Sage Kotsenburg Won Slopestyle With a “1620 Japan Air Mute Grab.” What Does That Mean?

American snowboarder Sage Kotsenburg won the first gold medal of the Sochi Games on Saturday morning after impressing the men’s slopestyle judges with a trick he calls the “Holy Crail.” (Yahoo’s Jeff Passan has the story of how a 17-year-old girl came up the name.) The maneuver, in which he……