Water polo
Water polo is a relatively new sport that, in spite of its name, has absolutely nothing to do with Polo, which uses horses and it is not based on Polo in any way, shape or form.
Water Polo is, fundamentally, a water-based version of handball, in which attempts are made to throw the ball into the net. No other part of the body may be used to touch the ball. As with handball, it is played at a ferocious speed, with injuries common. It requires players to be expert swimmers and to also have very strong arms. Because of the physical stress put on the body while playing Water Polo, most games have very short quarters of only a few minutes each, in the Olympics they are 8 minutes per quarter but at junior levels as short as 5 minutes.
The rules are fundamentally the same as in soccer as it is essentially based on soccer rather than handball directly, as are a large proportion of team-based sports. As with hockey, new rules are added to adapt to the fact that it is in the water with swimming and hands used.
The official history states that Water Polo was inspired originally by Rugby and in early versions of the sport the rules more closely resembled Rugby than Soccer, but as time went on the rules were changed to look more like Soccer, as it made more sense in the water. Its original name was in fact Water Rugby but pronunciation issues about how to describe different British dialects with "ball" led to it being mispronounced as "polo" instead of "ball", leading to the name change, which has stuck. Since the rules grew to resemble soccer more than rugby, calling it Water Rugby was no longer appropriate anyway.
The game was created as an experiment in England and Scotland in the late 19th century by William Wilson, who intended to see Rugby played in rivers and streams for some reason.
Water polo has never been particularly popular as a worldwide sport in any country, yet for some reason was introduced to the Olympics in 1900 and has remained an Olympic sport ever since, in spite of never being popular anywhere in the world.
A lot of university students the world over experiment with Water Polo as an exercise in learning a very physically difficult sport.
It is described as one of the most physically difficult sports in the world to play.
Olympic Gold winners include: Great Britain, United States, France, Germany, Hungary, Italy, Yugoslavia, Soviet Union and Spain, with Hungary, Italy, Yugoslavia and Great Britain winning on multiple occasions and Hungary the reigning champions for the past 3 Olympics. The only year that United States won, in 1904, they won 1st, 2nd and 3rd and were the only country who presented teams, with different states in USA sending their own teams to compete against each other.