Dak Prescott came out of nowhere -- no slight to the residents of Starkville, fans of Mississippi State or fourth-round picks everywhere -- to sculpt one of the most outrageous seasons by a rookie quarterback in NFL history.Now that Cowboys fans have had eight months to revel in his performance and fully appreciate his accomplishments, only one question lingers:What does he do for an encore?The Cowboys have gone eight years without putting together back-to-back winning seasons.