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How do young sports stars become successful at the top?

27 August 2014 Last updated at 16:54 BST

Tennis player, CiCi Bellis has become the youngest player to feature in a Grand Slam main draw for over nine years.

At just 15 years 152 days old, she beat 12th seed Dominika Cibulkova at the US Open.

So what exactly does it take for a young sportsperson to make it to the top?

Martin went to find out more.