You could even mount an argument for Brendon McCullum - now prominent in the realms of our greatest batsmen ever - and the world-class force that is Kane Williamson. It will be fascinating to watch the Black Caps in the upcoming World Cup even if they may not yet be in the same mental-strength territory.
At the end of last year, I wrote that the most fascinating sports story of 2014 would likely be Ko - a babe in arms in world sporting terms who changed just about everything that had taken her to the doorway of achievement; her long-time coach, a new management group, her clubs, a tweaked swing and she hasn't even had a consistent caddie, using many different bag-carriers in her first year on the LPGA tour.
It looked too much for a rookie 17-year-old. But after three LPGA wins and more than US$3 million for the year, Ko is stronger than ever.
You could see it on that nerve-wracking four-hole playoff with Spain's Carlota Ciganda - a seemingly never-ending journey up and down the tough 18th hole at the CME Group Tour Championship.
Ciganda looked tight, Ko joked with her caddie, chatted with the other playoff competitor, Paraguay's Julieta Granada, laughed and swigged from her water bottle like a young girl on a social round of golf with nothing more to think about than whether her nails needed doing afterwards. The cameras, the crowd, the pressure, all caused her no more stress than tying a shoelace.
She missed a 15-footer the first time they got to the 18th. No matter. Ice-cool Ko allowed herself a puzzled frown and then she was right back in grinder's groove.
Ciganda should have won the match when she produced a brilliant approach shot for a six-foot putt. She cracked. The putt missed, Ko halved the hole and Ciganda's next approach shot found the rough. It was a display of mental toughness from a 17-year-old, persevering with percentage play on a hole unlikely to yield a birdie but easily lost by bogey.
Her detractors will say we shouldn't crow. After all, she hasn't won a major. It's a ludicrous thing to say in anyone's first year in LPGA golf. If ever there was a case of when, rather than if, Ko is it.
That same mental strength was on show from the Kiwis in the Four Nations. Only a moron would suggest the tide has forever turned but the nature of the double victories over the Kangaroos suggests the Kiwis have lost that cultural cringe. Forwards like Kevin Proctor, Martin Taupau, Greg Eastwood, Issac Luke and Jesse Bromwich monstered the Australians.
Bromwich and Co did much of the damage but skipper Simon Mannering was a superb marshall and link. He tackled everything that moved, ran well on attack and made correct decisions consistently - a calming, collected influence. An 80-minute footballer, he led from the frontal lobe, displaying the technique and coolness needed to beat a side who, even weakened, demonstrated just how hard they are to overcome.
Finally, the All Blacks and their consistent displays of mental toughness on tour. Those who screeched earlier this year about Richie McCaw's future, or lack of it, must be feeling daft now. I just watched McCaw against Wales. Somehow, that bloke is still aiming his body at ruck after ruck. He gets to a vast number and is highly effective when he gets there.
He still has an astonishing engine, a work rate almost matched by two other forwards - Kieran Read and Brodie Retallick. Add to that backs like Smith C, Smith B, Dan Carter and Cory Jane who also make the right decisions on attack and defence and you have the nucleus of a team whose physical and ball-playing prowess has led to efficiency and the mental strength to crack opponents in the last 20 minutes.
It's the best possible sign that back-to-back World Cups are not just possible but eminently achievable. And if that doesn't happen, we'll all need some mental strength ...
