Mario Mendoza

In his first season in Seattle, Mendoza made a career-high 401 plate appearances in a career high 148 games and 132 starts at shortstop. While providing the Mariners with a steady glove, he ended the season with a .198 batting average—making him only the fourth major leaguer ever to play as many as 148 games in a season and fail to break .200. The following year, however, Mendoza fared better at the plate, batting .245 in 277 at-bats.

Mendoza was inducted into the Mexican League Hall of Fame in 2000. After managing the San Francisco Giants' double A Texas League affiliate Shreveport SwampDragons in 2002, Mendoza returned to Mexico to manage Dos Laredos in 2003, the Angelopolis Tigres in 2004, the Olmecas de Tabasco in 2005 and 2006, and the Piratas de Campeche in 2007. He was named manager of the Broncos de Reynosa during the 2012 season. He was dismissed as Reynosa's manager in May 2013 after the team started in first place with a 30-23 win-loss record; team leadership cited differences of opinion with Mendoza.

Bill Bavasi, an executive with the Anaheim Angels, believed Mendoza was someone who had potential as a manager and offered him the reins to the Angels' Class A advanced California League affiliate, Lake Elsinore Storm, for the 1998 season. He remained with the Storm until they became a San Diego Padres affiliate in 2001, managing his son, Mario Jr., in 2000.

Mendoza received an invitation to spring training with the Pirates in 1983. After failing to make the team, he accepted a player-coach position with their triple A Pacific Coast League affiliate, the Hawaii Islanders. After one season in Hawaii, Mendoza returned to Mexico as a player/manager of the Monclova Acereros.

Following the season, Mendoza was sent to the Texas Rangers in a blockbuster deal along with Larry Cox, Rick Honeycutt, Willie Horton, and Leon Roberts for Brian Allard, Rick Auerbach, Ken Clay, Jerry Don Gleaton, Richie Zisk, and Steve Finch. In 1981, Mendoza split time at short with Mark Wagner with Mendoza receiving the bulk of the playing time, and finishing with a .231 batting average. However, the following season he was released in June 1982 with a .118 batting average.

The 'Mendoza Line' phrase was then overheard and used by George Brett. In an interview in 1980, during his pursuit of a .400 season batting average, Brett reportedly stated, "The first thing I look for in the Sunday papers is who is below the Mendoza line." The reference caught the attention of ESPN announcer Chris Berman, and the "Mendoza Line" became part of popular culture. Brett also praised the defensive abilities of Mendoza, claiming Mendoza robbed him of sure base hits on several occasions with exceptional defensive plays.

Mendoza claims that the term was invented in 1979 by his Mariner teammates Bruce Bochte and Tom Paciorek. Bochte and Paciorek would tease Mendoza about his low batting average, as he struggled to hit .200 for the season. Although Mendoza finished his career with a batting average of .215, the Mendoza Line is almost universally accepted as being at .200, as this was the average Mendoza flirted with all that year. (From May 10 to the end of the season, Mendoza's average fluctuated between .175 and .210, usually staying within just a few points of .200 before finishing below the Mendoza Line at .198.)

Mendoza remained with the Pirates as a defensive replacement through 1978, playing some second and third base as well. In five seasons with the Pirates, Mendoza batted .221, .180, .185, .198, and .218, respectively. Following the 1978 season, Mendoza's request for a trade was granted as he, Odell Jones, and Rafael Vasquez were sent to the Seattle Mariners for Rick Jones, Tom McMillan, and Enrique Romo on December 5, 1978.

On June 28, 1977, Mendoza pitched two innings of mop up duty in the second game of a doubleheader against the St. Louis Cardinals. The Pirates, having used seven pitchers in a doubleheader with the Montreal Expos two days earlier, had already used three pitchers in the first-game 6–1 loss. Completely depleted of pitchers, Pirates manager Chuck Tanner started relief pitcher Grant Jackson in the second game, pitching six innings despite giving up ten runs (only six of which were earned), and the Pirates were already down 10–3 by the time Mendoza was handed the ball. After getting Keith Hernandez to line into a double play to end his first inning of work, Mendoza gave up a three run home run to Ken Reitz the following inning, giving Mendoza a career 13.50 earned run average on the mound.

Mendoza played four seasons in the Pirates' farm system before debuting with the Pirates on April 26, 1974 as a pinch runner for Willie Stargell. With the Pirates down 3–2 in the ninth inning to the Houston Astros, Mendoza scored the tying run in the Pirates' 4–3 victory. For the season, Mendoza batted .221 in 91 games, but had only 177 plate appearances as he was primarily a defensive replacement when starting Pirates shortstop Frank Taveras (who himself only had a .246 batting average in 1974) had been pinch hit for late in a game. He reached the postseason for the only time in his career during his rookie season. He started game three of the 1974 National League Championship Series against the Los Angeles Dodgers, and went one for three with a walk and an RBI infield single.

Mendoza first caught the eye of the Pittsburgh Pirates while playing for the Mexico City Red Devils (Diablos Rojos) of the Mexican League in 1970. His ability for picking grounders prompted the Pirates to purchase Mendoza's contract from Mexico City.

Mario Mendoza Aizpuru (born December 26, 1950) is a Mexican former professional baseball infielder. Mendoza, a lifetime .215 hitter, is best known for being the source of the name for the threshold for batting ineptitude, the "Mendoza Line", meaning a batting average of .200. Mendoza managed in the minor leagues and in Mexico after his Major League Baseball (MLB) playing career. He is a member of the Mexican League Hall of Fame.