Caroline Wozniacki's Grand Slam problem is not mental, she simply does not have the right game for it, whereas the attacking Petra Kvitova can dominate for years to come.
It's good that we have a player who's actually playing a lot of tournaments managing to win a Grand Slam. I don't think it would have been great if Serena Williams or one of the others had won because they are part-time players now. Kim Clijsters is a part-time player, and Venus Williams is a part-time player too: they choose their tournaments.
With Serena, it's unfortunate in terms of what happened to her with the blood clot - but she largely picks her battles anyway. It would have been a kick in the teeth to the Tour if she'd come back and won it after a year out. Still, I was amazed to see her go out the way she did.
Given that I thought Li Na or Maria Sharapova might have taken it - playing regularly now, in good form - but Petra Kvitova? You could never have discounted it completely - she is a top-10 player after all - but I thought she'd have at least one bad match in her.
One bad match, like she did last year - she got to the semi final, in which she was pretty poor. She hits blazing winners but she has been prone to nerves in big matches and I thought that, in one match at least, the lights would catch her eyes - and probably in the final. But she was as good if not better in that match than at any other stage.
Consistency was her issue and, having overcome what could have been a long-standing flakiness problem at the first time of asking, she's certainly got the weapons to dominate the game, to be right at the top of it for a long time. You can't count her out of the US Open now and I see her being the next world number one.
Kvitova's got that 'big' game, she moves well - better than Sharapova - and she hits such big winners too. With her temperament coming together this could be the start of a long reign.
She played seven matches at Wimbledon and there wasn't an average one let alone a bad one. Consistency is the major problem in the women's game, and the inability to kill things off under pressure can be the breaking of many a promising female player - Ana Ivanovic springs to mind.
Whereas the men's game seems to have a lengthening between the top positions - first against second from third, who is being closed down by fourth - the women's game is tightening.
Right now how can you predict the US Open? What will happen to Clijsters? What will happen to Venus and Serena? And Li Na? I'm still a Li Na fan, she's 29 but she's new on the block in terms of her development. I think she could do big things at the US.
And one who's not there is Wozniacki, I'm afraid. She's still the world number one, and deservedly so because she turns up and largely dominates the Tour.
But, when all the other top players are playing, she hasn't got a big enough game. I don't see her winning a Grand Slam.
It's not mental, it's just her game - she's too defensive and she hasn't got the big attacking shots or physical power: when the attacking players are on song, they will beat her. The issue with the women's game is that those players only turn up for the Grand Slams - both mentally and in terms of actually entering the tournaments!
A very good attacking player will always beat a very good defensive player when her game is on - and in the Grand Slams, their game is always on.
Andy Murray found that out when he was a more defensive player than he is now, and he changed his game accordingly.
I worry that it's late for Caroline to change her game, to become more attacking. I'm not sure how they'll do it - by moving her to the middle or by somehow getting her on top of rallies first? But early 20s is almost middle aged for a women's player.
She's a cracking girl in every aspect, lovely off the court and superb on it, and I wish her well.
I think the debate about her being number one is nonsense as she absolutely deserves it, but can Caroline Wozniacki win a Grand Slam? I don't think so.