A deeply researched biography of the new (smiley) face of tennis. A global star who has achieved more than Novak Djokovic, Rafael Nadal and Roger Federer did by this stage of their careers. At just 19 years old, Carlos Alcaraz won the US Open and became the youngest ever men's world number one. At only 21, he already had four Grand Slam titles.

For Alcaraz, everything - from his charm to his star power to his tennis mojo - starts with a smile. But there is a more complex character behind the smile. One who grew up in modest circumstances in a small village in Murcia in southern Spain. A man with strong family traditions who has a tattoo of his grandfather's favourite saying - 'cabeza, corazon y cojones' (brain, heart and balls) - inked on his left wrist.

Mark Hodgkinson talks to those who know Alcaraz best - including his coaches, old teachers and competitors - to provide a fascinating insight into a showman with ambitions of becoming the GOAT, the greatest of all time.