Atopy is a predisposition toward developing certain allergic hypersensitivity reactions. Atopy may have a hereditary component, although contact with the allergen or irritant must occur before the hypersensitivity reaction can develop.
As of 2012, 63.9 percent of players playing in Major League Baseball are white. There is no way of telling the exact number due to the number of players.
Breaking Barriers: The First African American Players for each MLB Team (18) When he made his Brooklyn Dodgers debut on April 15, 1947, Jackie Robinson became the first African American to break the Major League Baseball color barrier. He won the Rookie of the Year Award that season, and went on to become the first black MVP in 1949.