i remember that, during her match with henin... it went straight into the net! if your a serena fan you can say she was doing it to save her injured hand/thumb, if you're not a serena fan you can say she was trying to say to henin 'anything you can do i can do better!'. but she couldnt, so best just to say she did it to save her thumb! lol..
i loved that match!!! kinda off topic i know, but the way she came back out and just fought was awesome to watch. The way people laughed at her after and mocked her i think was appalling. it was a genuine injury, that she dealt with brilliantly.