The horses are slick with sweat, veins bulging, feet dancing through a maelstrom of legs and mallets and flying clods of earth, 6,000 pounds of flesh tumbling after a tiny white ball. The riders are all furious angles, jabbing their mallets blindly beneath their saddles. But Adolfo Cambiaso appears calm. He lifts a gloved hand and swings the head of his mallet in a perfect arc through the tangle of horse and human to thwack the ball and send it clear toward the goal. It’s the final game of the 2016 Argentine Open—the most important polo match of the year in the most polo-obsessed country in the world—and there