This outrageous sports “documentary” brings together Andy Samberg and Kit Harington for a look back at a pair of fictional players from the not-too-distant past, who played on the longest and greatest tennis match of all time: a seven-day, five-set marathon that took literally everything out of them. In addition to highlights (and lowlights) from the match, the speciallooks back at the lives and careers of the competitors: Aaron Williams (Samberg), a hyper-malcontent, and Charles Poole (Harington), a dim-witted prodigy who carried England’s hopes for a tennis champion on his shoulders.