I can see how my tone of my previous responses have been unduly harsh, that would be because it's a bugbear of mine of those who quickly call the WTA a lottery after they bet on things they think should be sure bets because of surface factors (obviously the case here) , and thus write the sport off as a lottery.
So I'm going to reprise my last response and craft it with edification in mind, rather than umbrage.
1 - Kvitova is an attacking player, Wozniacki is a counterpuncher (a counterpuncher thrives on long rallies wearing down their opponent and either forcing errors first or forcing a poor return that can then be hit for an easy non-risk winner). Kvitova usually isn't interested in getting involved in long rallies, she seeks to hit a winner whenever there's even the slightest opening to. If she's invested in going deep in a tournament, then she can rally with the best of them and thus she'll show more patience, but at a venue she doesn't care for she's not going to be patient enough to wait for the RIGHT ball to hit for a winner, she's going to go for it as soon as she can even to the wrong ball. That leads to her hitting a lot of unforced errors which is what naturally leads to her poor results. So when she faces a capable counterpuncher like Woznaicki at a venue she doesn't care for at all, that means she's in trouble unless she finds a purple patch of form and simply has a day where all but everything she goes for hits the lines.
Kvitova's winner vs UE count was 38 v 40. That's -2 pts.
Wozniacki's winner vs UE count was 22 v 13. That's +9 pts.
At an aggregate, that's a total of +11 pts in Wozniacki's favor. 11 pts is basically 3 games. That's how many more games she won than Kvitova did: 14 vs 11 (7-5 7-6).
Notice the difference in UE: a whopping +27 in favor of Wozniacki. This match was decided on Kvitova's unwillingness to engage in lengthy rallies. Unforced errors, need it be said, are not forced errors. They're balls she had no excuse for not getting back in play.
2 - Time away from the game. Wozniacki announced her decision to return to the WTA at the end of June. Besides keeping her fitness and tennis skills in shape since retiring, that's basically 2 months she's had to dedicate herself fulltime to getting up to speed. Part of her decision return must've been seeing the tour depth beyond the top 5 players as being weak enough for her to be able maybe claim another Slam title or two, esp. on her fave surface. And no doubt her knowledge of Justine Henin's gambit back in 2010 also played a role. Significantly both are former #1 ranked players, these aren't journeywomen returning to the tour after time off (like Vera Zvonareva: God knows why she decided to return after almost 3 years away, her capacity to sddo anything doesn't come near Wozniacki's).
3 - WTA bets are predicated on odds. I'm not saying never bet Kvitova against a former hardcourt champion or even a capable hardcourt player, nor am I saying she cannot beat these players. I said you don't take her as a favourite against them at NYK. A very specific recommendation. In the past I only ever look to bet against Kvitova at NYK, because her record elsewhere always meant she was pretty much a fave most times. Now had she been paying +150 against Wozniacki, then things would've been different. Then there's value for the possibility that she has a day where her attempted winners find the lines even if she's going for them off the wrong return balls because of impatience. But she's never paying that much in a match like this, so such a consideration never got to exist.
...continued...