As Wimbledon gets under way, the BBC's Olly Foster tries to find the answer to the most popular question in tennis at the moment - why is Serbian talent so strong?
Ana Ivanovic is a dream for the women's game
I shall start with Ana Ivanovic. The 20-year-old Serbian is a dream for the women's game.
She must be one of the most beautiful women to have picked up a racquet, and graces both the front pages of magazines and the back pages of newspapers.
In the last month she has won the French Open - her first Grand Slam - and has become the world Number One. She starts Wimbledon as the top women's seed.
"It's the first time for me to be top seed at a Grand Slam," she says.
"And I'm very excited about it and obviously it comes with more pressure."
'Times were tough'
I caught up with the Wimbledon favourite, mingling with some celebrity sorts and very influential people, at a pre-tournament party in Kensington.
Ana stole the show. As everyone hung on her every word, I tentatively asked the question: "Why is Serbian tennis so good?"
"I don't think anyone does [have the answer]… It's hard to explain," she says.
"Thinking about it, we didn't have perfect facilities, we didn't have too many good coaches, the tennis federation wasn't so supportive, the times were tough and there weren't so many sponsors."
It is not just Ivanovic, who has made it through such difficult circumstances to the top.
There is Jelena Jankovic, the world Number Two, who won the Wimbledon mixed doubles title last year with Britain's Jamie Murray, and also Novak Djokovic, the third best player in the men's game and the Australian Open champion.
He has a theory.
"There was no system that brought us into professional[ism]. It's just a hunger for success, a mentality that we've been through a lot of difficult times in the past. We appreciate some things much more in life and we fight for every match," he believes.
All three were born in Belgrade at about the same time.
Djokovic is 21, Jankovic 23, and some of their earliest memories would have been of Monica Seles winning Grand Slams.
She was from Serbia when it was part of Yugoslavia, a local hero and inspiration for those wanting to follow her into the game - though tennis was hardly a priority in 1990s Serbia.
The era saw unrest, followed by conflict, Nato intervention and bombs being dropped on Belgrade. Serbia was at the heart of one of the most brutal periods in European history.
But the rights and wrongs of the war have nothing to do with the young trio with a talent for tennis.
What is more relevant is a swimming pool in Belgrade. It used to be heated in the early 1990s, but city authorities could not afford to keep it going.
It was drained, the floor levelled and four tennis courts squeezed inside the old tiled walls.
It looks just the same now as when the five-year-old Ivanovic turned up.
Even her first coach, Nicola Cetnik, is still there. He saw the potential straight away, as he did with Jankovic when she was there - but Ana was always a bit special.
"Ana was like the other children but she was well motivated,'' Cetnik told me, perched next to the deep end.
"But she had a passion. She wanted to play but she also wanted to learn. She had a dream and her dream became my dream too."
Everyone wants to be Ana these days, and the phone just has not stopped ringing at the swimming pool, where some shots are off limits because the tramlines are so close to the walls of the pool.
The courts are open from noon to midnight - but demand is so high that Cetnik worries about missing the next Ana.
"There are 100% more children these days, but we don't have the people or facilities to look after all of them," he complains.
Managing the huge increase in interest is the job of Dusan Orlandic, general manager of the Serbian Tennis Federation.
One wall of his office - in an unassuming house in Belgrade - is obscured by about 150 boxes of tennis shoes.
His annual budget has just been doubled to about £1m. The UK's Lawn Tennis Association (LTA) has a turnover 40 times that.
The comparison with the LTA is staggering. It must surely be an embarrassment to some at the £30m National Tennis Centre in South London.
The watchword there is "patience", as they try to instil a new tennis culture. They say that they have good juniors coming through.
Mr Orlandic makes that promise too, but without the same pressure. He has posters of Ivanovic, Jankovic and Djokovic on his wall. The LTA has Andy Murray.
"It's strange," Mr Orlandic tells me in an overgrown garden outside his office.
"When you have so much money and a National Tennis Centre like the one at Roehampton, it's not normal to have no good players!
Britain can only dream of a rivalry like that between Jankovic and Ivanovic
"You must find some talented players and then the players have everything! Maybe it's a problem that the boys and girls don't have motivation."
Murray has criticised the work ethic of some of his fellow British players. He is the only British man in the top 200. Serbia has six.
The British Women have more than Serbia but only one in the top 100 and Jankovic and Ivanovic are numbers one and two. So very small crumbs of comfort for Britain there.
Mr Orlandic thinks it may be in the blood.
"Our nation is a very talented nation for sport, not just tennis. We have very good basketball players, and footballers. We have good motor skills.
"And our players have much more desire than players from big countries. If you are living in England, France, Australia… everything is easier than living in Serbia."
Murray would not give the time of the day to anyone who suggested that Djokovic, a good friend, wanted to win more than he did.
Maybe Serbia has just got lucky, discovering a trio of world-beaters in the same generation.