LONDON, June 30 (Reuters) - John Tomic's passion for tennis and his family knows no bounds, occasionally landing him in hot water, but his methods have produced arguably the game's next big thing and he says there is more to come.
His 18-year-old son Bernard made a big splash at a rainy Wimbledon by reaching the quarter-finals but the coach and father reckons his daughter Sara could "dominate" tennis even more.
"His sister is 13 and she will be better than him. She's a better talent," the burly Croatian, who moved his family to Australia from Germany in the 1990s, told Reuters.
"She's number one in Australia for her age. She's in the under-14 squad. I have people working with her and she's in very good hands."
Sara must be good if she rivals Bernard, who became the youngest Wimbledon quarter-finalist since Boris Becker in 1986 and gave world number two Novak Djokovic a tough test before succumbing in four sets.
"In the next one and a half to two years when Bernard is more physically complete, I think he will dominate. There will be more variety of shots which will be very hard for his opponents to read," his dad said.
Tennis players' parents have long caused controversy.
Jelena Dokic's father, well-known on tour for his erratic behaviour, once threatened to kidnap his daughter while Andre Agassi described his dad as "violent by nature" in his autobiography.
Tomic's father has clashed with former Wimbledon champion Lleyton Hewitt's camp and once pulled his son off court in the middle of a match because of poor umpiring.
Fellow Australian Pat Cash, the 1987 Wimbledon champion, told Reuters of his concern over John Tomic's approach.
"Bernard's dad has been a great support, which is important, but I don't think in the long run it's healthy," he said.
"His father's been very driven, very pushy, and has rubbed a lot of people up the wrong way."
John just laughs off any criticism.
"People can say what they want. 100 people, 100 different opinions. I know what I am doing and I will continue to improve Bernard as a player," he declared.
"We have to do something different than the rest of the world. If we are the same, where will we be?"
Different, passionate, driven, call it what you want, John Tomic has clearly instilled a hunger to succeed in his children.
"He's coached me ever since I was a young kid and I started playing. Sooner or later he'll back off a little bit," Bernard told reporters.
"As soon as I have done well and made myself the best player I can, then I think my dad can slip out. It could be one year away or four years away. I don't know."
Tomic senior is not done yet despite his son's thrilling run to the last eight, which will improve his ranking from 158 to around 72 and make him the new Australian number one in the process.
"Family is the best thing for kids. That's my rule. You'll find many parents who have given their kids to coaches, but where are they now?," John said.
"Who else can you trust than your family?" he added, making real eye contact for the first time as a smile broke out on his face.
In Tomic's box against Djokovic was 2001 Wimbledon winner Goran Ivanisevic of Croatia and as the youngster was put through his paces in training there was no English being spoken.
So do the Tomic family feel more Croatian than Australian?
"In the blood we are Croatian but we are feeling 100 percent Australian. What's in the blood is something else, we are so proud to be Australian. A very nice nation is behind us. We are lucky," said Tomic senior.
If Bernard Tomic continues his Wimbledon form elsewhere, he will have more than just one nation behind him. (Editing by Mark Meadows)