Bloomsbury Sport

One hand is for power and the other one for taking aim: ‘In my case, I am right-handed, so I use the right hand to give power to my stroke and the left hand to aim at the target and give direction to my stroke.’

Dominic Thiem, who was 20 when he broke into the world’s top 100,

The worst mistake you can make is to lift the ball up too high over the net, as that will give your opponent an easy passing shot: ‘You want to keep the ball as low as possible.’

Maria Sharapova, who won Wimbledon at 17, and who has won all four grand slam titles

Take responsibility for yourself – you have to be mature enough to realise that the most important thing is what you do, not what anybody else does: ‘I think it’s something that’s within. Of course, everyone is going to have difficult moments, but it’s really about how you get up from those moments. You can have the best people in the world helping you, but if you don’t tell yourself to grow up inside, and to be positive and strong, then you won’t ever become mentally tough.’

not to think too much about who is watching you

positive each day as the game challenges you.

you work well and work hard, you can do anythin

Nothing in this life is that difficult.’

Try not to care about what people say about you