Re: Serena Williams: “I probably played about 20 percent (against Wozniacki)”
Serena shouldn't say things like that, it is disrespectful to her opponent. She certainly did not play her best match while Caro played one of her better matches, but again it is part of the sport. You have to bring the best game when it is needed. How well one plays also depends on the opponent. Caro clearly exposed Serena's poor movement, that effects confidence and as a result effects things that people are usually good at (serve?).
She said herself "I’m older and I shouldn’t do that. There’s no excuse. I’ve just got to stop that. It’s silly." This applies to making statements like this one.