You can say what you like about Nikolay Davydenko, but the way he withstood the flak and innuendo that surrounded him after the betting controversy has been amazing.
Ever since the allegations surfaced after he pulled out of a tournament in 2007 the whispers and looks have followed him everywhere, but he has kept his focus and concentration superbly to stay in the top tier of tennis. It's been unreal.
But Davydenko is a very strange kettle of fish. There is a real hardness about his character that keeps him so consistent - yet at the same time that toughness seems to disappear against the top players in Grand Slams.
More than any other player he has a habit of going exactly as far as the seedings say he should, but no further. The rest of the year - including in Masters events, as he showed at the weekend - his resilience, motivation and skill are such that he can beat any player in the world.
He's a very fine ball striker, tactically excellent, moves extremely well and, when his confidence is there, is extraordinarily difficult to beat.
Except in Grand Slams, where he has never got beyond a semi-final, and has shown a weakness that flies in the face of everything else about him.
Having said that, the same mental weakness has come out once before. I'll never forget watching him at the 2007 Paris Masters, just a few months after the initial match-fixing allegations and a week after he received an official warning and £1,000 fine from the ATP for not trying hard enough at a tournament in St Petersburg.
There, in Paris, Davydenko completely lost the ability to serve in what was the worst case of the yips I've ever seen in tennis. He just couldn't get the ball into the box, and even when admonished by the umpire he still couldn't do it.
There was no question in my mind that he was giving his best effort and the only thing you can conclude is that his normally well-hidden mental frailties had reared their heads once more.
Davydenko was cleared of match fixing in 2008 after the longest investigation the game has seen.
But tennis needs to remain vigilant. I don't believe for one second that the sport would ever see a betting scandal at a major event, but there are plenty of minor tournaments out there where the prize money, prestige and rankings points on offer could be comfortably outweighed by a hefty bet and a thrown match.
It's great news that Alex Bogdanovic won a Challenger event this weekend - but we've always known that Bogo has the talent when he finds the confidence.
So why doesn't he produce the goods more often? For my money, the question is whether he works hard enough on his game - and the only person who can answer that is the man himself.
Compare him to a player like Jamie Baker, who has put together a fantastic run in ITF tournaments over the last few weeks. Jamie has been blessed with nothing like the raw talent that Bogo has, but has always worked his socks off to get the best from himself.
Can Bogdanovic look himself in the mirror and say the same thing?
From what I've heard at the LTA, the British number two has renewed his effort of late, really putting in the hours.
If so, and if he can start to overcome the demons which have always stopped him producing his best tennis under pressure, maybe he can finally start showing what he's capable of.