And yet for many, it's hard to shake the feeling her best years might already be behind her. After holding the No. 1 ranking for 85 consecutive weeks and 104 overall as a teen, Ko failed to win a single tournament in the entirety of 2017. Ko is considerably younger than the current Rookie of the Year, Park-Sung hyun, and has already achieved more than most golfers do in a lifetime, but some commentators — not least her former coach David Leadbetter — are asking "What's wrong with Lydia?" and wondering if the Kiwi will ever hit the same heights again.
"It's already my fifth year on the tour and I feel like I kind of set the bar very high for me at an early age," Ko tells CNN Sport. "That's why expectations went sky high." A look beyond the list of broken records reveals Ko is human just like the rest of us. Even the most dominant athletes can suffer from dips in form and confidence. "I would never think of myself as a phenom," she says. "I'm not comparable to Messi and Ronaldo ... I think there are so many greats and legends that have done so much more than me."
It certainly wasn't sheer physicality that set her apart from every other golfer who has played the game to date during her formative years on tour. "It was more of a mental thing," says Ko. "When I was out there playing my best, I was out there not worrying about where the balls were going to go, or if I was going to hole certain putts. Going into tournaments I felt, 'Hey, I can possibly win this.' That's why, even now, confidence is such a big thing for me, building belief."
Over the course of a 25-minute conversation, Ko returns to the word "confidence" 11 times. She compares it to "a 15th club in the bag," arguing it's "almost the most important." As Ko puts it, "Week in week out, the amount of talent or skill doesn't change that much, but confidence can be a huge momentum builder." Imagine her relief at this April's Mediheal Championship
, then, when the "best" three-wood she's ever hit set Ko up for a first LPGA Tour victory in almost two years.
It was there, on the shore of California's Lake Merced, that Ko had won her first tournament as a pro, lifting the 2014 LPGA Swinging Skirts trophy while celebrating her 17th birthday. Returning to the scene a few days after her 21st birthday, the circumstances could hardly have been more different. Where four years ago there seemed to be no limits to her potential, this time victory ended a wait of 43 starts without a win. Where before she was the golden girl of golf, this time her ranking had slid to No. 18 and the decisive putt was greeted by tears of relief.
"I've never been that emotional before," she told CNN Sport the following day. "When that putt dropped I was like, 'Oh my God.' A lot of emotions, my whole team and my family have worked really hard for this moment."
Her family have been described as suffocating influences, with Leadbetter telling ESPN
that Ko's parents "feel like they know her best, know her moods" and Golf Digest
that "they tell her when to go to bed, what to eat, what to wear, when to practice and what to practice."
Ko, though, knows Gil-hong and Bong-sook better than anyone. "My family around me and my team are the people that are always going to keep me grounded no matter what and not go up and down like a rollercoaster," she says, having emigrated with them from Seoul to New Zealand as a child.
"That is so important I think in golf. So I've been very fortunate to have people keep me more level-headed. Even if things aren't going well, trying to keep me confident. If things are going really well, getting me to not go too high at that moment."
After all, many teenagers would have had their heads turned by the sort of global acclaim Ko received. In 2014, on her 17th birthday, the New Zealander was one of just five sportspeople to be named in Time Magazine's list of the 100 most influential people in the world. The only other athletes were FIFA World Player of the Year Cristiano Ronaldo, Super Bowl champion Richard Sherman, gay NBA icon Jason Collins and tennis legend Serena Williams. It wasn't unwarranted. Between her victory in the season-ending 2014 CME Group Tour Championship and the 2015 ANA Inspiration, Ko shot 29 consecutive rounds under par, equaling the record mark set by the great Annika Sorenstam in 2004.
"She was amazing around the green, hit shots pretty much where she wanted every single time," her first coach Guy Wilson told CNN. In late 2015, several hall of famers were asked for their take on Ko. "The world is her oyster," said Amy Alcott. "She is extremely mature and ready for her age," said Sorenstam. "Lydia is the joyful phenom," said Carol Mann. Even now, she remains the youngest woman in history to win a major title, courtesy of her victory at the 2015 Evian Championship aged 18 years, four months and 20 days. "I tried to take everything as a routine," Ko recalls of her time as the game's undisputed No. 1. "With the expectation and pressure, all you can do when you're out on the golf course is try to make as many eagles, birdies or pars as possible."
But of course nobody's completely immune to the pressures of being the player to beat — particularly when the slightest mistake is scrutinized. "I think the big thing was, where you're the No.1 ranked player and you're not really in contention, people go: 'Oh no, what's wrong with her?!'" Ko explains. "Just because you're No. 1 doesn't mean you're going to win every week! That was kind of the mindset."
She cannot be accused of complacency or resting on her laurels. Ko's changed coaches, caddies and her equipment in a few years more often than most players do in a whole career. Perhaps most drastically, she also altered her swing, forsaking her natural, somewhat idiosyncratic approach in favor of Leadbetter's so-called "A-Swing" — a move criticized in certain golfing circles.
Leadbetter worked with six-time major winner Nick Faldo
in the mid 1980s when the Englishman was world No. 1 — as well as with Greg Norman and Ernie Els. But the swing coach was part of further wholesale changes Ko made to her backroom team in late 2016, just months after helping her secure five consecutive top-three finishes at majors, including two victories.
Writing earlier this year in a piece
entitled "The Grass isn't always Greener," Leadbetter said: "The toughest thing from our standpoint is to see the deterioration in her game compared to her first three years as a professional. We might not have all of the answers, but she certainly was on track to become one of the greatest LPGA players of all time.
"She obviously still has the talent but it's not always an easy task to climb back up the mountain top." Ko's not thinking about her comeback in such grandiose terms. "All I can do right now is play my best at this very moment," she says, "not think about what happened in the past or what might happen in the future."
'Enjoy the moment'
Not worrying could be the key to Ko recovering her best form. Looking back at when she won the 2012 CN Canadian Open at the age of 15, the player recalls she "laughed the whole time and didn't really know what was going on." There was a freedom to her game -- unfettered by the weight of expectation that comes with being placed on a pedestal as a phenomenon.
Today, she says the best piece of advice she's ever been given was from Stacy Lewis, a former world No. 1 who also went several years without an LGPA Tour win. "She called around the end of last year and said, 'Hey, you're playing well. Don't worry about what happened in the past. All you can do is just focus and enjoy the moment now,'" Ko recalls. "And that was really huge for me, because she's been in my shoes before." Ko has come to terms with the fact that not everyone peaks at the same time.
"I guess every athlete is so different," she muses. "Some athletes, they've won the same amount of titles as another, but one might have won the majority at the end of the career, or maybe progressively like Dustin Johnson's done, having won every season for a really long time."
Golf grand slam?
Ko tells CNN she plans to retire when she's 30 years old -- acknowledging "it's pretty amazing that Tiger Woods and Phil Mickelson are having such amazing careers at such an old age" -- and says "if I've gotta get things done, I've gotta get things done before then!"
But she strongly refutes any suggestion that her early success means she has less to play for going forward. Her biggest goals are to complete the career grand slam and once again compete at the Olympics, having won silver at Rio 2016. Aged 21, with at least nine years ahead of her, Ko still has plenty of time.