Which country, host of the Argentine Open at Palermo, is regarded as the leading polo nation of the world?

A polo team puts four mounted players on the field, numbered one to four, where number one is the attacking forward and number four, called the back, is the main defender.

A polo match is divided into chukkas, also spelt chukker, of seven minutes each, and a match has four to six of them depending on the tournament; ponies are usually changed between chukkas because the galloping is so hard on the horse.

Sagol Kangjei, played in Manipur on the small Manipuri pony, is the game from which the modern rules of polo were drawn after British officers and tea planters saw it in the eighteen fifties, which is why Manipur is called the birthplace of modern polo.

The Ezra Cup is the oldest polo tournament in India and is played under the Indian Polo Association, along with other well known trophies such as the Sir Pratap Singh Cup and the Maharaja Jiwajirao Scindia Gold Cup.

Polo featured in five editions of the Olympic Games between 1900 and 1936 and was dropped after the Berlin Games of 1936, mainly because of the cost and difficulty of transporting strings of horses; Argentina won that last Olympic title.