*Update*
Guess what I found out? I found out that
most people that use their index-finger to press buttons Y, X, A and B, press the buttons slower than players that use their thumb for those buttons.
Look at this image and notice that the opposable-thumb has more muscle than the rest of the fingers... Amazing, right? That means your thumb's flexture is greater than the rest of the fingers! Of course all your thumb is the slowest finger, but it's opposable, so it can move in areas of the Gamecube controller that your other fingers can't, without even having to move your hand. If you are pressing the Y-button with your index-finger, and you want to C-stick, you have to move your
hand in order to get to the C-stick, and that takes longer than using your thumb to get to the C-stick, because you don't have to move your whole hand if you wish to C-stick.
