Fortunately/Unfortunately, I think that's all decided, when Petra's steps on the court (and what subsequently happens). I don't even think she knows.
PS: I find it funny, that Petra says so often how nervous she is, and dealing with pressure (if that's the real reason). However, neither she or her Management, have changed coaches, and/or brought in an assortment of advisors, and specialist, who can either help her with her tennis or mind/mental game. It's hasn't been working.
She/They appear 'Stuck In The Mud', making no tangible movements or adjustments? Hey, its ultimately, Petra's career, not ours. We're just the innocent (and not so innocent) by standers [and my/first last statement on this subject/personnel additions-Lol].
And Good Luck Today Against Flipkens Petra!!!!!!!
PS: ESPN said the 'Li Na, was considering retiring'. However, new coach, Carlos Rodriguez, has given her a new outlook on the game, by showing her different/new tactics, which have inspired her to play tennis longer.
That's what new, fresh additions, can do to your mind, perspective and outlook (not just confidence).
Once again, Good Luck Petra!!!!!!!!!