After a day of competition, swamp soccer players find a way to wash away all the grime, around 3 a.m. at a lake in Hyrynsalmi, Finland, in July of 2017. More than 2,000 people ventured to the remote backwaters of central Finland recently for the 20th annual Swamp Soccer World Championships, further proof of the country’s growing penchant for screwball sports competitions. (Janne Kšrkkš/The New York Times)