Stefanos Tsitsipas beat Dominic Thiem 7-6 6-2 7-6 for the biggest title of his career at the 2019 Nitto ATP Finals in London's 02 Arena. I detail the third set tiebreak that decided the match, Thiem's bold shot-selection and Tsitsipas's steady play. In comment response, I discuss why the Big-3 are less dominant in non-majors and if Federer is still a threat in Australia. Plus, how discouraged should Medvedev be and what he needs to improve next season.