Just watched Andy Murray win his quarter final, and noted that Miss Williams lost her match. Why did I put this under "test preparation"? Because if great sporting events teach us anything, it is preparation preparation preparation. Just because your competition is ranked number one in the world, does not mean you cannot win: unless you psych yourself into believing you cannot win.
And it is the same for test prep. You might walk into the testing room with a perfect GPA, or something less; it doesn't matter. It's what you do on the day.
Ace, game, set, match!