The crowd at the Crucible exploded with delight. "Snooker's greatest showman, Ronnie O'Sullivan is in seventh heaven!" exclaimed the BBC commentator. "He beats Judd Trump 18 frames to 13 to equal Steven Hendry's modern-day record of seven world titles!"

At 47, the man nicknamed "The Rocket" had also become the oldest world champion - and some would say the greatest player - ever.

O'Sullivan had an extraordinary start to his career. He made his first century break at 10 and his first maximum break at 15. Aged 16, he turned professional. At 17, he won the British championship - the youngest player ever to do so.

But that same year, everything went wrong: his father was sent to prison for murder. Three years later, his mother was jailed for tax evasion.

O'Sullivan started drinking too much, became addicted to drugs, and was suspended for head-butting an official. At 25, he won his first World Championship but he felt so low during the tournament that he rang the Samaritans and became addicted to Prozac. 

By 34, he felt washed up. For two years, he did not win a single major competition. He says, "I was looking for the exit door and fighting the demons."

Then his manager persuaded him to visit Steve Peters, a professor of psychiatry at Sheffield University. "He was really in a bad place," Peters remembers. "It was quite disturbing to see."

Peters explained his theory that the brain has two sides. There are rational "human" parts and more primitive, powerful "chimp" parts. The chimp carries out essential functions, but is prone to panic.

To deal with this, Peters got O'Sullivan to write down his negative chimp thoughts and neutralise them with proven facts about his ability and achievements.

It took time to work - but the following year he was world champion once again.

Yes: You can be the most talented player in the world, but if you do not have the right mindset you can make a mess of everything. O'Sullivan would not be champion now if it had not been for Peters' help.

No: Mental strength is important, but physical ability is what really counts. It is O'Sullivan's natural gift that makes him so formidable. Even on an off day, he could beat most other players.

Or... Every sports star needs a combination of both. Many athletic clubs, and schools, have the Latin phrase "mens sana in corpore sano" ("A healthy mind in a healthy body") as their motto.