We hear from Sascha Zverev's fitness coach, Jez Green and best friend, Marcelo Melo after the 21-year-old's victory at the Nitto ATP Finals. All that plus Borna Coric joins us for a chat, Mats Wilander looks at the history of the tournament and ATP Executive Chairman and President of the ATP, Chris Kermode explains why the ATP is making changes on and off the court.