Serena & Venus Williams at the Olympics

Williams sisters Venus and Serena compete for gold at the All-England Club in London during the Olympics.

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 Czech Republic's Karolina Pliskova celebrates winning her group stage match with USA's Venus Williams REUTERS/Edgar Su

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 USA's Venus Williams in action during her group stage match with Czech Republic's Karolina Pliskova REUTERS/Edgar Su

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 Czech Republic's Karolina Pliskova in action during her group stage match with USA's Venus Williams REUTERS/Edgar Su

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 USA's Venus Williams reacts after losing her group stage match with Czech Republic's Karolina Pliskova REUTERS/Edgar Su

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 Czech Republic's Karolina Pliskova celebrates winning her group stage match with USA's Venus Williams REUTERS/Edgar Su

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 Czech Republic's Karolina Pliskova shakes hands with USA's Venus Williams after winning their group stage match REUTERS/Edgar Su

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 Czech Republic's Karolina Pliskova celebrates winning her group stage match with USA's Venus Williams REUTERS/Edgar Su

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 USA's Venus Williams reacts after losing her group stage match with Czech Republic's Karolina Pliskova REUTERS/Edgar Su

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 USA's Venus Williams in action during her group stage match with Czech Republic's Karolina Pliskova REUTERS/Edgar Su

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 USA's Venus Williams in action during her group stage match with Czech Republic's Karolina Pliskova REUTERS/Jeremy Lee

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 USA's Venus Williams in action during her group stage match with Czech Republic's Karolina Pliskova REUTERS/Edgar Su

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 Czech Republic's Karolina Pliskova in action during her group stage match with USA's Venus Williams REUTERS/Jeremy Lee

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 Czech Republic's Karolina Pliskova in action during her group stage match with USA's Venus Williams REUTERS/Edgar Su

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 Czech Republic's Karolina Pliskova shakes hands with USA's Venus Williams after winning their group stage match REUTERS/Edgar Su

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 Czech Republic's Karolina Pliskova reacts during her group stage match with USA's Venus Williams REUTERS/Edgar Su

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 USA's Venus Williams during her group stage match with Czech Republic's Karolina Pliskova REUTERS/Edgar Su

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 Czech Republic's Karolina Pliskova celebrates winning her group stage match with USA's Venus Williams REUTERS/Edgar Su

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 USA's Venus Williams in action during her group stage match with Czech Republic's Karolina Pliskova REUTERS/Jeremy Lee

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 USA's Venus Williams in action during her group stage match with Czech Republic's Karolina Pliskova REUTERS/Jeremy Lee

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 Czech Republic's Karolina Pliskova celebrates winning her group stage match with USA's Venus Williams REUTERS/Edgar Su

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 Czech Republic's Karolina Pliskova in action during her group stage match with USA's Venus Williams REUTERS/Jeremy Lee

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 Czech Republic's Karolina Pliskova celebrates winning her group stage match with USA's Venus Williams REUTERS/Edgar Su

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 Czech Republic's Karolina Pliskova in action during her group stage match with USA's Venus Williams REUTERS/Jeremy Lee

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 USA's Venus Williams in action during her group stage match with Czech Republic's Karolina Pliskova REUTERS/Jeremy Lee

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 Czech Republic's Karolina Pliskova in action during her group stage match with USA's Venus Williams REUTERS/Jeremy Lee

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 USA's Venus Williams in action during her group stage match with Czech Republic's Karolina Pliskova REUTERS/Jeremy Lee

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 USA's Venus Williams in action during her group stage match with Czech Republic's Karolina Pliskova REUTERS/Jeremy Lee

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 USA's Venus Williams in action during her group stage match with Czech Republic's Karolina Pliskova REUTERS/Jeremy Lee

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 USA's Venus Williams in action during her group stage match with Czech Republic's Karolina Pliskova REUTERS/Jeremy Lee

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 Czech Republic's Karolina Pliskova celebrates winning her group stage match with USA's Venus Williams REUTERS/Edgar Su

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 USA's Venus Williams reacts after losing her group stage match with Czech Republic's Karolina Pliskova REUTERS/Edgar Su

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 USA's Venus Williams reacts after losing her group stage match with Czech Republic's Karolina Pliskova REUTERS/Edgar Su

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 USA's Venus Williams reacts after losing her group stage match with Czech Republic's Karolina Pliskova REUTERS/Edgar Su

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 USA's Venus Williams reacts after losing her group stage match with Czech Republic's Karolina Pliskova REUTERS/Edgar Su

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 Czech Republic's Karolina Pliskova shakes hands with USA's Venus Williams after winning their group stage match REUTERS/Edgar Su

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 Czech Republic's Karolina Pliskova celebrates winning her group stage match with USA's Venus Williams REUTERS/Edgar Su

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 Czech Republic's Karolina Pliskova celebrates winning her group stage match with USA's Venus Williams REUTERS/Edgar Su

WTA Tour Finals

Tennis - WTA Tour Finals - Singapore Indoor Stadium, Singapore - October 22, 2017 USA's Venus Williams in action during her group stage match with Czech Republic's Karolina Pliskova REUTERS/Edgar Su