Rafael Nadal was 15 years old when he turned professional as a tennis player. About 18-and-a-half years after that, he matched the men’s singles record for winning the most number of Grand Slam titles in the sport’s history.

Nadal’s extraordinary talent was unmissable right from the days he was winning under-12 titles in Spain. By the time he turned pro, many had predicted he was going to achieve great things. After all, he was only 14 when he defeated fellow Majorcan and top-10 player Carlos Moya in an exhibition match and just 18 when he beat then-world No 2 Andy Roddick in the Davis Cup finals.

While Nadal’s staggering achievements – his Grand Slam titles and otherworldly record on clay – are well documented, it is worth looking back at his formative years and all that he went through. He was coached by his father’s younger brother, Toni, from the start and made a number of sacrifices as he climbed through the ranks and went on to become one of the greatest athletes ever.

Here’s a look at seven stories from Nadal’s childhood that offer some insight into what went made him the champion player he is today:

How Toni spotted his talent

Rafa was just three years old when his uncle Toni spotted the rare talent he possessed. Toni was himself a top amateur player in Spain at one time and coached hundreds of kids at the Manacor Tennis Club.

Toni gifted Rafa a tennis racquet and took him along to his academy for a hit. And it didn’t take long for him to identify what set his young nephew apart.

“When I hit the ball to Rafael, he went towards it. He didn’t wait for the ball to arrive to him,” Toni was quoted as saying by BBC Sport. “Normally, when I sent a ball to a small kid, he stood and waited until the ball arrived at him. But my nephew, he went looking for it. For me, this was special.”

Struggles, sacrifices and Toni’s tough love

Toni had plenty of children at his academy but he made sure he gave special attention to Rafa. But the youngster had to endure a whole lot too. Toni demanded discipline and sacrifices which often rattled the youngster.

In his 2011 autobiography – Rafa: My Story – he wrote about how he wasn’t allowed to celebrate titles as a kid and had to keep his focus on the next training session planned for him. He admitted being afraid of Toni and dreaded having solo practice sessions with him.

Under Toni’s tutelage, Rafa had to: sweep the red dirt after practice, collect all the balls sprayed across the court, and have balls hurled at him if his attention swayed.

Rafa even admitted he felt “insecure” at times and spoke with his mother about what he was being put through. His father had expressed concern too. But the family decided it was best for Rafa to continue training with his uncle.

“I believe in the work and I believe in the players who are strong enough to cope with the intensity of this work,” Toni told BBC Sport. “I cannot understand another style of life. In my opinion, you always have to know your place in the world. This is why I was like this with Rafael. I knew he could cope.”

Rafa would go on to win 16 of his 20 Grand Slam titles with Toni as coach.

Refusal to leave home

By the time Rafa was 14, he had made a name for himself in the Spanish junior circuit by winning multiple age group titles. Those achievements earned him a tennis scholarship in Barcelona but he decided to stay put in Manacor.

His parents – Sebastian and Ana Maria – and uncle Toni reckoned it was best for Rafa to continue his training at home. His results were getting better each year and even though a move to Barcelona may have worked, the family believed Toni was the right man for the job as Rafa prepared to turn professional.

“I did not want to leave home and I’m glad [I didn’t] looking back,” he wrote in his book. “[Even though] Toni was grating on my nerves, I knew I had a good thing going with him. Because Toni was right. So often infuriating but, in the long run, right.”

Choosing tennis over football

Miguel Angle Nadal, Rafa’s other paternal uncle, was a professional footballer who represented the senior Spanish team and even played club football for RCD Mallorca and FC Barcelona.

Rafa was introduced to football by Miguel Angel at a young age and took a liking to the sport immediately. He played a lot of football in his school days and even took part in competitions.

But by the time he turned eight, Toni had intensified his tennis training sessions and Rafa had to make a choice. He decided to drop football and focus on building his career as a professional tennis player. However, he made it a point to take out some time each week for football with his friends.

Two-handed forehand

Another major decision Rafa took was when he was 10 years old. It was to stick with a left-handed forehand. For up until then, he used both hands to play that stroke.

Not many are aware of this fact but Rafa uses his right hand for all his everyday tasks. Be it writing, eating, throwing or any other task, Rafa’s dominant hand in the right one. However, it was uncle Toni who identified that he had a stronger left hand while playing tennis.

“At the start, he played with two hands but used one hand to direct,” Toni told Tennis Magazine. “I had the impression that he was stronger on his left side than on his right side. So, I figured that he was left-handed; it’s as simple as that.”

Winning with a broken finger

When Rafa was 11, he participated in the Spanish Under-14 National Championship and lost in the semi-finals. The next year, he returned determined to win the title. But in the very first round itself, he had a nasty fall on the court and ended up breaking the little finger on his left hand.

However, what happened from there on was the first real indication of Rafa’s extraordinary grit. Using just four fingers to grip the racquet, he refused to throw in the towel and went on to win the tournament. It was Toni’s relentlessness that had rubbed off on the young champion.

“I often let him train with bad balls in bad places. I extended the 90-minute trainings over and over again – without comment. So that he learns to persevere. We have often made a game on twenty points. Most of the time I let Rafael lead to the matchball in order to win,” Toni was quoted as saying by Blick.

“He was the best student you can imagine. Rafael was always very willing to learn. But hardness and rigour should never be a method, but only a means. Over time, my high demands became his own. That’s the optimal case. Because a player should do things because I convince him. Not because I demand it.”

Fear of the dark

Rafa is known for his fiercely competitive nature on the court. His never-say-die attitude is the stuff of legend and he never looks fazed by his opponents no matter the match situation.

However, off the court, Rafa has always been a mild-mannered person. He, in fact, has had a fear of the dark since he was a young boy. His on-court ‘Raging Bull’ persona on one side, Rafa has always preferred sleeping with at least one light or television screen switched on.

The tennis legend is even scared of thunderstorms and hides under cushions each time there is one. “He is not comfortable with thunder and lightning,” Nadal’s mother was quoted as saying by The Cut, while his sister termed him “a bit of a scaredy cat.”