I'm not at the level of insulting my faves just because and yes surface does matter, when all your life you trained and tailored your game to it but now you're at a point where you play worse than a club level player is ridicilous, Petra even at her best struggled with outdoor conditions but indoors there's nothing to struggle with and she's in Europe, so no asthma issues.
You just don't get it do you!!? What is so hard to understand?
Petra just can't show up and win anywhere, if her game, work ethic, will, instinct, confidence and timing are completely shot (as it appears to be now)!!
Maybe, she can do that on grass, cause grass is not a true bounce, good footing surface (unlike indoor hardcourt), and Petra's game is tailor made for it. However, if she doesn't feast on a compliant opponent to gain form, she can loose early on grass as well. Makarova beat her last year at Eastbourne (though in fairness, Makarova had already played a preceding grass tournament, when Petra didn't, but you get the point).
And there's no legitimate tennis reason why Petra should have poor results on Outdoor Hardcourt. That's all mental for Petra (as she showed when she won Montreal, New Haven and made the semi's of Cincy, and last years Australian Open run). That success, only demonstrates how inconsistent Petra and her team are at gearing her up for specific parts of the season and events (along with practicing at Prostojev during her off time).