Water Polo (WPO)
Water polo has been part of the Summer Olympics program since the second games, in 1900. A women's water polo tournament was introduced for the 2000 Summer Olympics. Hungary has been the most successful country in men's tournament, while the United States is the only team to win multiple times at the women's tournament since its introduction. Italy was the first to win both the men's and women's water polo tournaments. [Wikipedia]