Last year a survey of ATP players asked who they would nominate to play a tiebreak for them, if their lives depended on it.
The answer, apparently, was almost universal, and it wasn't Roger Federer, Novak Djokovic or Rafa Nadal.
It was John Robert Isner, mostly because of his near unreturnable serve.
Isner stands at 2.08m, and the ball, when hit at the height of the toss, is struck from more than three metres, around the height of the top of the umpire's chair.
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If Isner doesn't ace you, then he forces you to hit a return at shoulder height, from well behind the baseline, of a serve travelling at 200km/h or more.
It's a recipe for success, because even when his opponents get a racket on the ball, Isner's large frame is bearing down on the net, ready for the volley.
The towering American provided more evidence of his prowess yesterday, defeating British world No 69 Kyle Edmund 7-6 (5) 7-6(5) in one hour 56 minutes.
Edmund fought hard – with nine break opportunities across the match – but Isner didn't give him a chance on any of them.
"I swatted away nine of them, in pretty comfortable fashion," said Isner, who sent down a staggering 25 aces. "That's a good sign going forward, I'm going to need to do that."
But how does it feel, possessing the serve that most, including icons such as Federer and Djokovic, regard as the best in the sport?
"It's cool, [but]I don't really think about it that much," said Isner. "I know some of the great players have said that I maybe have the best serve in the game, and that's very cool to think that someone like Roger Federer would say that about me."
"It's what I do. I'm obviously very big, because I am so big, I'm able to serve well. It's as simple as that."
Matches involving Isner aren't everyone's cup of tea and the rallies can be very short. It makes for a different kind of spectacle, albeit still with plenty of tension.
But Isner has remained a popular figure here.
Partly because he is a two-time champion, and also because he is a charismatic, endearing character, shown yesterday after a potentially nasty incident when one of his smashes hit a young spectator in the side of the head.
After a short lob from Edmund, Isner whacked the overhead which flew up off the court, and hit the boy, 11-year-old Aucklander Charlie Middleton, sitting in the second row of the Robinson stand.
Play was stopped momentarily, as the umpire asked if he was okay, while a concerned Isner looked on from the other side of the court.
A ballboy then delivered some ice, which the young fan held against his head for the next few minutes.
At the next change of ends Isner went to talk to the Middleton, before an extended conversation after he won the match.
"I know his name is Charlie," said Isner, who remarked that he showed the toughness of a 'future All Black'.
"I told him I couldn't give him a racket during the match because I kinda need 'em. But I intend to give him a racket before I leave town. It hit him in the side of the head, in the ear."
"[But] he was as tough as nails, didn't ever complain, he just shook it right off," added Isner. "I told him I'm sorry and thank you for hanging in there."
Edmund had his moments yesterday - it's rare to see so many break opportunities against the Isner serve - but couldn't take them.
In contrast the 34-year-old Isner found his best in the big moments, at one point serving three consecutive aces to get out of trouble. And he was imperious in the tie breaks, while Edmund almost looking resigned to defeat once each breaker rolled around.
"I think I played better than my last match," said Isner. "I thought I played a really good second set. I was playing more assertive and getting more balls back in play."
History is now on Isner's side, as every previous occasion he has reached the last four, he has gone on to lift the trophy.
"That is a good omen," said Isner. "I did not know that. Hopefully I can continue that trend."