The Stirrup
“Aside from a few players like Barry Zito, Jonathan Sanchez, Juan Pierre and Jamie Moyer, the sight of stirrups in the major leagues is rare. (Greg Maddux wears socks with stirrups sewn on, which only half counts.) The most popular look today seems to be having your pants pulled down around the tops of the shoes, which is actually how the early baseball players of the 1840’s and 50’s wore their pants. According to the Baseball Hall of Fame, it was not until the 1868 Cincinnati Red Stockings decided to don knickers and expose their colored socks that this style changed. Strange to think of Manny Ramirez’s long baggy pants being a throwback, but that actually seems to be the case.”

Rollie Fingers, via Fuck Yeah High Socks
“The stirrup actually came about to provide players a measure of safety as well as comfort in the days before colorfast dyes. In those days a player who got spiked by an opponent could get blood poisoning if the dye were to run into the cut. As a result players wore white socks under their colored stockings, which are still today called “sanitary socks.”
Then the problem of fitting this double wrapped foot into a pair of spikes came up and thus the stirrup was born. With its double arched opening, it allowed the foot to fit into the spike while also allowing the player to wear two pairs of socks. Originally players did not expose much of their white under socks, but as the century progressed stirrups were stretched tighter and tighter until in the 1980’s players were actually cutting their stirrups and adding fabric to make for a longer and thinner look.”

Source: Twin City Knitting
“What’s happening now, especially since the 1980s is that the uniforms are not worn uniformly,” said Tom Shieber, the senior curator at the Baseball Hall of Fame. “It used to be that the differences were fairly subtle with minor exceptions, but now everybody is interested in differentiating themselves from everyone else.” – The New York Times
More over at the Baseball Hall of Fame.
