LONDON, UK - With Ashleigh Barty's ascent to World No.1, the Australian has quietly rewritten the rulebook to tennis success.

The 23-year-old's two-year hiatus from the sport is well-known by now, particularly her foray into cricket during it, and in Eastbourne this week Barty reiterated what she's said all along: "I don't think I'd be standing here still playing if I didn't take the break." With her characteristic knack for downplaying drama, Barty refuses to see her decision as a trailblazing one - more a natural necessity for her at that point in her life. But the fact is that leaving the game completely at the age of 18 and missing the years commonly held to be some of the formative in a professional player's development, and subsequently scaling the heights that Barty has, is unprecedented in the modern game.

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"She's not following anyone's path," agreed coach Craig Tyzzer, an integral part of her team for the past three years. "She's basically doing it the way she wants to do it." 

The softly-spoken Tyzzer speaks with deep respect for Barty as a person as well as a player, someone whose ability to take pressure in her stride is down to the fact that, secure in herself, success motivates her but does not validate her. "What you see is what you get with Ash, and that's the best thing about her," nods Tyzzer. The time off, he says, was crucial in getting her to this stage.

"We've talked about coping with expectations, and that's what Ash has done really well since coming back - whereas before she wasn't able to cope with it," he says. Tyzzer points out that, as used as tennis fans are to preternaturally poised teenagers able to reel off lists of sponsors with an ad-worthy smile in their trophy acceptance speeches, this isn't really normal.

"We expect all these players to have all these capabilities when they're thrust into an environment that's not natural," he says. "To be able to talk in front of people, to be able to talk to reporters, to be able to front to TV cameras - the expectations are huge and not everyone can handle that."

READ MORE: 'I'm still the same Ash Barty that I was three weeks ago' - Barty 

Changing mentality is easier said than done, of course, and to Tyzzer it's come down to Barty now fully knowing who she is. "It's all along the lines of feeling your value," he says. "There can be two voices - one can be saying, 'You're not good enough, you're not going to win,'; the other one can be, 'You need to tell yourself you are good enough and you can win.' Often it's which one you listen to, and Ash has done a really good job of telling herself she's worthy of doing it and she's capable of doing it."

Of course, the tennis itself is also crucial: Barty is a throwback player with a classic style that you can imagine succeeding 30 or 40 years ago. In an interview this week, none other than Billie Jean King rhapsodised about Barty's ability: "You know what's happening to tennis? It's going back to an all-round sport!" the WTA legend said. "You see the way she plays - it's like the old days. She's got a sliced backhand, she can hit it, she goes to the net, she can stay back. I think it's great."

Barty has also been successful in modernizing her game to be relevant in the athletic, power-dominated 2019 era, though. Tyzzer has worked on increasing the power on her forehand to complement the variety of her backhand, but it's the efficacy of the Roland Garros champion's serve despite standing at just 5'5½" that has been truly impressive: she is ranked No.4 on the ace leaderboard for 2019 so far, with the remaining players in the Top 5 - Kiki Bertens, Karolina Pliskova, Naomi Osaka and Petra Kvitova - all 5'11" or taller.

"She packs a lot of power for someone her size," says Tyzzer. "But we've worked specifically on the variations of direction, speed and spin, and that's been a big part of what she's done over the past two years."

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No sooner has any player graduated to the ranks of Slam champion or ascended to World No.1 that they face a new set of expectations: the pressure to justify their new status. Not everyone is able to meet those - but all of Barty's work means Tyzzer is confident in his charge. "I don't think it'll actually bother her," he asserts. "She's been so good at just shutting down and working on knowing that this is another tennis match, it's like every other tennis match. That's been the biggest change in her - not worrying about expectations and what other people think, just what we talk about and what we analyse.

"She did such a good job of it last week - after the French Open I wasn't sure how she'd handle it but then to get put under pressure again where she had to play a final where, if she won, she'd get to World No.1 - and she just took it in her stride."

Ashleigh Barty, coach Craig Tyzzer (second from right) and the rest of her team (Jimmie48/WTA)

Barty's talent and resilience hasn't gone unnoticed by the rest of the Tour. In Eastbourne last week, Kiki Bertens unhesitatingly named her as the title favorite for Wimbledon next week, and while King described the draw as "wide open", Barty was nonetheless the name she ultimately singled out. It's a sentiment also shared by Martina Navratilova in a column for and ATP World No.43 Nick Kyrgios, who described his fellow Australian as "probably the most talented tennis player I've seen in a long time".

"I always knew she was going to be a champion at some stage, just how badly she wanted it. I actually think she's probably one of the favorites for Wimbledon, for sure," he continued. "Australia had been waiting for that next player to win there, and I think she's our best chance. She's amazing, she's gonna pile them up."

Read more: Winning Wimbledon would be a 'Herculean effort' for Barty, says Evert

Meanwhile, Aryna Sabalenka's coach Dmitry Tursunov urged other players to consider Barty's story when thinking of their own career path. Every tennis player ought to expect "the going to get tough"; what matters, according to Tursunov, is how you deal with that adversity and whether you can keep working towards your ambitions.

"Talk to any of the top players and they'll say there were periods when they thought about quitting and not playing tennis again. Barty stopped playing for a bit as she had to reassess some things and mature and grow in order to fill her shoes. But then she came back to win the French Open," said the Russian. 

"If you want to be good at something - whether it's basket-weaving or tennis - it's going to be hard work. You're going to go through periods when you don't enjoy it. It's work. It's not a hobby. It's not a fun pastime. I'm sure there are lots of moments when you don't enjoy it. You have to find something you love about it as otherwise you're going to be miserable and you need to get the hell out of tennis. The going gets tough."

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Members of the next generation are now looking to Barty as a role model. Seventeen-year-old Catherine McNally, who possesses a similar slice-heavy game, described her as "an inspiration" both on and off court this week en route to qualifying for her first Wimbledon. "She just kind of keeps her head down and goes to work, and I like that about her," said the American teenager.

Tyzzer would concur. "Ash will now always be a Grand Slam champion, which is fabulous for her," he said. "But it doesn't mean that she's going to walk out there and beat everyone she plays now.  She knows that she has to put the work in, and nothing will change in that respect. She'll do her time."