It's a matter of personal preference. Some such as Alex Rodriguez of the New York Yankees and I believe Jason Vartiek of the Boston Red Sox choose to wear high socks over their pants and others prefer to have their pants come over their socks.
Some players are very superstitious and change their look when they are in a slump and when they start hitting they keep that look. Others just always wear their clothes the same way. Its the same as when players use different batting gloves with different colors and designs as well as cleats and Baseball mitts. Its just a matter of preference.
Why does "who" were their pants legs at the knees? If you mean some minor leaguers, in some cases the major league team dictates how its players must wear their pants on their minor league affiliates. All major leaguers don't wear their pants legs to the ankles. Some wear them only to their knees. There is no set rules for major leagues on where their pants legs must go. Most wear them where they feel most comfortable. Some players who wear their pants legs hige are Soriano of the Cubs, Berkman of the Astros, Varatek of the Red Sox. Some players change from game to game high sometimes, low at other times.
its no longer cool
they start wearing shorts and pants
Button-Up Jersey, Baseball Pants, Long Socks, Cleats, Baseball Cap, Etc.
they wear jersey's, hats,socks,belts,cleats,pants,and sometimes necklaces.
Modern baseball uniform pants are either unhemmed or "open" straight leg bottoms while some still prefer to wear the elasticized hemmed bottoms that gather around the chin or ankle. The straight leg open pants do not need to secure to anything during the game, they are worn just as you would straight leg pants and do not have to be anchored down in any way.
Wore what?...pants, underwear, glasses, false teeth. Be more specific with your question.
A uniform: Cleats, Socks, Jersey, pants, sliding shorts, belt, hat or helmet, and a cup (optional)
Pants. Im a hockey player.
Southland Baseball Pants
Mankini's
cups Baseball socks baseball pants hat jersey and cleats