"Mental strength" says top coach Nick Bollettieri on what made Serena and Venus Williams dominant

Serena Wiliams and Venus Williams both had times when they dominated WTA tennis and top tennis coach Nick Bollettieri explained why it was that say.

Serena Williams and Venus Williams are some of the best tennis players that ever played the game and it's not by chance. Both of them possess tremendous talent and worked very hard from a very young age to become so dominant but there is more to that story. It's hard to see any siblings topping the famous Williams sisters and top coach Nick Bollettieri explained why:

"Maria Sharapova, who arrived at my academy in Florida aged 8, was distinct from very young. Aged 11 or 12 she was running her own show, on court, desperate to get to work every day. The Williams sisters were the same. They had physical abilities beyond compare, but it was focus, not letting outside distractions overtake you."

According to Bollettieri that is why they were so dominant for so long especially Serena who is widely regarded as the greatest tennis player of all time. The coach finished up with:

“That kept them so dominant for so long."