Stirrups were uniform socks commonly worn by baseball players up until the mid-1990s, when Major League Baseball players began wearing their pants down to the ankles, setting a trend soon picked up by players in minor and amateur leagues. Until then, stirrup socks had been an integral part of the traditional baseball uniform, giving them a distinctive look. A high sock was needed because baseball players wore knickerbockers, worn by many boys in the late 19th century and into the 20th century. The stirrup socks served to display team colors, stripes or team logos. For example, for several years the Minnesota Twins wore navy-blue stirrups with "TC" on the side, for "Twin Cities", and in 1987 an "m" was placed on side. The Houston Astros wore navy blue stirrup socks with an orange star on the side. The stirrup sock colors were also the basis of team names, including the Cincinnati Red Stockings, Boston Red Sox, and Chicago White Sox. For these reasons, traditionalists lament the recent "sockless" look in baseball uniforms. Stirrup socks are worn on top of long socks called "sanitaries," usually white in color. This is because early color dyes in the outer stirrup sock were thought to pose health issues, as well as the fact that the inner, less expensive white sock could be changed more frequently. The stirrup sock lacked a foot, instead having a loop which fits within the arch of the foot. Over the years, the stirrup loop tended to get longer, exposing more of the white undersock, thus creating a look unique to baseball. However, by the 1980s many players were pulling the loop so high that only the white undersock and the loop itself showed – the rest of the game sock being hidden by their pants. Eventually, this reached a point where some players only wore vertical lines for stirrups. For many years teams had enforced rules so that uniforms were worn "uniformly", including team socks. For example, Leo Durocher, longtime manager of the Chicago Cubs, had a measuring stick in the clubhouse. Players were required to match the length of their stirrup loops to this stick at about 4 inches, exposing only a small part of the white sanitary. Increasingly lax regulation of uniform codes by MLB eventually contributed to players ignoring the traditional look. The Official Baseball Rules are silent on stirrups, but the fact that some players on a team wear them while others do not seems to be in violation of Rule 1.11 which states that "all players on a team shall wear uniforms identical in color, trim and style," as well as Rule 1.11 that states "no player whose uniform does not conform to that of his teammates shall be permitted to participate in a game." The freedom to wear high stirrups or not is remarkable considering how nowadays uniformity is otherwise enforced by MLB. For example, during a 2007 game against the Yankees, with the Yankees threatening to score, Red Sox manager Terry Francona was suddenly called away from the game and questioned by a league executive as to whether he was wearing the required uniform jersey beneath his blue pullover. He wasn’t pleased. Although some teams — particularly college teams — continue to wear traditional baseball stirrup socks, another option has been to replace the stirrup/undersock with a "2 in 1" combination sock that mimics the real thing, or simply to wear a single solid knee-high sock with knickers. The trend back to knickers and high socks is particularly evident among youth and high-school teams. A few pro players, such as Taijuan Walker of the Arizona Diamondbacks, Derek Holland of the Texas Rangers, Melvin Upton, Jr. of the San Diego Padres, Bryce Harper of the Philadelphia Phillies, Casey Janssen of the Washington Nationals, Daniel Descalso of the St. Louis Cardinals, Josh Outman of the Cleveland Indians and Steve Cishek & Juan Pierre of the Miami Marlins, Chris Archer of the Tampa Bay Rays, J.R. Graham of the Minnesota Twins, Chris Taylor of the Los Angeles Dodgers, and Francisco Lindor of the Cleveland Indians have been spotted wearing genuine stirrups recently to much fanfare. Several players on the Philadelphia Phillies will either wear stirrups over white sanitary socks, or over red socks, as the Phillies stirrups sport their Liberty Bell logo. The minor-league Springfield Cardinals wear a 2-in-1 version of the traditional St. Louis Cardinals' game sock that looks very much like the real thing. Other sports also use, or have used, stirrup socks, but traditionally wore a white sweat sock over, instead of under, the colored stirrup game sock. For many years American football officials commonly wore black baseball-style stirrups as part of their uniform although this was done away with by the early 2010s as black full-length slacks replaced the traditional white knickers. There are still some sock companies manufacturing stirrup socks for baseball and other sports, including Twin City Knitting Company in Conover, North Carolina.
