ADELAIDE, Australia—A lot gets lost in translation when it comes to Australian Rules football.

The roles of a team’s 18 players are largely indecipherable to an onlooker from about any other country. Created by cricketers in the 1850s to keep fit off season, it is played on a grass oval up to 200 yards long with an ovoid ball that bounces unpredictably as players try to get it to goal posts. Each year, rules are amended or added.

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