If you're cynical about sport, fed up with excess, sick of cheats, weary of drugs, tired of ego, go meet Mo Martin. Just seek an audience. Because this American is 1.60m of weapons-grade optimism.

She ain't no big-money-raking, game-dominating, fairway- shrinking, camera-attracting, fashion icon. No, she's a world No. 57 whose career earnings at 33 are less than what Lydia Ko, 18, won last year, but she is as important to golf.

Because sport can't survive on the skills of a handful of great champions, it needs an array of athletes to sustain it. The dreamers, the doers, the desperate. Or just a kid called Mo from California who couldn't afford golf lessons, got onto the LPGA Tour finally at 29 and then won a Major as her first and only title. Cool is the word you're searching for.

But more than that, as sport is increasingly suffocated by minders, and hard-to-reach athletes speak like wound-up toys, we need evangelists like Martin, who signs balls for volunteers, who leans against a wall after a humid round and chats for 20 minutes and whose affection for the game sings from every sentence.

"I love," she says of golf, "how you constantly have to improve. I love how difficult it is. I love the beauty of it because I have never been to an ugly course. I love how it brings different people together." She was just a soapbox short of a sermon on why kids should play this game.

So if you ask, why does Mo Martin - a mid-level player, possibly unrecognisable to you - matter, it is because she returns a little bit of innocence to sport.

Mo Martin matters also because she's a short hitter surviving just fine in a planet that's manic about length. Even Donald Trump, politics' latest Pinocchio, is now swearing he hits it 285 yards. Everyone's trying to turn a meticulous sport into a macho one and Martin's heard people talking about driving a ball 50 yards longer. To which she asks, "Do you know how hard it is to hit it 10 yards further?"

Martin was No. 142 on tour in driving distance last year but wait, hold that sneer. Because she averaged 232 yards and if you're now thinking, damn, that's more than me, it's about to get worse because she weighs only 52kg - probably while holding a golf bag.

And so, first lesson: She gets more out of her body than us. Second: She was No. 1 on tour in accuracy and thus straighter than us. Third: She says "I know exactly how far I hit the ball" with every club which of course is never the case with us.

Mo Martin matters because life has pushed her around but it never knocked the perspective out of her. She didn't have "a lot of money growing up," but her father had a book by golf great Ben Hogan, he built a cage in their driveway and off she went.

Quietly she tells stories; intently, we should listen. She remembers going to Jack In The Box, a fast-food place, when she was seven with her mother, brother and friend, ordering one spicy, crispy chicken sandwich which was cut into four pieces.

You're thinking, poor thing; she thought: "I am so lucky, I got a quarter. It's the best thing in the world."

It's a perspective she's evidently retained as an adult. When she won the Ricoh Women's British Open in 2014, a commentator asked if this was the "biggest dream that's ever come true for you", to which she breezily replied: "I think I am living the dream every day, really no matter what happens." In a time when too many athletes sound like we should be grateful to watch them playing sport, she actually sounds grateful to be playing sport.

Mo Martin matters because she's persistent or has been since she was a six-year-old kid hanging around a Los Angeles par-three course till 10pm. For six years she played the lower-level Symetra Tour, driving her Chrysler PT Cruiser to events, staying with local families, being supported by friends, inspired by her grandfather, and taking one of the grand risks of a young life.

Or as she explains it, "You're betting on your (sporting) self". You're convinced your talent will stretch and you believe your time will come. And so when people - this writer included - idly describe victories, like Martin's Open, as a miracle, we're wrong. Because they aren't engineered in heaven, they're just built with sweat under the sun.

It is this persistence which Martin's father recognised and he nicknamed her Mighty Mo after the battleship USS Missouri. On the deck of that particular ship, in another time gone by, Japan surrendered. On the peaceful, cultivated golfing lawns of today, Mo Martin endeavours as an athlete never to quit.

And that, of course, always has to matter.