the weakest of the players are Suarez and Jarred Kelenic, a 21-year-old outfielder for the Mariners. Among the game’s top prospects heading into this season, Kelenic has 13 home runs, but his .602 O.P.S. isn’t great and his defensive numbers are quite poor.

On Mendoza’s Edge, but Thriving

While none of the sub-.200 players are grade-A assets this season, a few players who are flirting with the Mendoza Line are actually quite valuable.

Joey Gallo, who was traded from the Rangers to the Yankees this year, is hitting .204, but would be welcomed to just about any team in baseball. Though he leads the majors in strikeouts, he also leads the American League in walks, with 109. Add in 38 home runs and Gallo has an .837 O.P.S. to complement his top-shelf defense, which has added up to 4.8 WAR. Sure the Yanks would love it if Gallo could hit .300 — or even .250 — but his package of skills makes him a real asset despite the batting average.

Ha-Seong Kim of the Padres is hitting .206, but plays such solid middle infield that his WAR is a respectable 2.0.

Our Pioneer

And what of Mario Mendoza, the player whose name has for decades been linked with mediocrity. Was he unfairly maligned by a myopic focus on batting average? Did he have hidden skills that helped his team?

Well, not at the plate. Mendoza played for parts of nine seasons with the Pirates, Mariners and Rangers from 1974-82. While his career average was .215 he had five seasons in which his average fell below the dreaded line that bears his name.

He brought little else to the plate offensively: His best season of on-base percentage was .286, and his slugging percentage was only over .300 once. He played semi-regularly in only two seasons, 1979 and 1980, with a bad Mariners team; his best walk total in those years was 16, and his best homer total was two.

But he did play shortstop, a difficult position to fill, and enjoyed a good defensive reputation, including the nickname the Man With the Silk Hands. And after his major league career was over he returned to Mexico where he had a long tenure as a player-manager in the Mexican Leagues.

In 2000, he was inducted into the Mexican League Hall of Fame. His lifetime average there was .239.