Former tennis players Steffi Graf and Andre Agassi take part in the Fundacion Telmex Mexico Siglo XXI (Telmex Foundation Mexico XXI Century) event in Mexico City, Mexico September 1, 2023. REUTERS/Henry Romero 

Former tennis players Steffi Graf and Andre Agassi take part in the Fundacion Telmex Mexico Siglo XXI (Telmex Foundation Mexico XXI Century) event in Mexico City, Mexico September 1, 2023. REUTERS/Henry Romero 

Former tennis player Steffi Graf takes part in the Fundacion Telmex Mexico Siglo XXI (Telmex Foundation Mexico XXI Century) event in Mexico City, Mexico September 1, 2023. REUTERS/Henry Romero 

Former tennis player Steffi Graf takes part in the Fundacion Telmex Mexico Siglo XXI (Telmex Foundation Mexico XXI Century) event in Mexico City, Mexico September 1, 2023. REUTERS/Henry Romero 

Former tennis players Andre Agassi and Steffi Graf take part in the Fundacion Telmex Mexico Siglo XXI (Telmex Foundation Mexico XXI Century) event in Mexico City, Mexico September 1, 2023. REUTERS/Henry Romero 

Former tennis players Steffi Graf and Andre Agassi take part in the Fundacion Telmex Mexico Siglo XXI (Telmex Foundation Mexico XXI Century) event in Mexico City, Mexico September 1, 2023. REUTERS/Henry Romero 

Former tennis players Steffi Graf and Andre Agassi take part in the Fundacion Telmex Mexico Siglo XXI (Telmex Foundation Mexico XXI Century) event in Mexico City, Mexico September 1, 2023. REUTERS/Henry Romero 

Former tennis players Steffi Graf and Andre Agassi take part in the Fundacion Telmex Mexico Siglo XXI (Telmex Foundation Mexico XXI Century) event in Mexico City, Mexico September 1, 2023. REUTERS/Henry Romero 

Former tennis players Steffi Graf and Andre Agassi take part in the Fundacion Telmex Mexico Siglo XXI (Telmex Foundation Mexico XXI Century) event in Mexico City, Mexico September 1, 2023. REUTERS/Henry Romero 

Former tennis players Andre Agassi and Steffi Graf take part in the Fundacion Telmex Mexico Siglo XXI (Telmex Foundation Mexico XXI Century) event in Mexico City, Mexico September 1, 2023. REUTERS/Henry Romero 

Former tennis players Steffi Graf and Andre Agassi take part in the Fundacion Telmex Mexico Siglo XXI (Telmex Foundation Mexico XXI Century) event in Mexico City, Mexico September 1, 2023. REUTERS/Henry Romero 

Former tennis players Andre Agassi and Steffi Graf take part in the Fundacion Telmex Mexico Siglo XXI (Telmex Foundation Mexico XXI Century) event in Mexico City, Mexico September 1, 2023. REUTERS/Henry Romero 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 15, 2020 Austria's Dominic Thiem celebrates winning his final match against Italy's Matteo Berrettini REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 15, 2020 Austria's Dominic Thiem celebrates winning his final match against Italy's Matteo Berrettini REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 15, 2020 Austria's Dominic Thiem celebrates winning his final match against Italy's Matteo Berrettini REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 15, 2020 Austria's Dominic Thiem reacts during his final match against Italy's Matteo Berrettini REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 15, 2020 Austria's Dominic Thiem reacts during his final match against Italy's Matteo Berrettini REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 15, 2020 Italy's Matteo Berrettini reacts during his final match against Austria's Dominic Thiem REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 15, 2020 Italy's Matteo Berrettini in action during his final match against Austria's Dominic Thiem REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 15, 2020 Austria's Dominic Thiem reacts during his final match against Italy's Matteo Berrettini REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 15, 2020 Austria's Dominic Thiem in action during his final match against Italy's Matteo Berrettini REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 15, 2020 Austria's Dominic Thiem reacts during his final match against Italy's Matteo Berrettini REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 15, 2020 Austria's Dominic Thiem in action during his final match against Italy's Matteo Berrettini REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 15, 2020 Italy's Matteo Berrettini in action during his final match against Austria's Dominic Thiem REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 15, 2020 Italy's Matteo Berrettini in action during his final match against Austria's Dominic Thiem REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 15, 2020 Austria's Dominic Thiem reacts during his final match against Italy's Matteo Berrettini REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 15, 2020 Austria's Dominic Thiem in action during his final match against Italy's Matteo Berrettini REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 15, 2020 Italy's Matteo Berrettini in action during his final match against Austria's Dominic Thiem REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 15, 2020 Austria's Dominic Thiem in action during his final match against Italy's Matteo Berrettini REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 15, 2020 Austria's Dominic Thiem in action during his final match against Italy's Matteo Berrettini REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 15, 2020 Italy's Matteo Berrettini in action during his final match against Austria's Dominic Thiem REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 15, 2020 Italy's Matteo Berrettini in action during his final match against Austria's Dominic Thiem REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 15, 2020 Austria's Dominic Thiem in action during his final match against Italy's Matteo Berrettini REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 15, 2020 Former German Minister for Foreign Affairs, Sigmar Gabriel watches the final match between Austria's Dominic Thiem and Italy's Matteo Berrettini REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 15, 2020 Austria's Dominic Thiem before his final match against Italy's Matteo Berrettini REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 15, 2020 Italy's Matteo Berrettini before his final match against Austria's Dominic Thiem REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 14, 2020 Netherlands' Kiki Bertens in action during her semi final match against Czech Republic's Petra Kvitova REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 14, 2020 Czech Republic's Petra Kvitova in action during her semi final match against Netherland's Kiki Bertens REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 14, 2020 Netherlands' Kiki Bertens in action during her semi final match against Czech Republic's Petra Kvitova REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 14, 2020 Netherlands' Kiki Bertens in action during her semi final match against Czech Republic's Petra Kvitova REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 14, 2020 Czech Republic's Petra Kvitova in action during her semi final match against Netherland's Kiki Bertens REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 14, 2020 Czech Republic's Petra Kvitova in action during her semi final match against Netherland's Kiki Bertens REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 14, 2020 Austria's Dominic Thiem and Italy's Jannik Sinner touch rackets after their semi final match REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 14, 2020 Austria's Dominic Thiem in action during his semi final match against Italy's Jannik Sinner REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 14, 2020 Italy's Jannik Sinner in action during his semi final match against Austria's Dominic Thiem REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 14, 2020 Austria's Dominic Thiem in action during his semi final match against Italy's Jannik Sinner REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 14, 2020 Italy's Jannik Sinner in action during his semi final match against Austria's Dominic Thiem REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 14, 2020 Austria's Dominic Thiem in action during his semi final match against Italy's Jannik Sinner REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 14, 2020 A spectator sits in the stands during the semi final match between Austria's Dominic Thiem and Italy's Jannik Sinner REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 14, 2020 Austria's Dominic Thiem in action during his semi final match against Italy's Jannik Sinner REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 14, 2020 Austria's Dominic Thiem in action during his semi final match against Italy's Jannik Sinner REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 14, 2020 Austria's Dominic Thiem in action during his semi final match against Italy's Jannik Sinner REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 14, 2020 Austria's Dominic Thiem in action during his semi final match against Italy's Jannik Sinner REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 14, 2020 Italy's Jannik Sinner in action during his semi final match against Austria's Dominic Thiem REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 14, 2020 Austria's Dominic Thiem in action during his semi final match against Italy's Jannik Sinner REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 14, 2020 Austria's Dominic Thiem before his semi final match against Italy's Jannik Sinner REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 14, 2020 Latvia's Anastasija Sevastova in action during her semi final match against Ukraine's Elina Svitolina REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 14, 2020 Latvia's Anastasija Sevastova in action during her semi final match against Ukraine's Elina Svitolina REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 14, 2020 Ukraine's Elina Svitolina in action during her semi final match against Latvia's Anastasija Sevastova REUTERS/Hannibal Hanschke 

Tennis - bett1ACES exhibition tournament - Steffi Graf Stadium, Berlin, Germany - July 14, 2020 Ukraine's Elina Svitolina in action during her semi final match against Latvia's Anastasija Sevastova REUTERS/Hannibal Hanschke